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Unformatted text preview: 8 August 2007 Homework Service Book Physics Chapters 23 to 64
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contact: homework@physics.utexas.edu Homework Service Book — Physics
00 Editing Examples
0001 Basic Templates
0002 UserDeﬁned Macros
0003 Figure Files
0004 Basic Control Structures
0005 Advanced Control Structures
0006 Special Purpose Templates
0007 Basic Functions
0008 Special Functions
0009 Basic TEX Techniques
0010 Basic Tables
0011 Special Use Tables
0012 Using Macros in TEX
0013 Basic PSTricks Techniques
0014 Basic Graphs
0015 Using Figure Files in PSTricks
0016 Special Figures
0017 Using Macros in PSTricks
0018 Basic PPCHTeX Techniques
0019 PPCHTeX and PSTricks
0020 Basic Biology Templates
0021 Basic Chem Templates
0022 Basic PPCHTeX Structures
0023 Electron Dot Templates
0024 Complicated Chem Structures
0025 Basic CS Templates
0026 CS Structures
0027 Basic Math Templates
0028 Math Graphs
0029 Basic Physics Templates
0030 Physics Figures
0099 Associated problems in Chapter 00
01 Physics and Measurement
0101 The SI System
0102 Standard Unit for Length, Mass, and
Time
0103 Derived Units
0104 The Building Blocks of Matter
0105 Density and Atomic Mass
0106 Dimensional Analysis
0107 Conversion of Units
0108 OrderofMagnitude Calculations
0109 Signiﬁcant Digits and Measurements
0110 Elementary Error Analysis
0111 Mathematical and Scientiﬁc Notation
0112 Coordinate Systems
0113 Mathematics Overview
0114 Scientiﬁc Method
0115 Scaling 2 0116 Problem Solving Strategy
0117 Measurement Tools
0199 Associated problems in Chapter 01
02 Motion in One Dimension
0201 Displacement
0202 Velocity and Speed
0203 Average Velocity for Motion along a
Straight Line
0204 Instantaneous Velocity and Speed
0205 Acceleration
0206 OneDimensional Motion with Constant Acceleration
0207 Freely Falling Objects
0208 OneDimensional Motion: Calculus
Techniques
0209 Relative Velocities
0210 Frame of Reference
0299 Associated problems in Chapter 02
03 Vectors
0301 Coordinate Systems and Frames of Reference
0302 Vector and Scalar Quantities
0303 Some Properties of Vectors
0304 Methods of Solving Triangles
0305 Graphical Addition of Vectors
0306 Components of a Vector
0307 Adding Vector Components
0308 Unit Vectors
0309 Vector Kinematics
0310 The Vector Dot (Scalar) Product
0311 The Vector Cross Product
0399 Associated problems in Chapter 03
04 Motion in Two Dimensions
0401 Position and Displacement
0402 Average and Instantaneous Velocity
0403 Average and Instantaneous Acceleration
0404 TwoDimensional Motion with Constant Acceleration
0405 Graphical Solutions
0406 Projectile Motion
0407 Uniform Circular Motion
0408 Tangential and Radial Acceleration
0409 Relative Velocity
0410 Relative Acceleration
0411 Relative Motion at High Speeds
0499 Associated problems in Chapter 04
05 The Laws of Motion
0501 The Concept of Force Homework Service Book — Physics
0502 Newton’s First Law and Inertial
Frames
0503 Inertial Mass
0504 Newton’s Second Law
0505 Weight
0506 Contact and Normal Forces
0507 Hooke’s Law
0508 Combining Forces
0509 Newton’s Third Law
0510 Free Body Diagrams in Problem Solving
0511 Static Applications of Newton’s Law
0512 Dynamic Applications of Newton’s
Law
0513 Friction
0514 Other Resistive Forces (Terminal Velocity)
0515 The Fundamental Forces of Nature
0599 Associated problems in Chapter 05
06 Circular Motion and Newton’s Laws
0601 Newton’s Second Law Applied to Uniform Circular Motion
0602 Banked and Unbanked Curves
0603 Nonuniform Circular Motion
0604 Circular Motion in Accelerated Frames
0605 Circular Motion in the Presence of Resistive Forces
0606 Numerical Modeling (Euler’s Method)
in Particle Dynamics
0699 Associated problems in Chapter 06
07 Work and Energy
0701 Forms of Energy
0702 Kinetic Energy
0703 Work
0704 Work: a General Constant Force
0705 Work: the Gravitational Force
0706 Work: a Spring Force
0707 Work: a General Varying Force
0708 Kinetic Energy and the WorkEnergy
Theorem
0709 The Nonisolated System – Conservation of Energy
0710 Kinetic Friction
0711 Power
0712 Work and Energy in Three Dimensions
0713 Energy and the Automobile
0714 Kinetic Energy at High Speeds
0715 Simple and Compound Machines
0799 Associated problems in Chapter 07 3 08 Potential Energy and Conservation
of Energy
0801 Potential Energy
0802 Spring Potential Energy
0803 Conservative and Nonconservative
Forces
0804 Conservative Forces and Potential Energy
0805 Conservation of Mechanical Energy
0806 Changes in Mechanical Energy
0807 Relationship Between Conservative
Forces and Potential Energy
0808 Energy Diagrams and the Equilibrium
of a System
0809 Work Done on a System by an External
Force
0810 Conservation of Energy in General
0811 MassEnergy Equivalence
0812 Quantization of Energy
0899 Associated problems in Chapter 08
09 Linear Momentum and Collisions
0901 Linear Momentum
0902 Impulse and Momentum
0903 Conservation of Linear Momentum
0904 Elastic Collisions
0905 Inelastic Collisions
0906 OneDimensional Collisions
0907 Two and ThreeDimensional Collisions
0908 The Center of Mass
0909 Finding the Center of Mass by Integration
0910 Motion of a System of Particles (Explosions)
0911 Energy of a System of Particles
0912 Energy and Momentum Conservation
in Collisions
0913 Center of Mass Reference Frame
0914 Rocket Propulsion
0999 Associated problems in Chapter 09
10 Rotation of a Rigid Object About a
Fixed Axis
1001 Angular Position, Velocity and Acceleration
1002 Kinematic Equations for Uniformly
Accelerated Rotational Motion
1003 Vector Nature of Angular Quantities
1004 Relationships Between Angular and
Linear Quantities Homework Service Book — Physics
1005
1006
1007
1008 Rotational Kinetic Energy
Calculation of Moments of Inertia
Torque
Relationship Between Torque and Angular Acceleration
1009 Work, Power, and Energy in Rotational
Motion
1010 Problem Solving in Rotational Dynamics
1099 Associated problems in Chapter 10
11 Rolling Motion, Angular Momentum, and Torque
1101 Rotational Plus Translational Motion:
Rolling
1102 The Kinetic Energy of Rolling
1103 The Forces of Rolling
1104 The YoYo
1105 The Torque Vector
1106 Angular Momentum of a Particle
1107 General Motion: Angular Momentum,
Torque of a System of Particles
1108 Rotation of a Rigid Body About a
Fixed Axis
1109 Rotational Imbalance
1110 Conservation of Angular Momentum
1111 Precession: Gyroscopes and Tops
1112 Rotating Frames of Reference: Inertial
Forces
1113 Coriolis Eﬀect
1114 Quantization of Angular Momentum
1199 Associated problems in Chapter 11
12 Static Equilibrium and Elasticity
1201 The Conditions for Equilibrium of a
Rigid Object
1202 Solving Statics Problems
1203 Stability and Balance: Center of Gravity
1204 Levers and Pulleys
1205 Bridges and Scaﬀolding
1206 Arches and Domes
1207 Couples
1208 Other Objects in Static Equilibrium
1209 Static Equilibrium in an Accelerated
Frame
1210 Elasticity: Stress and Strain
1211 Fracturing
1299 Associated problems in Chapter 12
13 Oscillatory Motion
1301 Simple Harmonic Motion 1302
1303
1304
1305
1306 4 Mass Attached to a Spring
Forces in Simple Harmonic Motion
Energy in Simple Harmonic Motion
The Simple Pendulum
The Physical Pendulum and Torsion
Pendulum
1307 Simple Harmonic Motion Related to
Uniform Circular Motion
1308 Damped Oscillations
1309 Forced Oscillations: Resonance
1399 Associated problems in Chapter 13
14 The Law of Gravity
1401 Newton’s Law of Gravity
1402 Gravitational Force Due to a System of
Particles
1403 Free Fall Acceleration and the Gravitational Force
1404 Gravitation Inside the Earth
1405 Kepler’s Laws: Planetary and Satellite
Motion
1406 The Gravitational Field
1407 Gravitational Potential Energy
1408 Escape Velocity
1409 Energy: Planetary and Satellite Motion
1410 Gravitational Force: Extended Object
& Particle
1411 Gravitational Force: Particle & Spherical Mass
1412 Principle of Equivalence
1499 Associated problems in Chapter 14
15 Fluid Mechanics
1501 States of Matter
1502 Density and Speciﬁc Gravity
1503 Pressure
1504 Fluids at Rest: Variation of Pressure
with Depth
1505 Pressure Measurements (Atmospheric,
Gauge)
1506 Pascal’s Principle (Hydraulics)
1507 Buoyant Forces and Archimedes’ Principle
1508 Fluid Dynamics
1509 Streamlines and the Equation of Continuity
1510 Bernoulli’s Equation
1511 Transport Phenomena
1512 Other Applications of Fluid Dynamics
1513 Energy from the Wind Homework Service Book — Physics
1514 Viscosity
1515 Surface Tension and Capillarity
1516 Pumps: the Heart
1599 Associated problems in Chapter 15
16 Wave Motion
1601 Wave Characteristics and Propagation
1602 Transverse and Longitudinal Waves
1603 Speed of a Traveling Wave
1604 Energy Conservation
1605 OneDimensional Traveling Waves
1606 Periodic Waves (Harmonic, Electromagnetic)
1607 Superposition and Interference of
Waves
1608 The Speed of Waves on Strings
1609 Reﬂection and Transmission of Waves
1610 Refraction of Waves
1611 Diﬀraction of Waves
1612 Sinusoidal Waves
1613 Energy Transmitted by Waves on
Strings
1614 The Linear Wave Equation
1615 Phasors
1699 Associated problems in Chapter 16
17 Sound Waves
1701 Characteristics of Sound Waves
1702 Speed of Sound Waves
1703 Periodic Sound Waves
1704 Energy and Intensity of Sound Waves
1705 The Doppler Eﬀect
1706 Quality of Sound (Noise)
1707 The Ear
1708 Sources of Musical Sound
1709 Digital Sound Recording
1710 Motion Picture Sound
1711 Sonar, Ultrasound, and Ultrasound
Imaging
1799 Associated problems in Chapter 17
18 Superposition and Standing Waves
1801 Superposition of Sinusoidal Waves
1802 Interference of Sinusoidal Waves
1803 Standing Waves in General
1804 Standing Waves in a String Fixed at
Both Ends
1805 Forced Vibrations and Resonance
1806 Standing Waves in Air Columns
1807 Standing Waves in Rods, Plates, and
Membranes
1808 Complex Waves 5 1809 Beats: Interference in Time
1810 Shock Waves and the Sonic Boom
1811 Harmonic Analysis and Synthesis
1812 Wave Packets and Dispersion
1899 Associated problems in Chapter 18
19 Temperature
1901 Atomic Theory of Matter
1902 The Zeroth Law of Thermodynamics:
Thermal Equilibrium
1903 Celsius and Fahrenheit Temperature
Scales
1904 The ConstantVolume Gas Thermometer and the Kelvin Scale
1905 Thermal Expansion of Solids and Liquids
1906 Macroscopic Description of an Ideal
Gas
1907 Problem Solving: Ideal Gas Law
1999 Associated problems in Chapter 19
20 Heat and the First Law of Thermodynamics
2001 Heat and Thermal Energy
2002 Internal Energy
2003 Heat Capacity and Speciﬁc Heat
2004 Heat Capacity of Gases
2005 Heat Capacity of Solids
2006 Latent Heat
2007 Phase Diagrams
2008 Calorimetry
2009 Work and Heat in Thermodynamic
Processes
2010 The First Law of Thermodynamics
2011 Work and the P V Diagram for a Gas
2012 Some Applications of the First Law of
Thermodynamics
2013 Heat and Energy Transfer
2014 Global Warming and Greenhouse
Gases
2099 Associated problems in Chapter 20
21 The Kinetic Theory of Gases
2101 Molecular Model of an Ideal Gas
2102 Speciﬁc Heat of an Ideal Gas
2103 Adiabatic Processes for an Ideal Gas
2104 The Equipartition of Energy
2105 The Boltzmann Distribution Law
2106 Pressure, Temperature, and RMS
Speed
2107 Distribution of Molecular Speeds
2108 Translational Kinetic Energy Homework Service Book — Physics
2109 Mean Free Path
2110 Van der Waals’ Equation of State
2111 Vapor Pressure and Humidity
2112 Diﬀusion
2113 Failure of the Equipartition Theorem
2199 Associated problems in Chapter 21
22 Heat Engines, Entropy, & Thermodynamics
2201 The Second Law of Thermodynamics
2202 Heat Engines
2203 Reversible and Irreversible Processes
2204 The Carnot Engine
2205 Gasoline and Deisel Engines
2206 Heat Pumps and Refrigerators
2207 Entropy
2208 Entropy Changes in Irreversible Processes
2209 Entropy on a Microscopic Scale
2210 Human Metabolism
2211 Energy Availability: Heat Death
2212 Statistical Interpretation of Entropy
and the Second Law
2213 Third Law: Maximum Eﬃciencies
2299 Associated problems in Chapter 22
23 Electric Fields
2301 Static Electricity: Electric Charge
2302 Quantized Charge
2303 Insulators and Conductors
2304 Induced Charge: the Electroscope
2305 Coulomb’s Law
2306 Conserved Charge
2307 The Electric Field
2308 Electric Field Due to a Point Charge
2309 Electric Field Due to an Electric Dipole
2310 Electric Field Due to a Line of Charge
2311 Electric Field Due to a Charged Sheet
2312 Electric Field Due to a Continuous
Charge Distribution
2313 Electric Field Lines
2314 Electric Fields and Conductors
2315 A Point Charge in a Electric Field
2316 A Dipole in a Electric Field
2317 Motion of Charged Particles in a Uniform Electric Field
2318 The Oscilloscope
2399 Associated problems in Chapter 23
24 Gauss’s Law
2401 Electric Flux
2402 Gauss’s Law 6 2403 Application: Charged Insulators
2404 Application: Charged Isolated Conductors
2405 Application: Cylindrical Symmetry
2406 Application: Planar Symmetry
2407 Application: Spherical Symmetry
2408 Conductors in Electrostatic Equilibrium
2409 Experimental Proof of Gauss’ Law and
Coulomb’s Law
2499 Associated problems in Chapter 24
25 Electric Potential
2501 Electric Potential Energy
2502 Potential Diﬀerence and Electric Potential
2503 Equipotential Surfaces
2504 Calculating the Potential from the
Field
2505 Potential & Energy: Point Charges
2506 Potential & Energy: Systems of Point
Charges
2507 Potential & Energy: Electric Dipoles
2508 Potential & Energy:
Continuous
Charge Distributions
2509 Potential & Energy: Charged Conductor
2510 Calculating the Field from the Potential
2511 Electrostatic Potential Energy: the
Electron Volt
2512 The Millikan Oil Drop Experiment
2513 Cathode Ray Tube: TV, Computer
Monitors, and Oscilloscopes
2514 The Van de Graaﬀ Generator and
Other Applications
2599 Associated problems in Chapter 25
26 Capacitance and Dielectrics
2601 Deﬁnition of Capacitance
2602 Calculation of Capacitance
2603 Combinations of Capacitors
2604 Energy Stored in a Charged Capacitor
2605 Capacitors with Dielectrics
2606 Dielectrics from a Molecular Level
2607 Dielectrics and Gauss’ Law
2608 Electric Dipole in an External Electric
Field
2609 Electrostatic Applications
2699 Associated problems in Chapter 26
27 Current and Resistance Homework Service Book — Physics
2701 Electric Current
2702 Current Density and Drift Speed
2703 Resistance and Resistivity
2704 Ohm’s Law
2705 Microscopic View of Ohm’s Law
2706 Resistance and Temperature
2707 Semiconductors
2708 Superconductors
2709 Electrical Energy and Power
2710 Power in Household Circuits
2711 Electrical Hazards: Leakage Currents
2712 Electrical Energy in the Heart
2799 Associated problems in Chapter 27
28 Direct Current Circuits
2801 Electromotive Force and Terminal
Voltage
2802 Work, Energy, and EMF
2803 Resistance: Series Circuits
2804 Resistance: Series/Parallel Combinations
2805 Potential Diﬀerence Between Two
Points
2806 Complicated Circuits: Kirchoﬀ’s Rules
2807 RC Circuits
2808 Electrical Instruments: Ammeter and
Voltmeter
2809 Household Wiring and Electrical
Safety
2810 Conduction of Electrical Signals by
Neurons
2811 Transducers and the Thermocouple
2899 Associated problems in Chapter 28
29 Magnetic Fields
2901 Magnetic Fields and Forces
2902 Magnetism from Electric Currents
2903 Magnetic Force on a CurrentCarrying
Conductor
2904 Torque on a Current Loop in a Uniform
Magnetic Field
2905 Motion of a Charged Particle in a Magnetic Field
2906 Applications of the Motion of Charged
Particles in a Magnetic Field
2907 Crossed Fields: Discovery of the Electron
2908 The Hall Eﬀect
2909 Galvanometers, Motors, Loudspeakers
2910 Cyclotrons and Synchrotrons
2911 Mass Spectrometer 7 2999 Associated problems in Chapter 29
30 Sources of the Magnetic Field
3001 The BiotSavart Law
3002 Magnetic Field Due to a Straight Wire
3003 Magnetic Force Between Two Parallel
Conductors
3004 Ampere’s Law
3005 The Magnetic Field of Current Loops
3006 The Magnetic Field Along the Axis of
a Solenoid
3007 A CurrentCarrying Coil as a Magnetic
Dipole
3008 Magnetic Flux
3009 Gauss’s Law in Magnetism
3010 Displacement Current and the Generalized Ampere’s Law
3011 Magnetism and Electrons: Spin
3012 Magnetism in Matter
3013 Diamagnetism
3014 Paramagnetism
3015 Ferromagnetism
3016 Magnetic Field of the Earth
3099 Associated problems in Chapter 30
31 Faraday’s Law
3101 Faraday’s Law of Induction
3102 Motional EMF
3103 Lenz’s Law
3104 Induced EMF in a Moving Conductor
3105 Induced Electric Fields
3106 Electric Field from a Changing Magnetic Flux
3107 Generators and Motors
3108 Eddy Currents
3109 Maxwell’s Equations
3110 Sound Systems, Computer Memory,
the Seismograph
3199 Associated problems in Chapter 31
32 Inductance
3201 Inductors and Inductance
3202 SelfInductance, SelfInduced EMF
3203 RL Circuits
3204 Energy in a Magnetic Field
3205 Energy Density of a Magnetic Field
3206 Mutual Inductance
3207 Oscillations in an LC Circuit
3208 The RLC Circuit
3209 Critical Magnetic Fields
3210 Magnetic Properties of Superconductors Homework Service Book — Physics
3299 Associated problems in Chapter 32
33 Alternating Current Circuits
3301 AC Sources
3302 Phasors
3303 Resistors in an AC Circuit
3304 Inductors in an AC Circuit
3305 Capacitors in an AC Circuit
3306 LC and RLC Circuits Without a Generator
3307 The RLC Series Circuit
3308 Damped Oscillations in an RLC Circuit
3309 Power in an AC Circuit
3310 Resonance in a Series RLC Circuit
3311 Impedance Matching
3312 Filter Circuits
3313 The Transformer and Power Transmission
3314 ThreePhase AC
3399 Associated problems in Chapter 33
34 Electromagnetic Waves
3401 Maxwell’s Equations and Hertz’s Discoveries
3402 Plane Electromagnetic Waves
3403 Speed of Electromagnetic Waves
3404 Energy Carried by Electromagnetic
Waves: Poynting Vector
3405 Momentum and Radiation Pressure
3406 Radiation from an Inﬁnite Current
Sheet
3407 The Production of Electromagnetic
Waves by an Antenna
3408 Properties of Electromagnetic Waves
3409 The Spectrum of Electromagnetic
Waves
3410 The Doppler Eﬀect for Electromagnetic Waves
3411 Radio and Television
3499 Associated problems in Chapter 34
35 The Nature of Light and Geometric
Optics
3501 The Nature of Light
3502 WaveParticle Duality
3503 The Speed of Light
3504 Reﬂection
3505 Transmission and Refraction
3506 The Law of Refraction
3507 Dispersion and Prisms
3508 Huygens’ Principle
3509 Total Internal Reﬂection 8 3510 Fermat’s Principle
3511 Mixing Pigments
3512 Luminous Intensity
3599 Associated problems in Chapter 35
36 Geometric Optics
3601 Two Types of Image
3602 Images Formed by Flat Mirrors
3603 Images Formed by Concave Mirrors
3604 Images Formed by Convex Mirrors
3605 Spherical Mirrors: Ray Tracing
3606 Images Formed by Refracting Surfaces
3607 Atmospheric Refraction
3608 Images Formed by Thin Lenses
3609 Combinations of Lenses and Mirrors
3610 Thin Lenses: Ray Tracing
3611 Lensmaker’s Equation
3612 The Camera
3613 The Eye and Corrective Lenses
3614 The Simple Magniﬁer
3615 The Compound Microscope
3616 The Telescope
3617 Lens and Mirror Aberrations
3699 Associated problems in Chapter 36
37 Interference of Light Waves
3701 Conditions for Interference
3702 Double Slit Interference: Young’s Experiment
3703 Coherence
3704 Intensity Distribution of the DoubleSlit Interference Pattern
3705 Phasor Addition of Waves
3706 Change of Phase Due to Reﬂection
3707 Interference in Thin Films
3708 The Michelson Interferometer
3709 Using Interference to Read CDs and
DVDs
3799 Associated problems in Chapter 37
38 Diﬀraction and Polarization
3801 Diﬀraction
3802 Huygens’ Principle and Diﬀraction
3803 Huygens’ Principle and the Law of Refraction
3804 SingleSlit Diﬀraction
3805 Intensity in SingleSlit Diﬀraction
3806 Using Phasors to Add Harmonic Waves
3807 Fraunhofer and Fresnel Diﬀraction
3808 Resolution of SingleSlit and Circular
Apertures
3809 Resolution of Telescopes and Micro Homework Service Book — Physics
scopes: the λ Limit
3810 Resolution of the Human Eye and Useful Magniﬁcation
3811 Diﬀraction by a Double Slit
3812 The Diﬀraction Grating
3813 Gratings: Dispersion and Resolving
Power
3814 XRays
3815 Diﬀraction of XRays by Crystals
3816 Polarization of Light Waves
3817 Polarization by Reﬂection
3818 The Spectrometer and Sprctroscopy
3899 Associated problems in Chapter 38
39 Relativity
3901 Galilean Coordinate Transformations
3902 Lorenz Coordinate Transformations
3903 Postulates: Speed of Light
3904 The MichelsonMorley Experiment
3905 Consequences of Special Relativity
3906 The Lorentz Transformation for Displacements
3907 The Lorentz Transformation for Time
3908 The Lorentz Transformation for Velocities
3909 Relativistic Momentum and Relativistic Form of Newton’s Laws
3910 Relativistic Energy
3911 Mass as a Measure of Energy
3912 Photon Momentum
3913 Conservation of Relativistic Momentum, Mass, and Energy
3914 Doppler Shift for Light
3915 Pair Production and Annihilation
3916 Matter and Antimatter
3917 General Relativity and Accelerating
Reference Frames
3999 Associated problems in Chapter 39
40 The Quantum Theory of Light
4001 The Photon, the Quantum of Light
4002 Hertz’s Experiments: Light as an Electromagnetic Wave
4003 Blackbody Radiation and Planck’s Hypothesis
4004 Light Quantization and the Photoelectric Eﬀect
4005 The Compton Eﬀect
4006 ParticleWave Complementarity, Duality: Double Slits
4007 Eﬀect of Gravity on Light 9 4008 The Wave Function
4009 Electron Microscopes
4099 Associated problems in Chapter 40
41 The Particle Nature of Matter
4101 The Atomic Nature of Matter
4102 The Composition of Atoms
4103 Molecules
4104 The Bohr Atom
4105 Quantum Model of the Hydrogen Atom
4106 FranckHerz Experiment
4199 Associated problems in Chapter 41
42 Matter Waves
4201 de Broglie Waves
4202 The Time Independent Schrodinger
Equation
4203 The DavissonGermer Experiment
4204 Fourier Integrals
4205 The Heisenberg Uncertainty Principle
4206 Wave Groups and Dispersion
4207 WaveParticle Duality
4208 String Waves and Matter Waves
4299 Associated problems in Chapter 42
43 Quantum Mechanics in One Dimension
4301 The Hydrogen Atom
4302 The Born Interpretation
4303 The TimeDependent Schrodinger
Equation
4304 Wavefunction for a Free Particle
4305 Wavefunctions in the Presence of
Forces
4306 Particle in a Box
4307 Energies of a Trapped Electron
4308 Wave Functions of a Trapped Electron
4309 The Finite Square Well
4310 More Electron Traps
4311 Two and ThreeDimensional Electron
Traps
4312 The Quantum Oscillator
4313 Expectation Values
4314 Observables and Operators
4399 Associated problems in Chapter 43
44 Tunneling Phenomena
4401 The Square Barrier
4402 Barrier Penetration: Some Applications
4403 Decay Rates
4404 The Scanning Tunneling Microscope
4499 Associated problems in Chapter 44 Homework Service Book — Physics
45 Quantum Mechanics in Three Dimensions
4501 ThreeDimensional Schrodinger Equation
4502 Particle in a ThreeDimensional Box
4503 Central Forces and Angular Momentum
4504 Space Quantization
4505 Quantization of Angular Momentum
and Energy
4506 Atomic Hydrogen and Hydrogenlike
Ions
4599 Associated problems in Chapter 45
46 Atomic Structure
4601 Some Properties of Atoms
4602 Atomic Spectra
4603 Orbital Magnetism and the Normal
Zeeman Eﬀect
4604 Electron Spin
4605 The SpinOrbit Interaction and Other
Magnetic Eﬀects
4606 Angular Momenta and Magnetic
Dipole Moments
4607 The SternGerlach Experiment
4608 Magnetic Resonance
4609 Electron Clouds
4610 Exchange Symmetry and the Exclusion
Principle
4611 Multiple Electrons in Rectangular
Traps
4612 Electron Interactions and Screening Effects
4613 The Periodic Table
4614 Isotopes
4615 XRay Spectra and Moseley’s Law
4616 Atomic Transitions
4617 Lasers and Holography
4618 How Lasers Work
4699 Associated problems in Chapter 46
47 Statistical Physics
4701 The MaxwellBoltzmann Distribution
4702 Quantum Statistics, Indistinguishability, and the Pauli Exclusion Principle
4703 Applications of BoseEinstein Statistics
4704 An Application of FermiDirac Statistics: The FreeElectron Gas Theory of
Metals
4799 Associated problems in Chapter 47 10 48 Molecular Structure
4801 Bonding Mechanisms
4802 Weak (van der Waals) Bonds
4803 Polyatomic Molecules
4804 Diatomic Molecules: Molecular Rotation and Vibration
4805 Molecular Spectra
4806 Electron Sharing and the Covalent
Bond
4807 Bonding in Complex Molecules
4899 Associated problems in Chapter 48
49 The Solid State
4901 Bonding in Solids
4902 Electrical Properties of Solids
4903 Energy Levels in a Crystalline Solid
4904 Insulators
4905 Metals
4906 Classical FreeElectron Model
4907 Quantum Theory of Metals
4908 Band Theory of Solids
4909 Semiconductor Devices
4910 Doped Semiconductors
4911 The pn Junction
4912 The Junction Rectiﬁer
4913 The LightEmitting Diode (LED)
4914 Transistors and Integrated Circuits
4999 Associated problems in Chapter 49
50 Superconductivity
5001 Magnetism in Matter
5002 A Brief History of Superconductivity
5003 Some Properties of Type I Superconductors
5004 Type II Superconductors
5005 Other Properties of Superconductors
5006 Electronic Speciﬁc Heat
5007 BCS Theory
5008 Energy Gap Measurements
5009 Josephson Tunneling
5010 HighTemperature Superconductivity
5011 Applications of Superconductivity
5099 Associated problems in Chapter 50
51 Nuclear Structure
5101 Discovering the Nucleus
5102 Some Nuclear Properties
5103 Binding Energy and Nuclear Forces
5104 Nuclear Models
5105 Radioactivity
5106 Decay Processes
5107 Alpha Decay Homework Service Book — Physics
5108 Beta Decay
5109 Gamma Decay
5110 HalfLife and Rate of Decay
5111 Decay Series
5112 Radioactive Dating
5113 Measuring Radiation Dosage
5114 Natural Radioactivity
5199 Associated problems in Chapter 51
52 Nuclear Physics Applications
5201 Nuclear Reactions
5202 Reaction Cross Section
5203 Interactions Involving Neutrons
5204 Nuclear Fission
5205 A Model for Nuclear Fission
5206 Nuclear Reactors
5207 A Natural Nuclear Reactor
5208 Nuclear Fusion
5209 Thermonuclear Fusion in the Sun and
Other Stars
5210 Controlled Thermonuclear Fusion
5211 Recent Fusion Energy Developments
5212 Interaction of Particles with Matter
5213 Radiation Damage in Matter
5214 Radiation Detectors
5215 Radiation Therapy
5216 Tracers
5217 Tomography Imaging: CAT Scans and
Emission Tomography
5218 NMR and MRI
5299 Associated problems in Chapter 52
53 Particle Physics
5301 Elementary Particles
5302 The Fundamental Forces in Nature
5303 Particle Accelerators and Detectors
5304 Particle Exchange
5305 Particles and Antiparticles
5306 Mesons and the Beginning of Particle
Physics
5307 Classiﬁcation of Particles
5308 Conservation Laws
5309 Particle Stability and Resonances
5310 Antiproton in a Bubble Chamber
5311 Leptons
5312 Hadrons
5313 Strange Particles and Strangeness
5314 Elementary Particle Production; Measurement of Properties
5315 The Eightfold Way
5316 Quarks 11 5317 Electroweak Theory and the Standard
Model
5318 Quasars
5319 Grand Uniﬁed Theory
5399 Associated problems in Chapter 53
54 Astrophysics and Cosmology
5401 Stars and Galaxies
5402 The Birth and Death of Stars
5403 General Relativity: Gravity and the
Curvature of Space
5404 The Expanding Universe
5405 The Cosmic Connection
5406 Cosmic Background Radiation
5407 Dark Matter
5408 The Big Bang
5409 Early History of the Universe
5410 The Future of the Universe
5411 Problems and Perspectives
5499 Associated problems in Chapter 54
55 Probability Distributions
5501 Uncertainites
5502 Parent and Sample Distributions
5503 Mean and Standard Deviation of Distributions
5504 Binomial Distribution
5505 Poisson Distribution
5506 Gaussian or Normal Error Distribution
5507 Lorentzian Distribution
5599 Associated problems in Chapter 55
56 Error Analysis (see 01:11)
5601 Instrumental and Statistical Uncertainties
5602 Propagation of Errors
5603 Speciﬁc Error Formulas
5604 Application of Error Equations
5699 Associated problems in Chapter 56
57 Estimates of Mean and Errors
5701 Method of Least Squares
5702 Statistical Fluctuations
5703 χ2 Test of a Distribution
5799 Associated problems in Chapter 57
58 Monte Carlo Techniques
5801 Introduction
5802 Random Numbers
5803 Random Numbers from Probability
Distributions
5804 Speciﬁc Distributions
5805 Eﬃciency
5899 Associated problems in Chapter 58 Homework Service Book — Physics
59 LeastSquares Fit to a Straight Line
5901 Dependent and Independent Variables
5902 Method of Least Squares
5903 Minimizing χ2
5904 Error Estimation
5905 Some Limitations of the LeastSquares
Method
5906 Alternate Fitting Methods
5999 Associated problems in Chapter 59
60 LeastSquares Fit to a Polynomial
6001 Determinate Solution
6002 Matrix Solution
6003 Independent Parameters
6004 Nonlinear Functions
6099 Associated problems in Chapter 60
61 LeastSquares Fit to an Arbitrary
Function
6101 Nonlinear Fitting
6102 Searching Parameter Space
6103 GridSearch Mechod
6104 GradientSearch Method
6105 Expansion Methods
6106 The Marquardt Method
6107 Comments on the Fits
6199 Associated problems in Chapter 61
62 Fitting Composite Curves
6201 Lorentzian Peak on Quadratic Background
6202 Area Determination
6203 Composite Plots
6299 Associated problems in Chapter 62
63 Direct Application of the MaximumLikelihood Method
6301 MaximumLikelihood Method
6302 Computer Example
6399 Associated problems in Chapter 63
64 Testing the Fit
6401 χ2 Test of Goodness of Fit
6402 LinearCorrelation Coeﬃcient
6403 F Test
6404 Conﬁdence Intervals
6405 Monte Carlo Tests
6499 Associated problems in Chapter 64 12 Chapter 23, section 1, Static Electricity: Electric Charge 13 tumbling in a clothes dryer?
Conceptual Q16 01
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. 1. gravitational force
2. air pressure There is an old saying that the lightning
never strikes the same place twice.
Is this true?
1. Yes
2. No 3. electrical force
4. The dryer heat caused some of the fabrics
to melt together.
5. The clothes are electrically neutral. Conceptual Q16 11
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 22 E05
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. Static cling makes your clothes stick together.
What causes this to happen? When combing your hair, you scuﬀ electrons from your hair onto the comb.
Is your hair then positively or negatively
charged? What about the comb? 1. friction created by tumbling clothes
1. positively charged; negatively charged
2. the nature of the material
2. Both are positively charged.
3. external forces to the clothes
2. Both are negatively charged.
4. forces of nature
4. negatively charged; positively charged
Hewitt CP9 11 E01
23:01, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the mass of an object change
when it acquires a positive charge?
1. decreases
2. increases
3. doesn’t change
4. More information is needed.
Hewitt CP9 22 E02
23:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why do clothes often cling together after 5. Neither is charged.
Hewitt CP9 22 E06
23:01, highSchool, multiple choice, < 1 min,
ﬁxed.
At some automobile tollcollecting stations,
a thin metal wire sticks up from the road and
makes contact with cars before they reach the
toll collector.
What is the purpose of this wire?
1. To discharge the automobile
2. To count the vehicles
3. To warn the drivers
4. To transfer electrons to the automobile Chapter 23, section 1, Static Electricity: Electric Charge 14 is less than the net charge of the ions.
5. To transfer positive particles to the automobile
Hewitt CP9 22 E07
23:01, highSchool, numeric, < 1 min, ﬁxed.
Why are the tires for trucks carrying gasoline and other ﬂammable ﬂuids manufactured
to be electrically conducting?
1. To move the negative charges from the
truck to the ground and avoid a ﬁre 2. The net charge of the negative electrons
is greater than the net charge of the ions.
3. The net charge of the negative electrons
has the same magnitude as the net charge of
the ions.
4. Sometimes the net charge of the negative
electrons is greater than the net charge of the
ions and sometimes it is less.
5. Unable to determine 2. To neutralize the charges on the trucks
3. To make the truck move faster Hewitt CP9 22 E18
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. To make the truck easier to drive
5. To move the positive charges from the
truck to the ground and avoid ﬁre The ﬁve thousand billion freely moving
electrons in a penny repel one another.
Why don’t they ﬂy oﬀ the penny? Hewitt CP9 22 E11
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. 1. They are attracted to the ﬁve thousand billion positively charged protons in the
atomic nuclei of atoms in the penny. What happens to the mass of an object
when it acquires a positive net charge by the
transfer of electrons? 2. They don’t have enough speed.
3. They cause a jam when they try to ﬂy
away. 1. decreases
2. increases
3. Doesn’t change
4. Unable to determine
Hewitt CP9 22 E13
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. The shell of the penny prevents the electrons from ﬂying.
5. The electrons attract each other.
Hewitt CP9 22 E27
23:01, highSchool, multiple choice, < 1 min,
ﬁxed.
If you are caught outdoors in a thunderstorm, why should you not stand under a
tree? In a crystal of salt there are electrons and
positive ions.
How does the net charge of the electrons
compare with the net charge of the ions? 1. A tree is likely to accumulate an electric
charge that can kill you if you touch the tree. 1. The net charge of the negative electrons 2. A tree attracts electrically polarized air Chapter 23, section 1, Static Electricity: Electric Charge
molecules that can have a harmful eﬀect on
your body. 15 painted.
What does the phenomenon of polarization
have to do with this? 3. A tree is likely to be hit by lightning
because you and the tree now form a polarized
system. 1. The air is polarized and makes the paint
ﬂow uniformly. 4. A tree is likely to be hit by lightning
because it provides a path of less resistance
between the cloud overhead and the ground. 2. The paint particles in the mist are polarized and as such are attracted to the charged
chassis. 5. The tree has more resistance than the air
and thus is likely to be hit by lightning. 3. The car is polarized and easily attracts
paint particles. Hewitt CP9 22 E30
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. The car is magnetic; with some polarization of the paint, it will be easier for the paint
to be attracted to the car. What keeps an inﬂated balloon from falling
down if you rub it against your hair and place
it against a wall? Holt SF 17Rev 03
23:01, highSchool, numeric, > 1 min, wordingvariable. 1. Rubbing leaves a balloon electrically
charged; the charged balloon polarizes the
wall. A negatively charged balloon has 3.5 µC of
charge.
How many excess electrons are on this balloon? 2. Rubbing distorts the atoms inside the
ballon and polarizes it.
3. When you rub the balloon against your
hair, the balloon may have some oil attached
to it, which can be sticky.
4. When you rub the balloon against your
hair, it will remove some mass from the balloon and make it lighter.
5. Rubbing polarizes the air inside of the
balloon. Holt SF 17Rev 40
23:01, highSchool, numeric, > 1 min, wordingvariable.
Calculate the net charge on a substance
consisting of a combination of 7.0 × 1013 protons and 4.0 × 1013 electrons.
Holt SF 17Rev 42
23:01, highSchool, numeric, > 1 min, wordingvariable. Hewitt CP9 22 E32
23:01, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 2
One gram of copper has 9.48 × 1021 atoms,
and each copper atom has 29 electrons.
a) How many electrons are contained in
2.00 g of copper? When the chassis of a car is moved into a
painting chamber, a mist of paint is sprayed
around the chassis. When the car is given a
sudden electric charge, the mist is attracted
to it, and the car is quickly and uniformly Part 2 of 2
b) What is the total charge of these electrons? Chapter 23, section 2, Quantized Charge
Hewitt CP9 22 E31
23:02, highSchool, multiple choice, < 1 min,
ﬁxed.
How can a charged atom (an ion) attract a
neutral atom?
1. The charged atom can hit the neutral
atom and make it positively charged or negatively charged.
2. The charged atom can emit x rays to
induce ionization of the neutral atom.
3. The charged atom can produce secondary
electrons to interact with the neutral atom
and make it positively charged or negatively
charged.
4. An ion polarizes a nearby neutral atom,
so that the part of the atom nearer to the ion
acquires a charge opposite to the charge of the
ion, and the part of the atom farther from the
ion acquires a charge of the same sign as the
ion.
Holt SF 18Rev 35
23:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A certain moving electron has a kinetic energy of 1.00 × 10−19 J.
a) Calculate the speed necessary for the
electron to have this energy.
Part 2 of 2
b) Calculate the speed of a proton, having a
kinetic energy of 1.00 × 10−19 J. 16 Chapter 23, section 3, Insulators and Conductors 17 helps conduct electricity.
Conceptual 24 Q01
23:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Why are metals generally good conductors
of electricity?
1. Metals have free electrons in their outer
shell.
2. Metals have strong bonding with other
atoms. Conceptual 24 Q05
23:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How can a hole moving through a semiconductor be like an electric charge moving
through the same material?
1. If an electron moves into the hole, the
hole changes places with the electron.
2. A hole is a location of a proton. 3. Metals have more protons.
Conceptual 24 Q02
23:03, highSchool, multiple choice, < 1 min,
wordingvariable. Conceptual 24 Q10
23:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How do we normally classify air? Take the point of view of an electron moving among other electrons and atoms in a
material.
Describe your motion in an insulator. 1. electrical conductor 1. free to move around but will occasionally
bump into an atom 3. semiconductor 2. electrical insulator 4. superconductor
2. can move around but with diﬃculty
3. can move around freely with no limitations Hewitt CP9 22 E26
23:03, highSchool, multiple choice, < 1 min,
ﬁxed. 4. bonded to an atom and cannot stray from
that location Why are metalspiked shoes not a good idea
for golfers on a stormy day? Conceptual 24 Q03
23:03, highSchool, multiple choice, < 1 min,
ﬁxed. 1. The metal spikes can accumulate a net
charge.
2. The spikes attract electrical charges. How does salt water conduct electricity?
1. Salt dissolved in water gives out ions,
which helps conduct electricity.
2. Salt insreases the density of water, which
helps conduct electricity.
3. Salt decreases the density of water, which 3. There might be electrical sparks between
the two spikes because they are conductors.
4. The metal spikes provide an eﬀective electrical path from cloud to ground.
Hewitt CP9 22 E29
23:03, highSchool, multiple choice, < 1 min, Chapter 23, section 3, Insulators and Conductors
ﬁxed. 18 23:03, highSchool, multiple choice, < 1 min,
ﬁxed. Why is a good conductor of electricity is
also a good conductor of heat?
1. They all carry energies for both electricity
and heat.
2. For both electricity and heat, the conduction is via atoms, which in a metal are
loosely bound, easy ﬂowing, and easy to start
moving.
3. If there is a current through a conductor, there should also be heat produced by
resistance.
4. Because both a good conductor for heat
and a good conductor for electricity don’t
have bound electrons in them.
5. For both electricity and heat, the conduction is via electrons, which in a metal are
loosely bound, easy ﬂowing, and easy to start
moving.
Hewitt CP9 22 E37
23:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose that a metal ﬁle cabinet is charged.
How will the charge concentration at the
corners of the cabinet compare with the
charge concentration on the ﬂat parts of the
cabinet?
1. Higher than the concentration at the ﬂat
parts.
2. Lower than the concentration at the ﬂat
parts.
3. Equal everywhere
4. More information is needed. A neutral ball is suspended by a string.
A positively charged insulating rod is placed
near the ball, which is observed to be attracted to the rod.
This is because
1. the ball becomes positively charged by
induction.
2. the ball becomes negatively charged by
induction.
3. the number of electrons in the ball is
greater than in the rod.
4. the string is not a perfect conductor.
5. there is a rearrangement of the electrons
in the ball.
Inside a Sphere
23:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Imagine a charge in the center of a conducting, hollow sphere. There is no net charge on
the sphere, and the sphere is not connected to
ground. q What will happen if the charge is moved a
little away from the center?
1. The charge will return to the center.
2. The charge will remain stationary.
3. The charge will move away from the center. 5. None of these
Induced Metal Ball 4. All of these can happen, depending on the
size of the charge. Chapter 23, section 3, Insulators and Conductors
5. There is not enough information to tell.
Inside Parallel Plates
23:03, highSchool, multiple choice, > 1 min,
ﬁxed.
Imagine a charge in the middle between
two parallel plate conductors. There is no net
charge on the plates, and the plates are not
connected to ground. q What will happen if the charge is moved a
little away from the middle?
1. The charge will return to the middle.
2. The charge will remain stationary.
3. The charge will move away from the middle.
4. All of these can happen, depending on the
size of the charge.
5. There is not enough information to tell. 19 Chapter 23, section 4, Induced Charge: the Electroscope
Charging Two Metal Balls
23:04, highSchool, multiple choice, > 1 min,
wordingvariable.
Two uncharged metal balls, X and Z, stand
on insulating glass rods. A third ball, carrying
a negative charge, is brought near the ball Z
as shown in the ﬁgure. A conducting wire is
then run between X and Z and then removed.
Finally the third ball is removed.
conducting wire
− Z X When all this is ﬁnished
1. ball X is negative and ball Z is positive.
2. ball X is positive and ball Z is negative.
3. balls X and Z are both positive, but ball
X carries more charge than ball Z.
4. balls X and Z are both negative.
5. balls X and Z are still uncharged.
6. ball X is neutral and ball Z is positive.
7. ball X is neutral and ball Z is negative.
8. ball X is positive and ball Z is neutral.
9. ball X is negative and ball Z is neutral.
10. balls X and Z are both positive, but ball
Z carries more charge than ball X.
Hewitt CP9 22 E08
23:04, highSchool, multiple choice, < 1 min,
ﬁxed.
An electroscope is a simple device consisting of a metal ball that is attached by a conductor to two thin leaves of metal foil pro 20 tected from air disturbance in a jar. When the
ball is touched by a charged body, the leaves
that normally hang straight down, spread
apart.
Why?
1. The charge transfers to the leaves through
the metal ball. Since the leaves have identical charges, they are pushed away from each
other.
2. The charge transfers to the leaves through
the glass. Since the leaves have diﬀerent
charges, they are pushed away from each
other.
3. The charge transfers to the leaves through
the metal ball. Since the leaves have diﬀerent charges, they are pushed away from each
other.
4. The charge transfers to the two leaves
through the glass. Since the leaves have identical charges, they are pushed away from each
other.
5. None of these
Hewitt CP9 22 E09
23:04, highSchool, multiple choice, < 1 min,
ﬁxed.
The leaves of a charged electroscope collapse in time. At higher altitudes they collapse more rapidly.
Why is this true?
1. Cosmic rays have higher ionization capability at higher altitudes in air, allowing for
easier discharge.
2. Cosmic rays ionize more air at lower altitudes.
3. Cosmic rays hit the leaves and knock the
electrical charges oﬀ the leaves.
4. There is less air at higher altitudes. Chapter 23, section 4, Induced Charge: the Electroscope 21 5. Colder temperatures exist at higher altitudes. 23:04, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 22 E10
23:04, highSchool, multiple choice, < 1 min,
ﬁxed. When one material is rubbed against another, electrons jump readily from one to the
other.
Why don’t protons do that? Is it necessary for a charged body to actually touch the ball of the electroscope for the
leaves to diverge?
1. Yes; charged particles transfer to the ball
only with contact.
2. No; the charged particles will attract or
push electrons out of the ball. 1. Electrons can attract each other while
protons repel each other.
2. Electrons are much lighter than protons.
3. Electrons are much heavier than protons. 3. Yes; particles can’t move through the
air. 4. Electrons are easily dislodged from the
outer regions of atoms, but protons are held
tightly within the nucleus. 4. No; the charged particles will move
through the air. 5. Electrons travel at the speed of light while
protons move very slowly. 5. None of these
Hewitt CP9 22 E14
23:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Can an object be charged negatively with
the help of a positively charged object?
1. Yes, by bringing the positivelycharged
object near the object to be charged, then
discharging the far side
2. Yes, by bringing the positivelycharged
object near the object to be charged, then
discharging the near side
3. Yes, by rubbing the two objects together
4. Yes, by letting the two objects touch each
other
5. No; negative charges can only be obtained
with other negatively charged objects.
Hewitt CP9 22 E16 Chapter 23, section 5, Coulomb’s Law
Charges on Spheres 01
23:05, highSchool, numeric, > 1 min, normal. 22 4. F = 5/2 F
5. F = 5/4 F Part 1 of 2
Two conducting spheres have identical
radii. Initially they have charges of opposite sign and unequal magnitudes with the
magnitude of the positive charge larger than
the magnitude of the negative charge. They
attract each other with a force of 0.108 N
when separated by 0.5 m.
Initial ++
++ −
− The spheres are suddenly connected by a thin
conducting wire, which is then removed.
Connected + + Now the spheres repel each other with a force
of 0.036 N.
Final + + What is the magnitude of the positive
charge?
Part 2 of 2
What is the negative charge? 6. F = 25 F
7. F = 50 F
8. F = 100 F
9. F = 25/2 F
10. F = 25/4 F
Conceptual 16 01
23:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Based on electric charges and separations, which of the following atomic bonds
is strongest? (You are interested only in the
relative strengths, which depend only on the
relative charges and distances.)
1. A +1 sodium atom separated by 2.0 distance units from a −1 chlorine atom in table
salt
2. A +1 hydrogen atom separated by 1.0
distance units from a −2 oxygen atom in table
salt Compare two coulomb forces
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. 3. A +4 sodium atom separated by 1.5 distance units from a −2 oxygen atom in table
salt Two charges q1 and q2 are separated by a
distance d and exert a force F on each other.
What is the new force F , if charge 1 is
increased to q1 = 5 q , charge 2 is decreased
to q2 = q2 /2, and the distance is decreased to
d = d/2? Choose one Conceptual 16 02
23:05, highSchool, numeric, > 1 min, normal. 1. F = 5 F Part 1 of 3
Assume that in interstellar space the distance between two electrons is about 0.1 cm.
The electric force between the two electrons
is 2. F = 10 F 1. attractive. 3. F = 20 F 2. repulsive. Chapter 23, section 5, Coulomb’s Law
Part 2 of 3
Calculate the electric force between these two
electrons.
Part 3 of 3
Calculate the gravitational force between
these two electrons.
Conceptual 16 03
23:05, highSchool, numeric, > 1 min, normal.
Part 1 of 3
Assume that in interstellar space the distance between two protons is about 0.1 cm.
The electric force between the two protons
is
1. attractive
2. repulsive
Part 2 of 3
Calculate the electric force between these two
protons. 23 Assume that you have two objects, one with
mass of 10 kg and the other with a mass of
15 kg, each with a charge of −0.03 C and
separated by a distance of 2 meters,
What is the electric force that these objects
exert on one another?
Part 2 of 2
What is the gravitational force between
them?
Conceptual 16 Q14
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Object A and object B are initially uncharged and are separated by a distance of 1
meter. Suppose 10,000 electrons are removed
from object A and placed on object B, creating an attractive force between A and B. An
additional 10,000 electrons are removed from
A and placed on B and the objects are moved
so that the distance between them increases
to 2 meters.
By what factor does the electric force between them change? Part 3 of 3
Calculate the gravitational force between
these two protons. 1. Doubles Conceptual 16 04
23:05, highSchool, numeric, > 1 min, normal. 3. Quadruples 2. Triples 4. Halves Part 1 of 2
Assume that you have two objects, one with
a mass of 10 kg and the other with a mass of
15 kg, each with a charge of −0.03 C and
separated by a distance of 2 m.
What is the electric force that these objects
exert on one another? Conceptual Q16 02
23:05, highSchool, numeric, < 1 min, wordingvariable. Part 2 of 2
What is the gravitational force between
them? If you triple the distance between two
charged objects, by what factor is the electric force aﬀected? Conceptual 16 4
23:05, highSchool, numeric, > 1 min, ﬁxed. Conceptual Q16 03
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 2 5. No change Chapter 23, section 5, Coulomb’s Law
If you double the charge on one of two
charged objects, how does the force between
them change? 24 7. − + + 8. − + + 9. − + + Conceptual Q16 04
23:05, highSchool, multiple choice, < 1 min,
wordingvariable. 10. − + + Three small spheres carry equal amounts of
electric charge. They are equally spaced and
lie along the same line. Conceptual Q16 13
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. 1. Double
2. Quadruple
3. Triple
4. Halve
5. Does not change − + + What is the direction of the net electric
force on each charge due to the other charge?
1. − + + Part 1 of 2
Object A and object B are initially uncharged and separated by a distance of 2 meters. Suppose 10,000 electrons are removed
from object A and placed on object B, creating an electric force between A and B.
The electric force is
1. repulsive. 2. − + + 2. attractive.
3. zero. 3. − + + 4. − + + 5. 6. − − + + Part 2 of 2
An additional 10,000 electrons are removed
from A and placed on B.
By what factor does the electric force
change? + Conceptual Q16 20
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. + A charge of +1 coulomb is place at the 0cm mark of a meter stick. A charge of −1
coulomb is placed at the 100cm mark of the Chapter 23, section 5, Coulomb’s Law
same meter stick.
Is it possible to place a proton somewhere
on the meter stick so that the net force on it
due to the two charges is 0?
1. Yes; to the right of the 50cm mark
2. Yes; to the left of the 50cm mark
3. No 25 diﬃcult to remove the inner electrons?
1. The inner electrons are stuck on the nucleus.
2. The outer electrons feel no force.
3. For the outer electrons, the attractive
force of the nucleus is largely canceled by the
repulsive force of the inner electrons. Conceptual Q16 21
23:05, highSchool, numeric, < 1 min, ﬁxed. 4. No processes can aﬀect the inner electrons. A charge of +1 coulomb is place at the 0cm mark of a meter stick. A charge of +4
coulombs is placed at the 100cm mark of the
same meter stick.
Where should a proton be placed on the
meter stick so that the net force on it due to
the two charges is 0? 5. The outer electrons are always free electrons. Hewitt CP9 22 E01
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
We do not feel the gravitational forces between ourselves and the objects around us
because these forces are extremely small.
Why don’t we usually feel electrical forces? Hewitt CP9 22 E19
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the magnitude of the electrical force between a pair of charged objects
change when the objects are moved twice as
far apart?
1. doubles
2. quadruples
3. Reduces to one quarter of original value 1. The force is small.
4. Reduces to one half of original value
2. We have the same number of positively
charged particles and negatively charged particles in our bodies.
3. Electrical force cannot be felt.
4. Gravitational forces overwhelm the electric forces.
Hewitt CP9 22 E15
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. 5. Doesn’t change
Hewitt CP9 22 E20
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the magnitude of the electrical
force between change a pair of charged particles when they are brought to half their
original distance of separation?
1. doubles Why is it relatively easy to strip the outer
electrons from a heavy atom like uranium
(which then becomes a uranium ion), but very 2. quadruples Chapter 23, section 5, Coulomb’s Law 26 3. Reduces to one quarter of original value
4. Reduces to one half of original value Hewitt CP9 22 E34
23:05, highSchool, multiple choice, < 1 min,
ﬁxed. 5. Doesn’t change
Hewitt CP9 22 E22
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Two equal charges exert equal forces on
each other.
What if one charge has twice the magnitude
of the other?
1. The bigger charge will exert a force twice
as strong.
2. The bigger charge will exert a force four
times as strong.
3. The smaller charge will exert a force twice
as strong. Consider two charged plates with the same
net charge on each. Imagine a proton at rest
a certain distance from a negatively charged
plate; after being released it collides with the
plate. Then imagine an electron at rest the
same distance from a positively charged plate.
In which case will the moving particle have
the greater speed when the collision occurs?
1. The proton and the electron will have the
same speed on impact.
2. The proton will have the greater speed on
impact.
3. The electron will have the greater speed
on impact.
4. It cannot be determined. 4. The smaller charge will exert a force four
times as strong. Hewitt CP9 22 P01
23:05, highSchool, numeric, > 1 min, normal. 5. The forces will be equal.
Hewitt CP9 22 E33
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If you place a free electron and a free proton
in the same electric ﬁeld, how will the forces
acting on them compare?
1. Equal in magnitude and direction
2. Diﬀerent in both magnitude and direction
3. In the same direction but not equal in
magnitude
4. Equal in magnitude, but opposite in direction
5. Comparison is not possible. Part 1 of 2
Two point charges are separated by 6 cm,
with an attractive force between them of 20 N.
Find the force between them when they are
separated by 12 cm. The Coulomb constant
is 8.99 × 109 N · m2 /C2 .
Part 2 of 2
If the two charges have equal magnitude, what
is the magnitude of each charge for the original force of 20 N?
Hewitt CP9 22 P02
23:05, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Two pellets, each with a charge of 1 ×
10−6 C, are located 0.03 m apart.
The Coulomb constant is 8.99 ×
10−9 N · m2 /C2 and the universal gravitational constant is 6.67259 × 10−11 m3 /kg · s2 . Chapter 23, section 5, Coulomb’s Law
What is the electric force between the pellets?
Part 2 of 2
What mass would experience this same force
in the Earth’s gravitational ﬁeld?
Hewitt CP9 22 P04
23:05, highSchool, numeric, > 1 min, normal.
Part 1 of 3
Atomic physicists usually ignore the eﬀect
of gravity within an atom. To see why, we may
calculate and compare the magnitude of the
ratio of the electrical force and gravitational
Fe
between an electron and a proton
force
Fg
separated by a distance of 1 m.
The Coulomb constant is 8.98755 ×
9
10 N · m2 /C2 , the gravitational constant is
6.67259 × 10−11 m3 /kg · s2 , the mass of a proton is 1.67262 × 10−27 kg, the mass of an
electron is 9.10939 × 10−31 kg, the charge on
a proton is 1.602 × 10−19 C, and the charge
on an electron is −1.602 × 10−19 C.
What is the magnitude of the electrical
force?
Part 2 of 3
What is the magnitude of the gravitational
force?
Part 3 of 3
What is the ratio of the magnitude of the
electrical force to the magnitude of the gravitational force?
Hewitt CP9 22 R02
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does the gravitational force between
the Earth and moon predominate over electric
forces?
1. Because the masses of the Earth and
moon are very large.
2. Because both the Earth and the moon are 27 electrically neutral.
3. Because the distance between the Earth
and the moon is very large.
4. Because there is no electric charge on the
moon.
Hewitt CP9 22 R11
23:05, highSchool, multiple choice, < 1 min,
ﬁxed.
How is Coulomb’s law similar to Newton’s
law of gravitation? How is it diﬀerent?
1. Both forces vary inversely as the square of
the separation distance between the two objects; electrical forces may be either attractive
or repulsive, whereas gravitational forces are
only attractive.
2. Both forces are proportional to the product of the mass of the two objects; electrical
forces may be either attractive or repulsive,
whereas gravitational forces are only attractive.
3. Both forces are proportional to the same
constant; electrical forces are only present
on earth, whereas gravitational forces exist
everywhere.
4. Both forces vary inversely as the square
of the separation distance between the two
objects; electrical forces are only present on
earth, whereas gravitational forces can exist
everywhere.
5. Both forces are proportional to the product of the masses of the two objects; electrical
forces are only present on earth, whereas gravitational forces exist everywhere.
6. Both forces proportional to the same constant; electrical forces may be either attractive or repulsive, whereas gravitational forces
are only attractive.
Holt SF 17A 01 Chapter 23, section 5, Coulomb’s Law
23:05, highSchool, numeric, < 1 min, wordingvariable.
A balloon rubbed against denim gains a
charge of −8.0 µC.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 .
What is the electric force between the balloon and the denim when the two are separated by a distance of 5.0 cm? (Assume that
the charges are located at a point.)
Holt SF 17A 02
23:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Two identical conducting spheres are
placed with their centers 0.30 m apart. One is
given a charge of +12 × 10−9 C and the other
is given a charge of −18 × 10−9 C.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 .
a) Find the electric force exerted on one
sphere by the other.
Part 2 of 2
The spheres are connected by a conducting
wire.
b) After equilibrium has occurred, ﬁnd the
electric force between the two spheres.
Holt SF 17A 03
23:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A small cork with an excess charge of
+6.0 µC is placed 0.12 m from another cork,
which carries a charge of −4.3 µC.
The Coulomb constant is 8.98755 ×
9
10 N · m2 /C2 .
a) What is the magnitude of the electric
force between the corks?
Part 2 of 4
b) Is this force attractive or repulsive?
1. attractive 28 2. repulsive
3. Unable to determine
Part 3 of 4
c) How many excess electrons are on the negative cork?
Part 4 of 4
d) How many electrons has the positive cork
lost?
Holt SF 17A 04
23:05, highSchool, numeric, > 1 min, wordingvariable.
Two electrostatic point charges of
+60.0 µC and +50.0 µC exert a repulsive
force on each other of 175 N.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 .
What is the distance between the two
charges?
Holt SF 17B 01
23:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Three point charges, q1 = +6.0 µC, q2 =
+1.5 µC, and q3 = −2.0 µC, lie along the
xaxis at x = 0 cm, x = 3.0 cm, and x = 5.0
cm, respectively.
The Coulomb constant is 8.99 ×
109 N · m2 /C2 .
a) What is the force exerted on q1 by the
other two charges? (To the right is positive.)
Part 2 of 3
b) What is the force exerted on q2 by the other
two charges? (To the right is positive.)
Part 3 of 3
c) What is the force exerted on q3 by the other
two charges? (To the right is positive.)
Holt SF 17B 02
23:05, highSchool, numeric, > 1 min, wording Chapter 23, section 5, Coulomb’s Law
variable.
Part 1 of 6
Four charged particles are placed so that
each particle is at the corner of a square. The
sides of the square are 15 cm. The charge at
the upper left corner is +3.0 µC, the charge at
the upper right corner is −6.0 µC, the charge
at the lower left corner is −2.4 µC, and the
charge at the lower right corner is −9.0 µC.
The Coulomb constant is 8.98755 ×
9
10 N · m2 /C2 .
a) What is the magnitude of the net electric
force on the +3.0 µC charge?
Part 2 of 6
b) What is the direction of this force (measured from the positive xaxis as an angle between −180◦ and 180◦ , with counterclockwise
positive)?
Part 3 of 6
c) What is the magnitude of the net electric
force on the −6.0 µC charge?
Part 4 of 6
d) What is the direction of this force (measured from the positive xaxis, with counterclockwise positive)? 29 Find the point (coordinate) between these
two charges where a charge of +3.00 × 10−9 C
should be placed so that the net electric force
on it is zero.
Holt SF 17C 02
23:05, highSchool, numeric, > 1 min, wordingvariable.
A charge q1 of −5.00 × 10−9 C and a charge
q2 of −2.00 × 10−9 C are separated by a distance of 40.0 cm.
Find the equilibrium position for a third
charge of +15.0 × 10−9 C by identifying its
distance from q1 .
Holt SF 17C 03
23:05, highSchool, numeric, > 1 min, ﬁxed.
An electron is released above the Earth’s
surface. A second electron directly below it
exerts just enough of an electric force on the
ﬁrst electron to cancel the gravitational force
on it.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 and the acceleration of gravity is 9.81 m/s2 .
Find the distance between the two electrons. Part 5 of 6
e) What is the magnitude of the net electric
force on the −9.0 µC charge? 1. 5.07424 cm Part 6 of 6
f) What is the direction of this force (as
an angle between −180◦ and 180◦ measured
from the positive xaxis, with counterclockwise positive)? 3. 5.07424 km Holt SF 17C 01
23:05, highSchool, numeric, > 1 min, wordingvariable.
A charge of +2.00 × 10−9 C is placed at the
origin, and another charge of +4.00 × 10−9 C
is placed at x = 1.5 m.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 . 2. 5.07424 m 4. 50.7424 m
5. 0.507424 m
Holt SF 17Rev 18
23:05, highSchool, numeric, > 1 min, ﬁxed.
At the point of ﬁssion, a nucleus of 235 U
that has 92 protons is divided into two smaller
spheres, each of which has 46 protons and a
radius of 5.9 × 10−15 m.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 . Chapter 23, section 5, Coulomb’s Law
What is the magnitude of the repulsive
force pushing these two spheres apart?
1. 4.75067 × 10 20 N /C 30 6. 94.359 N, attractive
Holt SF 17Rev 21
23:05, highSchool, numeric, > 1 min, wordingvariable. 2. 3496.5 N 4. 4.12586 × 10−11 N · m
5. None of these
6. Unable to determine
Holt SF 17Rev 19
23:05, highSchool, numeric, > 1 min, wordingvariable.
What is the electric force between a glass
ball that has +2.5 µC of charge and a rubber
ball that has −5.0 µC of charge when they are
separated by a distance of 5.0 cm?
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 .
Holt SF 17Rev 20
23:05, highSchool, numeric, > 1 min, wordingvariable.
An alpha particle (charge = +2.0 e) is sent
at high speed toward a gold nucleus (charge
= +79 e).
The Coulomb constant is 8.99 ×
109 N · m2 /C2 .
What is the electric force acting on the
alpha particle when the alpha particle is 2.0 ×
10−14 m from the gold nucleus?
1. 94.359 N, repulsive
2. 90.9069 N, repulsive
3. 90.9069 N, attractive
4. None of these
5. Unable to determine 3 nC
+ 1m N · m /C Part 1 of 2
Three positive point charges are arranged
in a triangular pattern in a plane, as shown
below.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 . 1m 3. 4.02599 × 10 34 1m
+
6 nC +
2 nC
Find the magnitude of the net electric force
on the 6 nC charge.
Part 2 of 2
b) What is the direction of this force (measured from the positive xaxis as an angle between −180◦ and 180◦ , with counterclockwise
positive)?
Holt SF 17Rev 22
23:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Two positive point charges, each of which
has a charge of 2.5 × 10−9 C, are located at
y = +0.50 m and y = −0.50 m.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 .
a) Find the magnitude of the resultant electrical force on a charge of 3.0 × 10−9 C located
at x = 0.70 m.
Part 2 of 2
b) What is the direction of this force (measured from the positive xaxis as an angle be Chapter 23, section 5, Coulomb’s Law
tween −180◦ and 180◦ , with counterclockwise
positive)? 31 tity of charge that would have to be placed on
each to produce the required force. Holt SF 17Rev 23
23:05, highSchool, numeric, > 1 min, wordingvariable. 1. 6.71571 × 1013 C Three point charges lie in a straight line
along the y axis. A charge of q1 = −9.0 µC is
at y = 6.0 m, and a charge of q2 = −8.0 µC is
at y = −4.0 m. The net electric force on the
third point charge is zero.
Where along the y −axis is this charge located? 3. 4.71571 × 1013 C Holt SF 17Rev 24
23:05, highSchool, numeric, > 1 min, wordingvariable.
A charge of +3.5 nC and a charge of +5.0
nC are separated by 40.0 cm.
Find the equilibrium position for a −6.0 nC
charge as a distance from the ﬁrst charge.
Holt SF 17Rev 45
23:05, highSchool, numeric, > 1 min, wordingvariable.
1.0 g of hydrogen contains 6.02 × 1023
atoms, each with one electron and one proton. Suppose that 1 g of hydrogen is separated into protons and electrons, that the
protons are placed at Earth’s north pole, and
that the electrons are placed at Earth’s south
pole.
Find the magnitude of the resulting compressional force on Earth. (The radius of
Earth is approximately 6.38 × 106 m.)
Holt SF 17Rev 47
23:05, highSchool, numeric, > 1 min, ﬁxed.
The moon (m = 7.36 × 1022 kg) is bound to
Earth (m = 5.98 × 1024 kg) by gravity.
The
Coulomb
constant
is
8.98755 × 109 N · m2 /C2 .
If, instead, the force of attraction were the
result of each having a charge of the same
magnitude but opposite in sign, ﬁnd the quan 2. 5.71649 × 1013 C 4. 5.71649 × 1014 C
5. 5.71649 × 1012 C
Holt SF 17Rev 48
23:05, highSchool, numeric, > 1 min, wordingvariable.
Two small metallic spheres, each with a
mass of 0.200 g, are suspended as pendulums
by light strings from a common point. They
are given the same electric charge, and the
two come to equilibrium when each string is
at an angle of 5.0◦ with the vertical.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 , and the acceleration of gravity
is 9.81 m/s2 .
If each string is 30.0 cm long, what is the
magnitude of the charge on each sphere?
Holt SF 17Rev 59
23:05, highSchool, numeric, > 1 min, wordingvariable.
Three identical point charges hang from
three strings, as shown.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 , and the acceleration of gravity
is 9.81 m/s2 . Chapter 23, section 5, Coulomb’s Law 45◦ 45◦
30.0 cm
+q
+
0.10 kg 30.0 cm
+q +q +
0.10 kg Fg +
0.10 kg What is the value of q ?
Holt SF 17Rev 63
23:05, highSchool, numeric, > 1 min, wordingvariable.
A DNA molecule (deoxyribonucleic acid)
is 2.17 µm long. The ends of the molecule
become singly ionized so that there is −1.60 ×
10−19 C on one end and +1.60 × 10−19 C
on the other. The helical molecule acts as
a spring and compresses 1.00 percent upon
becoming charged.
The value of Coulomb’s constant is
8.98755 × 109 N · m2 /C2 and the acceleration
of gravity is 9.8 m/s2 .
Find the eﬀective spring constant of the
molecule.
Magnitude of Force
23:05, highSchool, numeric, > 1 min, normal.
There are two identical small metal spheres
with charges 33 µC and −26.4 µC. The distance between them is 5 cm. The spheres
are placed in contact then set at their original distance.
The Coulomb constant is
8.98755 × 109 N · m2 /C2 .
Calculate the magnitude of the force between the two spheres at the ﬁnal position. 32 Chapter 23, section 7, The Electric Field
AlF 3
23:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 6
A conceptual model of aluminum triﬂouride
(AlF3 ) is approximately a square with charges
at the corners.
QA = 3 q
Q B = −q 2. EC
3. EC
4. EC
5. EC a
Q D = −q 7. EC
Q C = −q The magnitude of the electric ﬁeld EO at
the center O is given by
√ kq
2 2.
a
√ kq
= 2 2.
a
√ kq
=2 2 2 .
a
kq
= 2.
a
1 kq
.
=√
2 a2
4kq
= 2.
a
1 kq
.
=√
4 2 a2
kq
=3 2 .
a
8kq
= 2.
a
1 kq
=√
.
3 2 a2 √ kq
2 2.
a
√ kq
= 2 2.
a
√ kq
=2 2 2 .
a
3√
kq
=
−2
.
2
a2
3 kq
.
=
2 a2
9 kq
.
=
4 a2
√
kq
= 3− 2
.
a2
kq
=3 2 .
a
√ kq
=3 2 2 .
a
1 kq
=√
.
3 2 a2 1. EC = 4 6. EC
O 33 8. EC
9. EC 1. EO = 4 10. EC 2. EO Part 3 of 6
Determine the absolute value of tan α, where
α is the angle between the horizontal and the
electric ﬁeld at C due to the three charges at
A, B , and D.
√
2 2−1
1.  tan α = √
2 2+1
√
2.  tan α = 2 2 − 1
√
3.  tan α = 2 2 + 1
√
2 2+1
4.  tan α = √
2 2−1
1
5.  tan α = √
2 2−1
√
6.  tan α = 2 3. EO
4. EO
5. EO
6. EO
7. EO
8. EO
9. EO
10. EO Part 2 of 6
The magnitude of the electric ﬁeld EC at C
due to the 3 charges at A, B , and D is given
by 1
7.  tan α = √
2
8.  tan α = 2 √ 9.  tan α = 1
√
10.  tan α = 3 1
2+1 Chapter 23, section 7, The Electric Field a Part 4 of 6
Consider charges in a square again, but this
time with a diﬀerent assignment of charges
(shown in the ﬁgure below).
QA = q
QB = q O
QD = q 2. EO
3. EO
4. EO
5. EO
6. EO
7. EO
8. EO
9. EO
10. EO Q C = −q kq
=4 2
a
√ kq
=22
a
√ kq
=2 2 2
a
kq
=2
a
1 kq
=√
2 a2
1 kq
=√
5 2 a2
1 kq
=√
4 2 a2
kq
=3 2
a
√ kq
=3 2 2
a
1 kq
=√
3 2 a2 Part 5 of 6
Find the electric ﬁeld EC at C due to the 3
charges at A, B , and D for the setup in the
previous Part.
kq
a2
√ kq
2. EC = 2 2
a
kq
3. EC = 2 2
a 1. EC = 4 5. EC = kq
a2
√ 2+ 1
2 kq
a2 5 kq
2 a2
7 kq
=√
4 2 a2
kq
=3 2
a
√ kq
=3 2 2
a
1 kq
=√
3 2 a2 6. EC =
7. EC
8. EC Find EO at O .
1. EO 4. EC = 34 9. EC
10. EC Part 6 of 6
Again, determine tan α, where α as the angle
between the horizontal and the electric ﬁeld
at C due to the three charges at A, B , and D.
√
2 2−1
1. tan α = √
2 2+1
√
2. tan α = 2 2 − 1
√
3. tan α = 2 2 + 1
√
2 2+1
4. tan α = √
2 2−1
1
5. tan α = √
2 2−1
√
6. tan α = 2
1
7. tan α = √
2
8. tan α = 2 √ 1
2+1 9. tan α = 1
√
10. tan α = 3
Conceptual 17 01
23:07, highSchool, numeric, > 1 min, normal.
Part 1 of 4
The electric ﬁeld at a point in space is
deﬁned as the force per unit charge at that Chapter 23, section 7, The Electric Field
point in space. We can write the electric ﬁeld
E of a charge q at a distance d from that
charge, experienced by a charge Q, as
F
q
E=
=k 2
Q
d
The electric ﬁeld has a direction such that
it points toward negative charges and points
away from positive charges. Suppose your rub
a balloon in your hair and it acquires a static
charge of 3 × 10−9 C.
What is the strength of the electric ﬁeld
created by the balloon at a location 1 m due
north of the balloon?
Part 2 of 4
What is the direction of that electric ﬁeld?
1. south 35 6. upward
Conceptual Q16 08
23:07, highSchool, multiple choice, > 1 min,
wordingvariable.
Two small spheres carry equal amounts of
electric charge. There are equally spaced
points (a , b , and c) which lie along the same
line.
−
−
a
c
b
What is the direction of the net electric ﬁeld
at each point due to these charges?
1. a − b − c a − b − c a − b − c a − b − c a − b − c a − b − c a − b − c a − b − c 2. north
3. east 2. 4. west
5. downward 3. 6. upward
Part 3 of 4
You hair acquired an equal amount of positive
charge when you rubbed the balloon on your
head.
What is the strength of the electric ﬁeld
created by your head, at the location of your
feet, 1.5 meters below? 4. Part 4 of 4
What is the direction of that electric ﬁeld? 6. 1. south 5. 7. 2. north
3. east
4. west
5. downward 8. Chapter 23, section 7, The Electric Field 9. 10. a − a − b − b − c c Part 1 of 2
Two charged particles of equal magnitude
(+Q and −Q) are ﬁxed at opposite corners of
a square that lies in a plane (see ﬁgure below).
A test charge −q is placed at a third corner.
+Q −q
−Q
What is the direction of the force on the
test charge due to the two other charges? 2.
3.
4.
5.
6.
7.
8. Part 2 of 2
Let the side of the square be a. What is the
magnitude of the electric ﬁeld at the location
of −q due to the two charges: +Q and −Q.
1. 0 Force and Field
23:07, highSchool, multiple choice, > 1 min,
wordingvariable. 1. 36 kQ
a2
√ kQ
3. 2 2
a
√ kQ
4. 3 2
a
kQ
5. 2 2
a
kqQ
6. 2 2
a
kQ
7.
a
√ kQ
8. 2
a
√ kQ
9. 3
a
kQ
10. 2
a
2. Hewitt CP9 22 E28
23:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If a large enough electric ﬁeld is applied,
even an insulator will conduct an electric
current, as is evident in lightning discharges
through the air.
Explain how this happens, taking into account the opposite charges in an atom and
how ionization occurs.
1. The insulator itself can produce an electric ﬁeld under the inﬂuence of strong external
electric ﬁeld.
2. A neutral atom in an electric ﬁeld is electrically distorted; if the ﬁeld is strong enough,
ionization occurs with charges being torn from
each other. The ions then provide a conducting path for an electric current. Chapter 23, section 7, The Electric Field
3. If the ﬁeld is strong enough, all the electrons in an insulator will become free, causing
an electric current.
4. If the ﬁeld is strong enough, air around
the insulator would be ionized. The ionized
particles can hit the insulator to change it into
a conductor.
5. If the ﬁeld is strong enough, the protons
in a neutral atom will become neutrons.
Hewitt CP9 22 P03
23:07, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Usually the force of gravity on electrons is
neglected. To see why, we can compare the
force of the Earth’s gravity on an electron
with the force exerted on the electron by an
electric ﬁeld of magnitude of 10000 V/m (a
relatively small ﬁeld).
The acceleration of gravity is 9.8 m/s2 , the
mass of an electron is 9.10939 × 10−31 kg, and
the charge on an electron is −1.602 × 10−19 C.
What is the force exerted on the electron by
an electric ﬁeld of magnitude of 10000 V/m?
Part 2 of 2
What is the force of the Earth’s gravity on
the electron?
Hewitt CP9 22 P05
23:07, highSchool, numeric, > 1 min, normal.
A droplet of ink in an industrial inkjet
printer carries a charge of 1 × 10−10 C and is
deﬂected onto paper by a force of 0.0003 N.
Find the strength of the electric ﬁeld to
produce this force.
Hewitt CP9 22 P08
23:07, highSchool, numeric, > 1 min, normal.
Part 1 of 2
In 1909 Robert Millikan was the ﬁrst to ﬁnd
the charge of an electron in his nowfamous
oil drop experiment. In the experiment tiny
oil drops are sprayed into a uniform electric 37 ﬁeld between a horizontal pair of oppositely
charged plates. The drops are observed with
a magnifying eyepiece, and the electric ﬁeld is
adjusted so that the upward force q E on some
negatively charged oil drops is just suﬃcient
to balance the downward force m g of gravity.
Millikan accurately measured the charges on
many oil drops and found the values to be
wholenumber multiples of 1.6 × 10−19 C —
the charge of the electron. For this he won
the Nobel Prize.
The acceleration of gravity is 9.8 m/s2 .
If a drop of mass 6.53061 × 10−15 kg remains
stationary in an electric ﬁeld of 100000 N/C,
what is the charge on this drop?
Part 2 of 2
How many extra electrons are on this particular oil drop (given the presently known charge
of the electron)?
Holt SF 17D 01
23:07, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A charge of 5.00 µC is at the origin and a
second charge of −3.00 µC is on the positive
xaxis 0.800 m from the origin.
The Coulomb constant is 8.99 ×
109 N · m2 /C2 .
Find the magnitude of the electric ﬁeld at a
point P on the y axis 0.500 m from the origin.
Part 2 of 2
Determine the direction of this electric ﬁeld
(as an angle between −180◦ and 180◦ measured from the positive xaxis, with counterclockwise positive).
Holt SF 17D 02
23:07, highSchool, numeric, > 1 min, ﬁxed.
A proton and an electron in a hydrogen
atom are separated on the average by about
5.3 × 10−11 m.
The Coulomb constant is 8.99 ×
109 N · m2 /C2 .
What is the magnitude and direction of Chapter 23, section 7, The Electric Field
the electric ﬁeld set up by the proton at the
position of the electron?
1. 5.12068 × 1011 N/C away from the proton
2. 5.12068 × 1011 N/C toward the proton
3. 8.19309 × 10−8 N/C away from the proton
4. 8.19309 × 10−8 N/C toward the proton
5. 27.1396 N/C away from the proton
6. 27.1396 N/C toward the proton
Holt SF 17Rev 38
23:07, highSchool, numeric, > 1 min, wordingvariable.
Find the magnitude electric ﬁeld at a point
midway between two charges +30.0 × 10−9 C
and +60.0 × 10−9 C separated by a distance
of 30.0 cm.
The Coulomb constant is 8.99 ×
9
10 N · m2 /C2 .
Holt SF 17Rev 39
23:07, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A 2 µC point charge is on the xaxis at
x = 3 m , and a 5.7 µC point charge is on the
xaxis at x = 1 m .
The Coulomb constant is 8.98755 ×
9
10 N m2 /C2 .
Determine the magnitude of the net electric
ﬁeld at the point on the y axis where y = 2 m .
Part 2 of 2
Determine the direction of this electric ﬁeld
(as an angle between −180◦ and 180◦ measured from the positive xaxis, with counterclockwise positive.)
Holt SF 17Rev 43
23:07, highSchool, numeric, > 1 min, normal.
Part 1 of 2 38 READ AND DELETE: Comments by Yeung (21217). Solution code forgot to take
absolute value. The second part of the problem asks for the magnitude of the force on a
test charge but the some of the answers were
negative.
Consider three charges arranged as
shown.
The Coulomb constant is
8.99 × 109 N · m2 /C2 .
6 µC 1.5 µC + +
3 cm −2 µC
 2 cm What is the electric ﬁeld strength at a point
1 cm to the left of the middle charge?
Part 2 of 2
What is the magnitude of the force on a 2 µC
charge placed at this point?
Holt SF 17Rev 44
23:07, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
Consider three charges arranged in a triangle as shown.
The Coulomb constant is 8.99 ×
109 N · m2 /C2 .
y 0.3 m 5.0 nC
+ + x 6.0 nC
0.1 m
−3.0 nC
What is the net electric force on the charge
at the origin? Chapter 23, section 7, The Electric Field
Part 2 of 4
What is the direction of this force (as an angle
between −180◦ and +180◦ measured from the
positive xaxis, with counterclockwise positive)? of 30.0◦ , 150.0◦ , and 270.0◦ , as shown.
The Coulomb constant is 8.99 ×
109 N · m2 /C2 . q Part 3 of 4
What is the magnitude of the net electric ﬁeld
at the position of the charge at the origin? Holt SF 17Rev 50
23:07, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Three positive charges are arranged as
shown.
The Couloumb constant is 8.99 ×
9
10 N · m2 /C2 . 0.20 m 6.0 nC
+ 3.0 nC
+ +
5.0 nC 150.0◦ + + Part 4 of 4
What is the direction of the net electric ﬁeld
(as an angle between −180◦ and +180◦ measured from the positive xaxis, with counterclockwise positive). 39 q 30.0◦ 270.0◦ +
q
What is the resultant electric ﬁeld at the
center?
1. 0.0561875 N/C at 90◦
2. 0 N/C
3. 0.0561875 N/C at 270◦
4. 22.475 N/C at 90◦
5. 22.475 N/C at 270◦
6. 0.112375 N/C at 90◦
7. 0.112375 N/C at 270◦
8. None of these 0.60 m
Find the magnitude of the electric ﬁeld at
the fourth corner of the rectangle. Holt SF 17Rev 61
23:07, highSchool, multiple choice, > 1 min,
normal. Part 2 of 2
What is the direction of this electric ﬁeld (as
an angle between −180 and 180 measured
from the positive xaxis, with counterclockwise positive)? In a laboratory experiment, ﬁve equal negative point charges are placed symmetrically
around the circumference of a circle of radius
r, with one at 0◦ .
Calculate the electric ﬁeld at the center of
the circle. (Assume right and upward are
positive.) Holt SF 17Rev 56
23:07, highSchool, numeric, > 1 min, wordingvariable.
Three identical charges (q = +5.0 µC) are
along a circle with a radius of 2.0 m at angles 1. kC q
at 0◦
r2 2. 0 N/C Chapter 23, section 7, The Electric Field
3. kC
4. kC
5. kC q
at 180◦
r2
5q
at 180◦
r2
(5q )2
at 0◦
r2 6. Unable to determine
7. None of these
Three Conducting Spheres
23:07, highSchool, numeric, < 1 min, normal.
Consider three identical conducting spheres
of radius 1 cm arranged in an equilateral triangle. 10 cm 4C −1 C
7C
If the spheres are all connected by a thin
wire, what is the ﬁnal charge on the lower
lefthand sphere?
Three Point Charges 14
23:07, highSchool, numeric, > 1 min, normal.
Three equal charges of 4 µC are in the xy
plane. One is placed at the origin, another is
placed at (0.0, 30 cm), and the last is placed
at (15 cm, 0.0). The Coulomb constant is
9 × 109 N m2 /C2 .
Calculate the magnitude of the force on the
charge at the origin. 40 Chapter 23, section 8, Electric Field Due to a Point Charge
Hewitt CP9 22 E24
23:08, highSchool, multiple choice, < 1 min,
normal.
Suppose that the strength of the electric
ﬁeld about an isolated point charge has a
certain value at a distance of 1 m.
How will the electric ﬁeld strength compare
at a distance of 2 m from the point charge?
1. At twice the distance the ﬁeld strength
1
will be of the original value.
4
2. At twice the distance the ﬁeld strength
1
will be of the original value.
2
3. At twice the distance the ﬁeld strength
1
will be of the original value.
3
4. At twice the distance the ﬁeld strength
will be the same.
5. At twice the distance the ﬁeld strength
will be twice the original value.
Point Charge 02
23:08, highSchool, numeric, > 1 min, normal.
The value of the Eﬁeld at a distance of 70 m
from a point charge is 35 N/C. Its direction is
radially in toward the charge. The Coulomb
constant is 8.98755 × 109 N · m2 /C2 .
Find the magnitude and sign of the point
charge at the origin. 41 Chapter 23, section 12, Electric Field Due to a Continuous Charge Distribution
Concept 34 E37
23:12, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider a fusion torch.
If a starhot ﬂame is positioned between a
pair of large electrically charged plates (one
positive and the other negative) and materials
dumped into the ﬂame are dissociated into
bare nuclei and electrons, in which direction
will the nuclei move? In which direction will
the electrons move?
1. both toward the positive plate
2. toward the positive plate; toward the negative plate
3. toward the negative plate; toward the
positive plate
4. both toward the negative plate
Holt SF 17Rev 53
23:12, highSchool, numeric, > 1 min, wordingvariable.
Air becomes a conductor when the electric
ﬁeld strength exceeds 3.00 × 106 N/C.
Determine the maximum amount of charge
that can be carried by a metal sphere 2.0 m
in radius. The value of the Coulomb constant
is 8.99 × 109 N · m2 /C2 . 42 Chapter 23, section 13, Electric Field Lines
Field Dir by Insp 5
23:13, highSchool, multiple choice, < 1 min,
ﬁxed. 43 ﬁeld Enet is
1. aligned with the negative xaxis.
2. aligned with the negative y axis. Given rectangular insulators with uniformly charged distributions of equal magnitude as shown in the ﬁgure below, ﬁnd the
net electric ﬁeld at the origin. ++
++
++ ++
++
++ y 3. aligned with the positive y axis.
4. aligned with the positive xaxis.
5. nonzero and is not aligned with either
the x or y axis. x −−−−−−
In the ﬁgure above, at the origin, the net
ﬁeld Enet is 6. zero and the direction is undeﬁned.
Part 2 of 4
y
++++
x 1. aligned with the negative y axis.
2. aligned with the negative xaxis.
3. aligned with the positive y axis. ++++
In the ﬁgure above, at the origin, the net
ﬁeld Enet is 4. aligned with the positive xaxis.
1. zero and the direction is undeﬁned.
5. nonzero and is not aligned with either
the x or y axis.
6. zero and the direction is undeﬁned.
Field Directions by Inspectio
23:13, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 4
Given symmetrically placed rectangular insulators with uniformly charged distributions
of equal magnitude as shown in the ﬁgures below, ﬁnd the net electric ﬁeld at the origin in
the ﬁgures below.
y
++
++ −−
−− x
In the ﬁgure above, at the origin, the net 2. aligned with the negative xaxis.
3. aligned with the negative y axis.
4. aligned with the positive y axis.
5. aligned with the positive xaxis.
6. nonzero and is not aligned with either
the x or y axis.
Part 3 of 4 Chapter 23, section 13, Electric Field Lines 44 6. zero and the direction is undeﬁned. y
++++ Hewitt CP9 22 E35
23:13, highSchool, multiple choice, < 1 min,
ﬁxed.
x −−−−
In the ﬁgure above, at the origin, the net
ﬁeld Enet is
1. nonzero and is not aligned with either
the x or y axis.
2. aligned with the negative xaxis.
3. aligned with the negative y axis.
4. aligned with the positive y axis.
5. aligned with the positive xaxis.
6. zero and the direction is undeﬁned.
Part 4 of 4
y
+++++
+
−
+
−
+
−
+
−x
+
−
+++++
In the ﬁgure above, at the origin, the net
ﬁeld Enet is
1. aligned with the positive xaxis.
2. aligned with the negative xaxis.
3. aligned with the negative y axis.
4. aligned with the positive y axis.
5. nonzero and is not aligned with either
the x or y axis. A gravitational ﬁeld vector points toward
the Earth; an electric ﬁeld vector points toward an electron.
Why do electric ﬁeld vectors point away
from protons?
1. Protons have much larger mass.
2. Protons are positively charged.
3. Protons have more net charge than electrons.
4. Unlike electrons, protons will produce the
electric ﬁeld of their own.
5. None of these Chapter 23, section 15, A Point Charge in a Electric Field
Holt SF 17D 03
23:15, highSchool, numeric, > 1 min, normal.
Part 1 of 2
An electric ﬁeld of 20000 N/C is directed
along the positive xaxis.
The
charge
on
an
electron
is
−1.6 × 10−19 C.
What is the electric force on an electron in
this ﬁeld?
1. 20000 N, along the negative xaxis
2. 20000 N, along the positive xaxis
3. 3.2 × 10−15 N, along the positive xaxis
4. 3.2 × 10 −15 5. 5.12 × 10 10−9 N · m2 /C2 .
Find the magnitude of the electric force
acting on the electron.
Part 2 of 2
What is the magnitude of the electric ﬁeld
strength?
Holt SF 17Rev 49
23:15, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
What is the magnitude of the electric ﬁeld
that will balance the weight of an electron?
The acceleration of gravity is 9.81 m/s2 . N, along the negative xaxis 1. 5.58496 × 10−11 N/C downward N, along the negative xaxis 2. 5.58496 × 10−11 N/C upward N, along the positive xaxis 3. 1.02576 × 10−7 N/C downward −34 6. 5.12 × 10 45 −34 Part 2 of 2
What is the electric force on a proton in this
ﬁeld?
1. 20000 N, along the negative xaxis 4. 1.02576 × 10−7 N/C upward
5. 5.13158 × 10−8 N/C downward
6. 5.13158 × 10−8 N/C upward
7. None of these 2. 20000 N, along the positive xaxis
3. 3.2 × 10−15 N, along the positive xaxis
4. 3.2 × 10−15 N, along the negative xaxis
5. 5.12 × 10−34 N, along the negative xaxis
6. 5.12 × 10 −34 N, along the positive xaxis Holt SF 17Rev 41
23:15, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An electron moving through an electric
ﬁeld experiences an acceleration of 6300 ×
103 m/s2 .
The value of the Coulomb constant is 8.99 × 8. Unable to determine
Part 2 of 2
What is the magnitude of the electric ﬁeld
that will balance the weight of a proton?
1. 1.02576 × 10−7 N/C upward
2. 1.02576 × 10−7 N/C downward
3. 5.58496 × 10−11 N/C downward
4. 5.58496 × 10−11 N/C upward
5. 5.13158 × 10−8 N/C downward
6. 5.13158 × 10−8 N/C upward Chapter 23, section 15, A Point Charge in a Electric Field 46 7. None of these
8. Unable to determine cm Thunderstorms can have an electric ﬁeld of
up to 3.40 × 105 N/C.
What is the magnitude of the electric force
on an electron in such a ﬁeld? .4
10 Holt SF 17Rev 55
23:15, highSchool, numeric, > 1 min, wordingvariable. 9.81 m/s2 11000 N/C 38◦
2g a) Is the ball’s charge positive or negative?
1. positive 1. 340000 N/C 2. negative 2. 5.44 × 10−14 N 3. Unable to determine 3. 1.088 × 10−13 N
4. 680000 N
5. 1.36 × 10−14 N
Holt SF 17Rev 57
23:15, highSchool, numeric, > 1 min, wordingvariable.
An object with a net charge of 24 µC is
placed in a uniform electric ﬁeld of 610 N/C,
directed vertically.
The acceleration of gravity is 9.81 m/s2 .
What is the mass of this object if it ﬂoats
in this electric ﬁeld?
Holt SF 17Rev 60
23:15, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A very small 2 g plastic ball (carrying a
charge) is suspended by a 10.4 cm string in a
uniform electric ﬁeld of 11000 N/C, as shown.
The acceleration of gravity is 9.81 m/s2 . Part 2 of 2
b) If the ball is in equilibrium when the string
makes a 38 ◦ angle with the vertical as indicated, what is the net charge on the ball? Chapter 23, section 17, Motion of Charged Particles in a Uniform Electric Field
Holt SF 17Rev 51
23:17, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An electron and a proton are each placed
at rest in an external uniform electric ﬁeld of
520 N/C.
The mass of an electron is 9.109 × 10−31 kg
and its charge is −1.6 × 10−19 C .
a) Calculate the speed of the electron after
48 ns.
Part 2 of 2
b) Calculate the speed of the proton after 48
ns.
The mass of a proton is 1.673 × 10−27 kg
and the charge on a proton is 1.6 × 10−19 C .
Holt SF 17Rev 58
23:17, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A proton accelerates from rest in a uniform
electric ﬁeld of 640 N/C. At some time later,
its speed is 1.20 × 106 m/s.
The mass of a proton is 1.673 × 10−27 kg
and the charge of an electron 1.6 × 10−19 C .
a) What is the magnitude of the acceleration of the proton?
Part 2 of 4
b) How long does it take the proton to reach
this speed?
Part 3 of 4
c) How far has it moved in this time interval?
Part 4 of 4
d) What is its kinetic energy at the later
time?
Holt SF 17Rev 62
23:17, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3 47 If the electric ﬁeld strength is increased
to about 3.0 × 106 N/C, air “breaks down”
and loses its insulating quality. Under these
conditions, sparking results.
The mass of an electron is 9.109 × 10−31 kg
and its charge is −1.6 × 10−19 C.
a) How large an acceleration does an electron experience when the electron is placed in
such an electric ﬁeld?
Part 2 of 3
b) If the electron starts from rest when it is
placed in an electric ﬁeld under these conditions, in what distance does it acquire a speed
equal to 9.0 percent of the speed of light?
Part 3 of 3
c) How large an acceleration does a proton
experience when the proton is placed in such
an electric ﬁeld?
The mass of an proton is 1.673 × 10−27 kg
and the charge on an proton is 1.6 × 10−19 C.
Holt SF 17Rev 64
23:17, highSchool, numeric, > 1 min, wordingvariable.
An electron and a proton both start from
rest and from the same point in a uniform
electric ﬁeld of 370.0 N/C.
How far apart are they 1.00 µs after they
are released? Ignore the attraction between
the electron and the proton. (Imagine the
experiment performed with the proton only,
and then repeat with the electron only.)
Holt SF 17Rev 65
23:17, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An electron is accelerated by a constant
electric ﬁeld of 300.0 N/C.
a) Find the magnitude of the acceleration
of the electron.
Part 2 of 2
b) Find the electron’s speed after 1.00 × 10−8 s,
assuming it starts from rest. Chapter 23, section 17, Motion of Charged Particles in a Uniform Electric Field
Holt SF 17Rev 66
23:17, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A constant electric ﬁeld directed along the
positive xaxis has a strength of 2.0 × 103 N/C.
a) Find the electric force exerted on a proton by the ﬁeld.
Part 2 of 3
b) Find the acceleration of the proton.
Part 3 of 3
c) Find the time required for the proton to
reach a speed of 1.00 × 106 m/s, assuming it
starts from rest.
Holt SF 17Rev 68
23:17, highSchool, numeric, > 1 min, wordingvariable.
Each of the protons in a particle beam has
a kinetic energy of 3.25 × 10−15 J.
What electric ﬁeld strength will stop these
protons in a distance of 1.25 m? 48 Chapter 24, section 2, Gauss’s Law
Pt Charge and Charged Ring
24:02, highSchool, numeric, < 1 min, normal.
A point charge 6 µC is located at the center
of a uniform ring having linear charge density
17 µC/m and radius 3 m.
R λ q a
¡ ¡ Determine the total electric ﬂux through a
spherical surface centered at the point charge
and having radius R, where R < a, as shown. 49 Chapter 25, section 1, Electric Potential Energy
Holt SF 18A 01
25:01, highSchool, numeric, > 1 min, normal.
Two alpha particles (helium nuclei), each
consisting of two protons and two neutrons, have an electrical potential energy of
6.32 × 10−19 J .
Given: ke = 8.98755 × 109 N m2 /C2 , qp =
1.6021 × 10−19 C , and g = 9.8 m/s2 .
What is the distance between these particles at this time?
Holt SF 18A 02
25:01, highSchool, numeric, > 1 min, wordingvariable.
Two charges are located along the xaxis.
One has a charge of 6.4 µC, and the second
has a charge of −3.2 µC.
The Coulomb constant is ke =
8.98755 × 109 N m2 /C2 . The acceleration of
gravity is 9.81 m/s2 .
If the electrical potential energy associated
with the pair of charges is −4.1 × 10−2 J, what
is the distance between the charges?
Holt SF 18A 03
25:01, highSchool, numeric, > 1 min, normal.
Initially, both metal spheres are neutral.
In a charging process, 1 × 1013 electrons are
removed from one metal sphere and placed on
a second sphere. Then the electrical potential energy associated with the two spheres is
found to be −0.072 J .
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 and the charge on an electron
is 1.6 × 10−19 C .
What is the distance between the two
spheres?
Holt SF 18A 04
25:01, highSchool, numeric, > 1 min, wordingvariable.
A charge moves a distance of 2.0 cm in
the direction of a uniform electric ﬁeld having a magnitude of 215 N/C. The electrical 50 potential energy of the charge decreases by
13.7710 × 10−19 J as it moves.
Find the magnitude of the charge on the
moving particle. (Hint: The electrical potential energy depends on the distance moved in
the direction of the ﬁeld.) Chapter 25, section 2, Potential Diﬀerence and Electric Potential
Hewitt CP9 22 P06
25:02, highSchool, numeric, > 1 min, normal.
The potential diﬀerence between a storm
cloud and the ground is 1 × 108 V.
If a bolt carrying 2 C falls from a cloud to
Earth, what is the change of potential energy
of the charge?
Hewitt CP9 22 P09
25:02, highSchool, numeric, < 1 min, normal.
Part 1 of 2
An electric ﬁeld does 12 J of work on a
0.0001 C charge.
What is the voltage change?
Part 2 of 2
The same electric ﬁeld does 24 J of work on a
0.0002 C charge.
What is the voltage change?
Hewitt CP9 25 E33
25:02, highSchool, multiple choice, < 1 min,
ﬁxed.
The metal wing of an airplane acts like a
“wire” ﬂying through the Earth’s magnetic
ﬁeld. A voltage is induced between the wing
tips and a current ﬂows along the wing but
only for a short time.
Why does the current stop even though
the airplane keeps ﬂying through the Earth’s
ﬁeld?
1. We artiﬁcially exert a current to neutralize the current induced by the Earth’s magnetic ﬁeld.
2. The Earth’s magnetic ﬁeld in the high altitude is parallel to the wing of the airplane.
3. The airplane keeps ﬂying in a constant
velocity through the Earth’s ﬁeld.
4. A voltage diﬀerence is induced across the
wings of a moving airplane, which will produce only a momentary current. 51 5. None of these
Kinetic Energy 02
25:02, highSchool, numeric, > 1 min, normal.
Part 1 of 2
An object with a charge 1 C and a mass
0.2 kg accelerates from rest to a speed of
10 m/s.
Calculate the kinetic energy gained.
Part 2 of 2
Through how large a potential diﬀerence
did the object fall?
Potential Diﬀ
25:02, highSchool, numeric, > 1 min, normal.
The work needed to carry a 1 C charge from
point A to point B is 10 J.
Calculate the potential diﬀerence between
point A and B.
Potential Energy and Potential
25:02, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
Assume: An electric ﬁeld set up by an
unknown charge distribution.
U0 is the amount of work needed to bring a
point charge of charge q0 in from inﬁnity to a
point P .
If the charge q0 is returned to inﬁnity, how
much work W would it take to bring a new
charge q = 4 q0 from inﬁnity to point P ?
1. W = 8 U0
2. W = 4 U0
3. W = 2 U0
4. W = U0
5. W = U0
2 Chapter 25, section 2, Potential Diﬀerence and Electric Potential
U0
4
U0
7. W =
8
6. W = 8. W = 0
9. More information is needed.
10. The correct answer is not given.
Part 2 of 3
What is the electric potential V at point P ?
1. V = 4 U0 q0
2. V = U0 q0
3. V = U 0 q0
4 4. V = U0
4 U0
q0
U0
6. V =
q0
U0
7. V =
4 q0 5. V = 8. V = 0
9. More information is needed.
10. The correct answer is not given.
Part 3 of 3
If point P in Part 1 is at a distance a along
the xaxis, how much work W would it take to
bring the charge q0 to a point P at a distance
4 a along the xaxis?
1. W = 8 U0
2. W = 4 U0
3. W = 2 U0
4. W = U0 U0
2
U0
6. W =
4
U0
7. W =
8 5. W = 8. W = 0
9. More information is needed.
10. The correct answer is not given. 52 Chapter 25, section 3, Equipotential Surfaces
Equipotential Surfaces 01
25:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2 +Q −Q +
+
+
+
+
+
+ 53
−
−
−
−
−
−
− The dotted line or surface in the ﬁgure
above
1. is an equipotential line or surface. The dotted line or surface in the ﬁgure
above
1. is not an equipotential line or surface. 2. is not an equipotential line or surface.
3. cannot be determined from the information given. 2. is an equipotential line or surface.
Part 2 of 6
3. cannot be determined from the information given.
Part 2 of 2 +Q −Q +
+
+
+
+
+
+ −
−
−
−
−
−
− The dotted line or surface in the ﬁgure
above
The dotted line or surface in the ﬁgure
above
1. is an equipotential line or surface.
2. is not an equipotential line or surface.
3. cannot be determined from the information given.
Equipotential Surfaces
25:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 6 1. is not an equipotential line or surface.
2. is an equipotential line or surface.
3. cannot be determined from the information given.
Part 3 of 6 +Q The dotted line or surface in the ﬁgure
above
1. is not an equipotential line or surface. Chapter 25, section 3, Equipotential Surfaces 54 2. is an equipotential line or surface.
1. is an equipotential line or surface.
3. cannot be determined from the information given. 3. cannot be determined from the information given. Part 4 of 6 +Q The dotted line or surface in the ﬁgure
above
1. is an equipotential line or surface.
2. is not an equipotential line or surface.
3. cannot be determined from the information given.
Part 5 of 6 +Q −Q The dotted line or surface in the ﬁgure
above
1. is not an equipotential line or surface.
2. is an equipotential line or surface.
3. cannot be determined from the information given.
Part 6 of 6 +Q 2. is not an equipotential line or surface. −Q The dotted line or surface in the ﬁgure
above Chapter 25, section 4, Calculating the Potential from the Field
Holt SF 18Rev 12
25:04, highSchool, numeric, > 1 min, normal.
The magnitude of a uniform electric
ﬁeld between the two plates is about
1.7 × 106 N/C.
If the distance between these plates is
1.5 cm, ﬁnd the potential diﬀerence between
the plates.
Holt SF 18Rev 13
25:04, highSchool, numeric, > 1 min, wordingvariable.
A force of 4.30 × 10−2 N is needed to move
a charge of 56.0 µC a distance of 20.0 cm in
the direction of a uniform electric ﬁeld.
What is the potential diﬀerence that will
provide this force? 55 Chapter 25, section 5, Potential & Energy: Point Charges 56 b) Determine the charge.
Energy gained from A to B
25:05, highSchool, numeric, < 1 min, normal.
A proton is released from rest in a uniform electric ﬁeld of magnitude 80000 V/m
directed along the positive x axis. The proton undergoes a displacement of 0.5 m in the
direction of the electric ﬁeld as shown in the
ﬁgure.
80000 V/m
+
−
+
−
+
−
+
−
+
−
+
−
+ vA = 0 v0
−
++
−
+
−
0. 5 m
+
−
B−
+A
+
−
+
−
Apply the principle of energy conservation to ﬁnd the amount of the kinetic energy
gained after it has moved 0.5 m. Holt SF 18Rev 36
25:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A proton is accelerated from rest through a
potential diﬀerence of 25700 V.
a) What is the kinetic energy of this proton
after this acceleration?
Part 2 of 2
b) What is the speed of the proton after this
acceleration?
Holt SF 18Rev 37
25:05, highSchool, numeric, > 1 min, wordingvariable.
A proton is accelerated from rest through a
potential diﬀerence of 120 V.
Calculate the ﬁnal speed of this proton. Holt SF 18B 01
25:05, highSchool, numeric, > 1 min, normal. Holt SF 18Rev 42
25:05, highSchool, numeric, > 1 min, wordingvariable. The Coulomb constant is 8.98755 ×
109 N m2 /C2 and the acceleration of gravity
is 9.81 m/s2 .
Find the potential diﬀerence between a
point inﬁnitely far away and a point 1 cm
from a proton. An ion is displaced through a potential diﬀerence of 60.0 V and experiences
an increase of electrical potential energy of
192.262 × 10−17 J.
Calculate the charge on the ion. Holt SF 18Rev 29
25:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
At some distance from a point charge, the
electric potential is 600.0 V and the magnitude of the electric ﬁeld is 200.0 N/C.
The value of the Coulomb constant is
8.98755 × 109 N · m2 /C2 and the acceleration
of gravity is 9.81 m/s2 .
a) Determine the distance from the charge.
Part 2 of 2 Holt SF 18Rev 44
25:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A proton is accelerated through a potential
diﬀerence of 4.5 × 106 V.
a) How much kinetic energy has the proton
acquired?
Part 2 of 2
b) If the proton started at rest, how fast is it
moving?
Holt SF 18Rev 45 Chapter 25, section 5, Potential & Energy: Point Charges
25:05, highSchool, numeric, > 1 min, wordingvariable.
A positron (a particle with a charge of +e
and a mass equal to that of an electron) that
is accelerated from rest between two points at
a ﬁxed potential diﬀerence acquires a speed of
9.0 × 107 m/s.
What speed is achieved by a proton accelerated from rest between the same two points?
(Disregard relativistic eﬀects.)
Holt SF 18Rev 46
25:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The speed of light is 3.00 × 108 m/s.
a) Through what potential diﬀerence would
an electron starting from rest need to accelerate to achieve a speed of 60.0% of light?
(Disregard relativistic eﬀects.)
Part 2 of 2
b) Through what potential diﬀerence would a
positron (a particle with a charge of +e and
a mass equal to that of an electron) starting
from rest need to accelerate to achieve a speed
of 60.0% of light? (Disregard relativistic effects.)
Holt SF 18Rev 47
25:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An electron moves from one plate of a capacitor to another, through a potential diﬀerence of 2200 V.
a) Find the speed with which the electron
strikes the positive plate.
Part 2 of 2
b) If a proton moves from the positive plate to
the negative plate, ﬁnd the speed with which
the proton strikes the negative plate. 57 Chapter 25, section 6, Potential & Energy: Systems of Point Charges 58 Add a Charge to Four 02
25:06, highSchool, numeric, > 1 min, normal. side a is 0.4 m, the magnitude of the electric
force on the charge q when it is placed at the
center is Part 1 of 3
Four charges are placed at the corners of
a square of side a, with Q1 = Q2 = −q ,
Q3 = Q4 = +q , where q is positive. Initially
there is no charge at the center of the square.
Q 2 = −q
Q 3 = +q Part 3 of 3
The magnitude of the total electrostatic
energy of the ﬁnal 5 charge system is given by
(Hint: It may be useful to consider the
symmetry property of the charge distribution
which leads to cancellations among several
terms). Qi = 0
a
Q f = +q Q 1 = −q Q 4 = +q Find the work required to bring the charge
q from inﬁnity and place it at the center of
the square. 2. U
3. U
4. U
5. U 1. W = 0
2. W =
3. W =
4. W =
5. W =
6. W =
7. W =
8. W =
9. W =
10. W = √ k q2
2 2.
a
√ k q2
=2
.
a
k q2
=2 2 .
a
√ k q2
= 2 2.
a
√ k q2
=2 2 2 .
a
2
kq
=4
.
a
k q2
=2
.
a
k q2
=4 2 .
a
√ k q2
=4 2
.
a
k q2
=8 2 .
a 1. U = 4 4 k q2
a2
2 k q2
a2
−2 k q 2
a2
−4 k q 2
a2
4 k q2
a
2 k q2
a
−2 k q 2
a
−4 k q 2
a
8 k q2
a2 Part 2 of 3
If the charge of q is 5 µC and the length of 6. U
7. U
8. U
9. U
10. U Add a Charge to Four 3
25:06, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Four charges are placed at the corners of a
square of side a, with q1 = q2 = −q , q3 = q4 =
+q , where q is positive. Initially there is no
charge at the center of the square. Chapter 25, section 6, Potential & Energy: Systems of Point Charges
q 2 = −q q 3 = +q 4. U
5. U q 1 = −q q 4 = +q Find the work required to bring the charge
q from inﬁnity and place it at the center of
the square.
1. W = 0
2. W =
3. W =
4. W =
5. W =
6. W =
7. W =
8. W =
9. W =
10. W = 4 k q2
a2
2 k q2
a2
−2 k q 2
a2
−4 k q 2
a2
4 k q2
a
2 k q2
a
−2 k q 2
a
−4 k q 2
a
8 k q2
a2 Part 2 of 2
The magnitude of the total electrostatic energy of the ﬁnal 5 charge system is given by
(Hint: It may be useful to consider the
symmetry property of the charge distribution
which leads to cancellations among several
terms.)
√ k q2
1. U = 4 2 2 .
a √ k q2
2
.
a
k q2
=2 2 .
a
√ k q2
= 2 2.
a
√ k q2
=2 2 2 .
a
2
kq
.
=4
a
k q2
.
=2
a
k q2
=4 2 .
a
√ k q2
.
=4 2
a
k q2
=8 2 .
a 2. U =
3. U q 59 6. U
7. U
8. U
9. U
10. U Add a Charge to Four JMS
25:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Four charges are placed at the corners of a
square of side a, with q1 = q2 = −q , q3 = q4 =
+q , where q is positive. Initially there is no
charge at the center of the square.
q 2 = −q
q3 = +q q q 1 = −q q4 = +q Find the work required to bring the charge
q from inﬁnity and place it at the center of
the square.
1. W = 0
2. W = 4 k q2
a2 Chapter 25, section 6, Potential & Energy: Systems of Point Charges
3. W =
4. W =
5. W =
6. W =
7. W =
8. W =
9. W =
10. W = 2 k q2
a2
−2 k q 2
a2
−4 k q 2
a2
4 k q2
a
2 k q2
a
−2 k q 2
a
−4 k q 2
a
8 k q2
a2 6. U = 10. None of these.
Holt SF 18B 02
25:06, highSchool, numeric, > 1 min, normal. 2 +Q 2 +Q What is the electric potential energy of the
following system of charges. 2. U =
3. U = −k Q 2 k Q2
3
−k Q 2
5. U =
3
4. U = 2 −k Q 2
8. U =
2
k Q2
9. U =
2 A system of charges are shown in the ﬁgure.
−Q k Q2 k Q2 7. U = k Q2 Energy of a System of Charges
25:06, highSchool, multiple choice, < 1 min,
ﬁxed. 1. U = 0 60 Two point charges of magnitude 5 nC and
−3 nC are separated by 35 cm .
The Coulomb constant is 8.98755 ×
109 N m2 /C2 and the acceleration of gravity
is 9.81 m/s2 .
What is the potential diﬀerence between a
point inﬁnitely far away and a point midway
between the charges?
Holt SF 18B 03
25:06, highSchool, numeric, > 1 min, normal.
Four particles with charges of 5 µC, 3 µC,
3 µC and −5 µC are placed at the corners of
a “2 m × 2 m” square.
The acceleration of gravity is 9.81 m/s2
and
the
Coulomb
constant
is
8.98755 × 109 N m2 /C2 .
Determine the potential diﬀerence between
the center of the square and inﬁnity.
Holt SF 18Rev 04
25:06, highSchool, numeric, > 1 min, wordingvariable.
A point charge of 9.00 × 10−9 C is located
at the origin of a coordinate system. A positive charge of 3.00 × 10−9 C is brought in from
inﬁnity to a point such that the electrical potential energy associated with the two charges
is 8.09 × 10−7 J.
The Coulomb constant is 8.98755 ×
109 N m2 /C2 and the acceleration of gravity
is 9.81 m/s2 .
How far apart are the charges at this Chapter 25, section 6, Potential & Energy: Systems of Point Charges 61 time? 8.0 µC P cm
4.0 Consider charges placed at the corners of a
rectangle:
Let: ke = 8.98755 × 109 N m2 /C2 and g =
9. 8 m /s 2 . The three charges shown in the ﬁgure are
located at the vertices of an isosceles triangle.
The Coulomb constant is 8.98755 ×
109 N · m2 /C2 and the acceleration of gravity is 9.8 m/s2 .
4.0 × 10−9 C
+ 4.0
cm Holt SF 18Rev 14
25:06, highSchool, numeric, > 1 min, wordingvariable. + 0.20 m
0.35 m
− − −8.0 µC −12 µC 5.0 × 10−9 C − − 5.0 × 10−9 C 2.0 cm
Calculate the electric potential at the midpoint of the base if the magnitude of the positive charge is 4.0 × 10−9 C and the magnitude
of the negative charges are 5.0 × 10−9 C. Find the electric potential at point P due
to the grouping of charges at the other corners
of the rectangle. Holt SF 18Rev 40
25:06, highSchool, numeric, > 1 min, wordingvariable. Holt SF 18Rev 31
25:06, highSchool, numeric, > 1 min, wordingvariable. Part 1 of 2
A charge of −3.00 × 10−9 C is at the origin
of a coordinate system, and a charge of 8.00 ×
10−9 C is on the xaxis at 2.00 m. There are
two locations on the xaxis, where the electric
potential is zero.
a) Find the location of the point between
the charges. Three charges are situated at three corners
of a rectangle, as shown.
The Coulomb constant is 8.98755 ×
9
10 N · m2 /C2 and the acceleration of gravity is 9.8 m/s2 . Part 2 of 2
b) Find the location of the point to the left of
the y − axis. 8.0 µC
+
6.0 cm
3.0 cm
+
2.0 µC +
4.0 µC How much electrical potential energy would
be expended in moving the 8.0 µC charge to
inﬁnity?
Holt SF 18Rev 39
25:06, highSchool, numeric, > 1 min, wordingvariable. Three Point Charges 04
25:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Three point charges −q , 2q and q are located at the corners of an equilateral triangle
of side a. Chapter 25, section 6, Potential & Energy: Systems of Point Charges
−2 q 4. U
5. U
6. U
7. U
8. U q2
= −k
a
q2
= 2k
a
q2
= −2 k
a
2
q
= 3k
a
q2
= −3 k
a
2
q
= 4k
a Part 2 of 2
The total electric energy stored in the triangular system is L
Aq 2. U = 0 1. WB =
2. WB =
3. WB =
4. WB =
5. WB = 2. U = 0 6. WB = q2
a
q2
4. U = 2 k
a
q2
5. U = −2 k
a 1 L Now leave q1 ,q3 , and q4 ﬁxed and bring q2
from inﬁnity to point B .
The work WB required is given by q2
1. U = k
a 3. U = −k q2 B q2
a Part 1 of 2
Four point charges are placed at the four
corners of a square. Each side of the square
has length L. Four point charges are q1 =
q2 = q 3 = q 4 = q .
q4
q3 P
+q
−q
Remove −q to inﬁnity. What is the work
done (against the electric force due to 2q and
q ) in bringing in charge −q from the inﬁnity to
the point bottom right vertex of the triangle. Work and potential in a square
25:06, highSchool, multiple choice, > 1 min,
normal. a ˆ
ı 60◦ 3. U q2
a
q2
7. U = −3 k
a
q2
8. U = 4 k
a
6. U = 3 k ˆ 1. U = k 62 7. WB =
8. WB =
9. WB = kq
L2
k q2
L
k q2
2L
k q2
√
2 L2
k q2
L2
k q2
2 L2
kq
√
2 L2
k q2
√
2L
kq
2 L2 Chapter 25, section 6, Potential & Energy: Systems of Point Charges
1 k q2
10. WB = (2 + √ )
2L
Part 2 of 2
Given q1 = q2 = 1 µC, L = 0.2 cm and
k = 9 × 109 N · m2 /C2 , ﬁnd the potential at
B due to the charge q1 alone. 63 Chapter 25, section 7, Potential & Energy: Electric Dipoles
Holt SF 18Rev 05
25:07, highSchool, numeric, > 1 min, wordingvariable.
An electron that is initially 55 cm away
from a proton is displaced to another point.
The Coulomb constant is 8.98755 ×
109 N m2 /C2 and the acceleration of gravity
is 9.8 m/s2 .
If the change in the electrical potential
energy as a result of this movement is
2.1 × 10−28 J, what is the ﬁnal distance between the electron and the proton? 64 Chapter 25, section 8, Potential & Energy: Continuous Charge Distributions
Holt SF 18Rev 41
25:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A pair of oppositely charged parallel plates
are separated by a distance of 5.0 cm with
a potential diﬀerence of 550 V between the
plates. A proton is released from rest at
the positive plate at the same time that an
electron is released from rest at the negative
plate. Disregard any interaction between the
proton and the electron.
How long does it take for the paths of the
proton and the electron to cross?
Part 2 of 4
How fast will the electron be traveling when
the particles’ paths cross?
Part 3 of 4
How fast will the proton be traveling when
the particles’ paths cross?
Part 4 of 4
How much time will elapse before the proton
reaches the opposite plate? 65 Chapter 25, section 9, Potential & Energy: Charged Conductor
Conducting Spheres 07
25:09, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 2
Consider two “solid” conducting spheres
with radii r1 = 4 R and r2 = 7 R ; i.e., 7R
7
r2
=
=.
r1
4R
4
The two spheres are separated by a large
distance so that the ﬁeld and the potential at
the surface of sphere #1 only depends on the
charge on #1 and the corresponding quantities on #2 only depend on the charge on
#2.
Place an equal amount of charge on both
spheres, q1 = q2 = Q . r2 9. 1.
2.
3.
4.
5. 7. q1 #1 q2 8. #2 After the electrostatic equilibrium on each
sphere has been established, what is the ratio
V2
of the potentials
at the “centers” of the
V1
two solid conducting spheres?
1.
2.
3.
4.
5.
6.
7.
8. V2
V1
V2
V1
V2
V1
V2
V1
V2
V1
V2
V1
V2
V1
V2
V1 =
=
=
=
=
=
=
= 4
7
7
4
7
2
7
8
16
49
49
16
49
8
49
32 V2
=1
V1 Part 2 of 2
E2
What is the ratio of the electric ﬁelds
at
E1
the “surfaces” of the two spheres? 6. r1 66 9. E2
E1
E2
E1
E2
E1
E2
E1
E2
E1
E2
E1
E2
E1
E2
E1
E2
E1 =
=
=
=
=
=
=
= 16
49
49
16
49
8
49
32
4
7
7
4
7
2
7
8 =1 Chapter 25, section 10, Calculating the Field from the Potential
Holt SF 18Rev 32
25:10, highSchool, numeric, > 1 min, wordingvariable.
A 12 V battery is connected across two
parallel metal plates separated by 0.30 cm.
Find the magnitude of the electric ﬁeld. 67 Chapter 25, section 14, The Van de Graaﬀ Generator and Other Applications 68 strength at the surface of the dome.
Hewitt CP9 22 E44
25:14, highSchool, multiple choice, < 1 min,
ﬁxed.
Would you feel any electrical eﬀects if you
were inside the charged sphere of a van de
Graaﬀ generator? Why or why not?
1. Yes; the electric ﬁeld is very strong inside
the van de Graﬀ generator.
2. Yes; the electric ﬁeld exists both inside
and outside of the generator.
3. No; the inside of the generator has zero
charge and thus no electric ﬁeld.
4. No; although there are charges inside the
generator, the net charge is zero.
5. More information is needed.
6. None of these
Hewitt CP9 22 P07
25:14, highSchool, numeric, > 1 min, normal.
An energy of 0.1 J is stored in the metal
ball on top of a Van de Graaﬀ machine. A
spark carrying 1 µC discharges the ball.
What was the ball’s potential relative to
ground?
Holt SF 17Rev 52
25:14, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
The dome of a Van de Graaﬀ generator
receives a charge of 2.0 × 10−4 C. The radius
of the dome is 1.0 m.
The value of the Coulomb constant is
8.98755 × 109 N · m2 /C2 .
Find the magnitude of the electric ﬁeld
strength inside the dome.
Part 2 of 3
Find the magnitude of the electric ﬁeld Part 3 of 3
Find the magnitude of the electric ﬁeld
strength at a distance of 4.0 m from the center
of the dome.
Holt SF 17Rev 54
25:14, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Given : mp = 1.673 × 10−27 kg
qp = 1.60218 × 10 −19 and C. A Van de Graaﬀ generator is charged so that
the electric ﬁeld at its surface is 33000 N/C .
What is the magnitude of the electric force
on a proton released at the surface of the
generator?
Part 2 of 2
Find the proton’s acceleration at this instant.
The mass of a proton is given to be
1.673 × 10−27 kg. Chapter 26, section 1, Deﬁnition of Capacitance
Holt SF 18C 03
26:01, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A capacitor has a capacitance of 2 pF.
a) What potential diﬀerence would be required to store 18 pC?
Part 2 of 2
b) How much charge is stored when the potential diﬀerence is 2.5 V?
Holt SF 18Rev 43
26:01, highSchool, numeric, > 1 min, wordingvariable.
A potential diﬀerence of 100.0 V exists
across the plates of a capacitor when the
charge on each plate is 400.0 µC.
What is the capacitance? 69 Chapter 26, section 2, Calculation of Capacitance 70 Holt SF 18C 04
26:02, highSchool, numeric, > 1 min, wordingvariable. Holt SF 18Rev 33
26:02, highSchool, numeric, > 1 min, wordingvariable. You are asked to design a parallelplate
capacitor having a capacitance of 1.00 F and
a plate separation of 1.00 mm.
Calculate the required surface area of each
plate. Part 1 of 2
A parallelplate capacitor has an area of
5.00 cm2 and the plates are separated by
1.00 mm. The capacitor stores a charge of
400.0 pC.
The permittivity of a vacuum is
8.85419 × 10−12 C2 /N · m2 .
a) What is the potential diﬀerence across
the plates of the capacitor? Holt SF 18Rev 24
26:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The potential diﬀerence between a pair of
oppositely charged parallel plates is 400 V.
a) If the spacing between the plates is doubled without altering the charge on the plates,
what is the new potential diﬀerence between
the plates?
Part 2 of 2
b) If the plate spacing is doubled while the
potential diﬀerence between the plates is kept
constant, what is the ratio of the ﬁnal charge
on one of the plates to the original charge?
Holt SF 18Rev 26
26:02, highSchool, numeric, > 1 min, wordingvariable.
A 12.0 V battery is connected to a 6.0 pF
parallelplate capacitor.
What is the magnitude of the charge on
each plate?
Holt SF 18Rev 30
26:02, highSchool, numeric, > 1 min, normal.
A circular parallelplate capacitor with a
spacing of 3 mm is charged to produce
a uniform electric ﬁeld with a strength of
3 × 106 N/C.
The permittivity of vacuum is 8.85 ×
−12 2
10
C /N · m 2 .
What plate radius is required if the stored
charge is −1 µC? Part 2 of 2
b) What is the magnitude of the uniform electric ﬁeld in the region that is located between
the plates?
Holt SF 18Rev 34
26:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A parallelplate capacitor has a plate
area of 175 cm2 and a plate separation of
0.0400 mm.
The permittivity of a vacuum is 8.85419 ×
−12 2
10
C /N · m 2 .
a) Determine the capacitance.
Part 2 of 2
b) Determine the potential diﬀerence when
the charge on the capacitor is 500.0 pC.
Holt SF 18Rev 48
26:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Each plate on a 3750 pF capacitor carries a
charge with a magnitude of 1.75 × 10−8 C.
a) What is the potential diﬀerence across
the plates when the capacitor has been fully
charged?
Part 2 of 2
b) If the plates are 6.50 × 10−4 m apart, what Chapter 26, section 2, Calculation of Capacitance
is the magnitude of the electric ﬁeld between
the two plates? 71 Chapter 26, section 3, Combinations of Capacitors 72 26:03, highSchool, numeric, > 1 min, normal. 12 µF 41 µF 34 µF Part 1 of 3
Consider the group of capacitors shown in
the ﬁgure. Consider the capacitor circuit
19 µF Capacitor Circuit 04 shortened
26:03, highSchool, numeric, > 1 min, normal. 2. 4 µ F
5 µF
a
b 8. 3 µ F 2. 2 µ F
c
d 12 V Find the equivalent capacitance between
points a and d.
Part 2 of 3
Determine the charge on the 5 µF capacitor
on the lefthand side of the circuit.
Part 3 of 3
Determine the charge on the 2.4 µF capacitor
at the top center part of the circuit.
Capacitor Circuit 04 shortest
26:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Consider the group of capacitors shown in
the ﬁgure.
2. 4 µ F
5 µF
a
b 8. 3 µ F 2. 2 µ F
c
d 12 V Find the equivalent capacitance between
points a and d.
Part 2 of 2
Determine the charge on the 2.4 µF capacitor
at the top center part of the circuit.
Capacitor Circuit 07 30 V
What is the eﬀective capacitance of the
circuit?
Capacitor Circuit 09
26:03, highSchool, multiple choice, > 1 min,
ﬁxed.
Consider the group of capacitors shown in
the ﬁgure.
C
a C
b C c 2C
d EB Find the equivalent capacitance Cad between points a and d.
1. Cad =
2. Cad =
3. Cad =
4. Cad =
5. Cad =
6. Cad = 1
C
2
2
C
5
3
C
5
2
C
3
3
C
4
1
C
3 7. Cad = 2 C
8. Cad = 3 C Chapter 26, section 3, Combinations of Capacitors
capacitor between points a and c. 9. Cad = 4 C
10. Cad = 5 C
Four Capacitors 01
26:03, highSchool, numeric, > 1 min, normal.
Part 1 of 8
In the ﬁgure below consider the case where
switch S1 is closed and switch S2 is open.
c
30
F
µF
0µ
1
a 20 µF 50 V S2 S1 Part 2 of 8
Find the charge on the 20 µF lowerleft capacitor between points a and d.
Part 3 of 8
Find the charge on the 30 µF upperright
capacitor between points c and b.
Part 4 of 8
Find the charge on the 40 µF lowerright capacitor between points d and b.
Part 5 of 8
Now consider the case where switch S2 is also
closed.
c
30
µF
µF
10 50 V 20 µF S2 d 40 Part 7 of 8
Find the charge on the 30 µF upperright
capacitor between points c and b.
Part 8 of 8
Find the charge on the 40 µF lowerright capacitor between points d and b.
Four Capacitors 01 shortened
26:03, highSchool, numeric, > 1 min, normal. 4
d Part 6 of 8
Find the charge on the 20 µF lowerleft capacitor between points a and d. b F
0µ Find the charge on the 10 µF upperleft
capacitor between points a and c. a 73 Part 1 of 2
In the ﬁgure below consider the case where
switch S1 is closed and switch S2 is open.
c
30
µF
µF
0
1
a 20 µF 50 V S2 4 Find the charge on the 10 µF upperleft
capacitor between points a and c.
Part 2 of 2
Now consider the case where switch S2 is also
closed.
c
30
µF
µF
10
a 50 V
S1 Find the charge on the 10 µF upperleft S1 d 20 µF S2 b F
0µ 4 b µF b F
0µ d S1 Find the charge on the 10 µF upperleft
capacitor between points a and c. Chapter 26, section 3, Combinations of Capacitors
Four Capacitors 02 v2
26:03, highSchool, numeric, > 1 min, wordingvariable. 3 µF
a Part 1 of 3
The capacitors in the ﬁgure are initially uncharged and are connected as in the diagram.
Then switch S1 closed and switch S2 is left
open.
c
57
F
µF
0µ
7
1
a 57 µF 113 V S2 b µF
70
1
S1 d After a long wait, what is the magnitude of
the potential diﬀerence Vcd ≡ Vc − Vd ?
Part 2 of 3
The potential diﬀerence Vcd is
1. positive.
2. negative.
Part 3 of 3
The switch S2 is closed.
c
57
F
µF
0µ
7
1
a 113 V 57 µF S2 d b µF
70
1
S1 After closing the switch S2 , what is the
potential diﬀerence Vad ?
Voltage in capacitor network
26:03, highSchool, numeric, > 1 min, normal.
A capacitor network is shown in the following ﬁgure. 74
4 µF 10 µF b 10 V What is the voltage across the 4 µF upper
righthand capacitor? Chapter 26, section 4, Energy Stored in a Charged Capacitor +Q A
E The total energy stored in the capacitor is
given by 2. U =
3. U =
4. U =
5. U =
6. U =
7. U =
8. U = 29 µF −Q A 1. U = 35 µF d Part 1 of 2
A capacitor network is shown below.
33 µF Part 1 of 2
Consider an airﬁlled parallel plate capacitor with plate area A and gap width d. The
plate charge is Q. Circuit Energy e1
26:04, highSchool, numeric, > 1 min, wordingvariable. 31 µF Charge with battery connected 01
26:04, highSchool, multiple choice, > 1 min,
normal. 75 Q2
.
2 0Ad
Q2
.
0Ad
Q2 d
.
2 0A
QA
.
0d
Q
.
2 0Ad
Qd
.
0A
Q
.
0Ad
Q2 A
.
0d Part 2 of 2
With the battery connected, ﬁll the gap by a
slab with the dielectric constant κ.
Given: E = 30 V, κ = 2, d = 0.1 mm, and
A = 10 cm2 , 0 = 8.85 × 10−12 C 2 /N · m2 , ﬁnd
the electric charge on the plate. 30 V
What is the eﬀective capacitance of the
circuit?
Part 2 of 2
For the circuit above what is the total energy
stored by the 29 µF capacitor on the righthand side of the circuit? (Hint: Notice that
the equivalent capacitance of the 31 µF and
33 µF capacitors is equal the the equivalent
capacitance of the 35 µF and 29 µF capacitors.)
Energy in Par Plate Capacitor
26:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider a parallel plate capacitor with
plate area A and a distance d between plates.
The capacitor has a charge Q on the top plate
and charge −Q on the bottom plate.
How much electrostatic energy is stored in
this capacitor?
1. U =
2. U =
3. U =
4. U =
5. U = Qd
A
A
Qd
Qd
0A
Q2 d
2 0A
A0
Qd Chapter 26, section 4, Energy Stored in a Charged Capacitor
6. U =
7. U =
8. U =
9. U =
10. U = Q 2 d2
2 0 A2
A2 0
Q 2 d2
A2 2
0
Q 2 d2
Q 2 d2
a2
A2
Q 2 d2 Hewitt CP9 22 E43
26:04, highSchool, multiple choice, < 1 min,
ﬁxed.
In order to store more energy in a parallelplate capacitor whose plates diﬀer by a ﬁxed
voltage, what change would you make in the
plates?
1. Move the plates farther apart.
2. Decrease the area of the plates by half.
3. Insert a nonconducting material between
the plates.
4. Replace the plates with ones made of
more conductive material.
5. Replace the plates with ones made of less
conductive material.
6. None of these
Holt SF 18C 01
26:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A 4.00 µF capacitor is connected to a
12.0 V battery.
a) What is the charge on each plate of the
capacitor?
Part 2 of 2
b) If this same capacitor is connected to a
1.50 V battery, how much electrical potential 76 energy is stored?
Holt SF 18C 02
26:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A parallelplate capacitor has a charge of
6.0 µC when charged by a potential diﬀerence
of 1.25 V .
a) Find its capacitance.
Part 2 of 2
b) How much electrical potential energy is
stored when this capacitor is connected to a
1.50 V battery?
Holt SF 18Rev 27
26:04, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A parallelplate capacitor has a capacitance
of 0.2 µF and is to be operated at 6500 V.
a) Calculate the charge stored.
Part 2 of 2
b) What is the electrical potential energy
stored in the capacitor at the operating potential diﬀerence?
Holt SF 18Rev 28
26:04, highSchool, numeric, > 1 min, normal.
Two devices with capacitances of 25 µF and
5 µF are each charged with separate 120 V
power supplies.
Calculate the total energy stored in the two
capacitors.
Holt SF 18Rev 38
26:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A pair of oppositely charged parallel plates
are separated by 5.33 mm. A potential diﬀerence of 600.0 V exists between the plates.
a) What is the magnitude of the electric
ﬁeld strength in the region that is located Chapter 26, section 4, Energy Stored in a Charged Capacitor
between the plates?
Part 2 of 3
b) What is the magnitude of the force on
an electron that is in the region between the
plates at a point that is exactly 2.9 mm from
the positive plate?
Part 3 of 3
The electron is moved to the negative plate
from an initial position 2.9 mm from the positive plate.
c) What is the change in electrical potential
energy due to the movement of this electron?
Holt SF 18Rev 49
26:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 5
A parallelplate capacitor is made of two
circular plates, each with a diameter of
2.50 × 10−3 m. The plates of this capacitor are separated by a space of 1.40 × 10−4 m.
The permittivity of a vacuum is 8.85419 ×
10−12 C2 /N · m2 .
a) Assuming that the capacitor is operating
in a vacuum, ﬁnd the capacitance for this
arrangement.
Part 2 of 5
b) How much charge will be stored on each
plate of this capacitor when it is connected
across a potential diﬀerence of 0.120 V?
Part 3 of 5
c) What is the electrical potential energy stored in this capacitor when it is
fully charged by the potential diﬀerence of
0.120 V?
Part 4 of 5
d) What is the potential diﬀerence between a
point midway between the plates and a point
that is 1.10 × 10−4 m from one of the plates?
Part 5 of 5
e) If the potential diﬀerence of 0.120 V is
removed from the circuit and if the circuit is 77 allowed to discharge until the charge on the
plates has decreased to 70.7 percent of its
fully charged value, what will the potential
diﬀerence across the capacitor be? Chapter 26, section 5, Capacitors with Dielectrics
Capacitor Comparison e1
26:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider the setup shown, where a capacitor with a capacitance C is connected to a
battery with emf V and negligible internal
resistance.
Before the insertion of the dielectric slab
with dielectric constant κ, the energy density
within the gap is u.
Now, keeping the battery connected, insert
the dielectric, which ﬁlls the gap completely. ducting sphere with charge Q.
Hint: Use the capacitance formula for
a spherical capacitor which consists of two
spherical shells. Take the inner sphere to
have a radius a and the outer shell to have an
inﬁnite radius.
1. U =
2. U =
3. U =
4. U = d V C
Determine the energy density u within the
gap in the presence of the dielectric.
1. u = u κ2
2. u = u κ
3. u = u
κ 4. u = u
u
κ2
u
6. u = √
κ
√
7. u = u κ 5. U =
6. U =
7. U =
8. U = 1. U =
2. U =
3. U =
4. U = uκ
2
u
10. u =
2κ 6. U = Capacitor Energy v2
26:05, highSchool, numeric, < 1 min, ﬁxed. 7. U = 9. u = Part 1 of 4
Determine the total energy stored in a con Q2 π
8 0a
Q2
4π 0a
Q2
16 π 0 a
Q
8π 0a
Q2
8 π 0 a2
Q2 a
4π 0
Q2
a
Q2
8π 0a Part 2 of 4
Find the energy stored in a capacitor of charge
Q ﬁlled with a dielectric with dielectric constant κ. 5. u = 8. u = 2 u κ 78 5. U = 8. U = Q
2κC
Q2
κC
Q2
2 (κ − 1) C
Q2
2C
Q
4κC
Q2
3κC
Q2
3 (κ − 1) C
Q2
3C Chapter 26, section 5, Capacitors with Dielectrics
Q2
9. U =
2κC
Part 3 of 4
Work = Uf − Ui , where “i” is the initial state
where there is a slab in the gap and “f” is the
ﬁnal state where there is no slab in the gap.
Find the work done in pulling a dielectric
slab of dielectric constant κ from the gap of a
parallel plate capacitor of plate charge Q and
capacitance C .
1. Wif =
2. Wif =
3. Wif =
4. Wif =
5. Wif =
6. Wif =
7. Wif =
8. Wif =
9. Wif = Q2
2κC
Q2
1
κ−
2C
κ
2
Q
2C
Q2
(1 − κ)
2C
Q2 1
−1
2C κ
Q2
1
κ+
2C
κ
Q2
1
1−
2C
κ
2
Q
(1 − κ)
2κC
Q2
5κC Part 4 of 4
Consider a capacitor which is connected to a
battery with an emf V . Denote the energy
stored in the capacitor in the absence of a
dielectric, with dielectric constant κ, to be U
and in the presence of the dielectric to be U .
U
Find the ratio
as the potential across
U
the plates is held at a constant value by the
battery.
U
1
1.
=
U
κ
U
2.
=1
U 3.
4.
5.
6.
7.
8. U
U
U
U
U
U
U
U
U
U
U
U = 79 1
2 =κ
1
2κ
√
=2
= = 1
3 = 2κ Charge with battery connected
26:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Consider an airﬁlled parallel plate capacitor with plate area A and gap width d. The
plate charge is Q.
d
+Q −Q A A
E The total energy stored in the capacitor is
given by
1. U =
2. U =
3. U =
4. U =
5. U = Q2
.
2 0Ad
Q2
.
0Ad
Q2 d
.
2 0A
QA
.
0d
Q
.
2 0Ad Chapter 26, section 5, Capacitors with Dielectrics Part 2 of 2
With the battery connected, ﬁll the gap by a
slab with the dielectric constant κ.
Compare the new plate charge Q with Q,
the plate charge in part 1. Choose one:
1. Q = κ Q
2. Q = (κ + 1) Q
3. Q = κ+1
Q
2 4. Q = (κ − 1) Q
5. Q =
6. Q =
7. Q =
8. Q =
9. Q =
10. Q = κ−1
Q
2
Q
κ
Q
κ+1
2Q
κ+1
Q
κ−1
2Q
κ−1 dielectric 2.6
constant
left 2 cm Qd
.
0A
Q
7. U =
.
0Ad
Q2 A
8. U =
.
0d 6. U = 80 dielectric
constant 6.7
right 0.75 mm
Calculate the capacitance C of the device.
Part 2 of 2
Vlef t
of electric potential
What is the ratio
Vright
across the dielectric in the lefthalf region to
that across the dielectric in the righthalf region?
Series Dielectric Energy
26:05, highSchool, multiple choice, > 1 min,
ﬁxed.
A capacitor is constructed from two metal
plates. The lefthand portion of a capacitor is
ﬁlled with air and righthand portion is ﬁlled
with a material of dielectric constant κ.
Given: The gap width of the lefthand
portion of the capacitor is the same as the
gap width of the righthand portion. Neglect
edge eﬀects. The size of the dielectric between
the plates is of equal size as the metal plates,
as shown in the ﬁgure below.
dielectric
constant κ Series Dielectric
26:05, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A capacitor is constructed from two square
metal plates. The gap between the plates
is ﬁlled with two dielectrics of equal size as
shown in the ﬁgure below. Neglect edge effects. E Ur
of energy stored in
U
right portion and the left portion.
Determine the ratio 1. Ur
1
=
U
κ Chapter 26, section 5, Capacitors with Dielectrics
2.
3.
4.
5.
6.
7.
8.
9.
10. Ur
U
Ur
U
Ur
U
Ur
U
Ur
U
Ur
U
Ur
U
Ur
U
Ur
U = 1
κ2 = κ2
=κ
= 1
κ+1 = 2κ
= 1
2κ = 2κ + 1
= 1
2κ + 1 =κ+1 81 Chapter 27, section 1, Electric Current
Car electrons
27:01, highSchool, numeric, > 1 min, normal. 82 tery can supply without being recharged is
given in terms of Amperehours. A typical
12V battery has a rating of 60 A · h . Suppose you forget to turn oﬀ the headlights in
your parked automobile.
If each of the two headlights draws 3 A , ﬁnd
out the time before your battery is “dead”. How long does it take electrons to get from
the car battery to the starting motor? Assume
the current is 115 A and the electrons travel
through copper wire with cross sectional area
31.2 mm2 and length 85.5 cm. The mass
density of copper is 8960 kg/m3 and the molar
mass is 63.5 g/mol. Holt SF 19A 01
27:01, highSchool, numeric, < 1 min, wordingvariable. Concept 23 E08
27:01, highSchool, multiple choice, < 1 min,
ﬁxed. If the current in a wire of a CD player is
5.00 mA, how long would it take for 2.00 C of
charge to pass a point in this wire? Does more current ﬂow out of a battery
than into it? Does more current ﬂow into a
light bulb than out of it? Holt SF 19A 02
27:01, highSchool, numeric, < 1 min, normal. 1. More for both
2. less; more
3. more; less
4. Less for both
5. The same for both
Conceptual 18 Q10
27:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A copper wire carries 1 amp of electric current.
What kind of charge does the electron ﬂow
create in the wire?
1. Positive
2. Negative
3. No charge.
Hewitt CP9 23 P04
27:01, highSchool, numeric, > 1 min, normal.
The total charge that an automobile bat In a particular television tube, a beam of
electrons has a current of 6 × 10−5 A .
The magnitude of the charge on an electron
is 1.602 × 10−19 C .
How long does it take for 3.75 × 1014 to
strike the screen?
Holt SF 19A 03
27:01, highSchool, numeric, < 1 min, wordingvariable.
If a metal wire carries a current of 80.0 mA,
how long does it take for 3.00×1020 electrons
to pass a given crosssectional area anywhere
along the wire? The magnitude of the charge
on an electron is 1.6 × 10−19 C.
Holt SF 19A 04
27:01, highSchool, numeric, < 1 min, wordingvariable.
The compressor on an air conditioner draws
40.0 A when it starts up.
If the startup time is 0.50 s, how much
charge passes a crosssectional area of the
circuit in this time?
Holt SF 19A 05
27:01, highSchool, numeric, > 1 min, wordingvariable. Chapter 27, section 1, Electric Current
Part 1 of 3
A total charge of 9.0 mC passes through
a crosssectional area of a nichrome wire in
3.5 s.
a) What is the current in the wire?
Part 2 of 3
b) How many electrons pass through the
crosssectional area in 10.0 s?
Part 3 of 3
c) If the number of charges that pass through
the crosssectional area during the given time
interval doubles, what is the resulting current?
Holt SF 19Rev 17
27:01, highSchool, numeric, < 1 min, wordingvariable.
How long does it take a total charge of 10.0
C to pass through a crosssectional area of a
copper wire that carries a current of 5.0 A?
Holt SF 19Rev 18
27:01, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A hair dryer draws a current of 9.1 A.
a) How long does it take for 1.9 × 103 C of
charge to pass through the hair dryer?
Part 2 of 2
b) How many electrons does this amount of
charge represent?
Holt SF 19Rev 19
27:01, highSchool, numeric, < 1 min, wordingvariable.
How long does it take for 5.0 C of charge to
pass through a crosssectional area of a copper
wire if I = 5.0 A?
Holt SF 19Rev 44
27:01, highSchool, numeric, < 1 min, wordingvariable. 83 Part 1 of 2
A net charge of 45 mC passes through the
crosssectional area of a wire in 15 s.
a) What is the current in the wire?
Part 2 of 2
b) How many electrons pass the crosssectional area in 1.0 min?
Holt SF 19Rev 46
27:01, highSchool, numeric, < 1 min, wordingvariable.
The current in a lightning bolt is 2.0 × 105
A.
How much charge passes through a crosssectional area of the lightning bolt in 0.50
s?
Holt SF 19Rev 54
27:01, highSchool, numeric, > 1 min, wordingvariable.
The mass of a gold atom is 3.27 × 10−25 kg.
If 1.25 kg of gold is deposited on the negative electrode of an electrolytic cell in a period
of 2.78 h, what is the current in the cell in this
period? Assume that each gold ion carries
one elementary unit of positive charge.
Holt SF 19Rev 58
27:01, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
The current in a conductor varies over time
as shown in the ﬁgure below. Chapter 27, section 1, Electric Current Current(A) 6 6
5
5
4 4
3
3
2 2
1
1
0 0
0 1 01 2 3 4 234
Time(s) 5 6 56 7 7 a) How much charge passes through a cross
section of the conductor in the time interval
t = 0 s to t = 5 s?
Part 2 of 2
b) What constant current would transport the
same total charge during the 5 s interval as
does the actual current? 84 Chapter 27, section 2, Current Density and Drift Speed
Hewitt CP9 23 03
27:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What is drift velocity?
1. the highest speed of an electron in a
metal
2. the lowest speed of an electron in a metal
3. the speed of an electric ﬁeld
4. the average speed of atoms in a liquid
5. the average speed of electrons in a conductor in an electric ﬁeld 85 Chapter 27, section 3, Resistance and Resistivity
Copper conductor
27:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following copper conductor
conditions has the least resistance?
1. thick, short, and cool
2. thick, short, and hot
3. thick, long, and cool
4. thick, long, and hot
5. thin, short, and cool
6. thin, short, and hot
7. thin, long, and cool
8. thin, long, and hot
Resistance and Resistivity JMS
27:03, highSchool, multiple choice, > 1 min,
ﬁxed.
A resistor is made from a hollow cylinder
of length l, inner radius a, and outer radius b.
The region a < r < b is ﬁlled with material of
resistivity ρ. Current runs along the axis of
the cylinder.
The resistance R of this component is
ρ
π b2
ρ
2. R =
π a2
π b2 ρ
3. R = 1. R = 4. R =
5. R =
6. R = π b2 − a 2 ρ
ρ
− a2 ) π (b 2 ρ b2
π a4 ρa
π b2
ρ a2
8. R =
π b4
2ρ
9. R =
π b2
2πρ
10. R = 2
(b − a 2 )
7. R = 86 Chapter 27, section 4, Ohm’s Law
Hewitt CP9 23 01
27:04, highSchool, multiple choice, < 1 min,
ﬁxed.
How will a current change if the voltage in
a circuit is held constant while the resistance
doubles?
1. The current will remain the same.
2. The current will double.
3. The current will triple.
4. The current will drop to half of its original
value. 87 device in a 120 V circuit has a current rating
of 20 A.
What is the resistance of the device?
Hewitt CP9 23 09
27:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
What is the eﬀect on the current in a wire
if both the voltage across it and its resistance
are doubled?
1. The current is doubled.
2. The current is 4 times bigger.
3. The current does not change. 5. It’s impossible to predict.
4. The current is halved.
Hewitt CP9 23 02
27:04, highSchool, multiple choice, < 1 min,
ﬁxed.
How will a current change if the resistance
of a circuit remains constant while the voltage
across the circuit decreases to half its original
value?
1. The current will remain the same. 5. The current is reduced to a quarter of its
original value.
6. It cannot be determined.
Part 2 of 2
What is the eﬀect on the current in a wire if
both the voltage across it and its resistance
are halved? 2. The current will double. 1. The current is doubled. 3. The current will triple. 2. The current is 4 times bigger. 4. The current will drop to half of its original
value. 3. The current does not change.
4. The current is halved. 5. It’s impossible to predict.
Hewitt CP9 23 02a
27:04, highSchool, numeric, < 1 min, normal. 5. The current is reduced to a quarter of its
original value.
6. It cannot be determined. Rearrange the equation
Voltage
Current =
Resistance
to express resistance in terms of current and
voltage. Then solve the following: A certain Hewitt CP9 23 10
27:04, highSchool, multiple choice, < 1 min,
normal.
How does the current in a light bulb con Chapter 27, section 4, Ohm’s Law
nected to a 220 V source compare to the current when this light bulb is connected to a
110 V source? 88 What is the current in this device?
Holt SF 19B 03
27:04, highSchool, numeric, > 1 min, normal. 1. The 220 V current is larger.
2. The 110 V current is larger.
3. The currents are equal.
4. It cannot be determined.
Hewitt CP9 23 P02
27:04, highSchool, numeric, < 1 min, ﬁxed.
A certain device in a 120 V circuit has a
current rating of 20 A .
Find the resistance of the device.
Hewitt CP9 23 R11
27:04, highSchool, multiple choice, < 1 min,
ﬁxed.
How will the current change if the voltage in
a circuit is held constant while the resistance
halves?
1. The current remains unchanged.
2. The current halves.
3. The current doubles.
4. The current quadruples.
5. It’s impossible to predict.
Holt SF 19B 01
27:04, highSchool, numeric, < 1 min, normal.
A 1.5 V battery is connected to a small light
bulb with a resistance of 3.5 Ω.
What is the current in the bulb?
Holt SF 19B 02
27:04, highSchool, numeric, < 1 min, normal.
A stereo with a resistance of 65 Ω is connected across a potential diﬀerence of 120 V. Part 1 of 2
A hot plate connected across a potential
diﬀerence of 120 V has a resistance of 48 Ω.
a) What is the current in the hot plate?
Part 2 of 2
A microwave oven connected across a potential diﬀerence of 120 V has a resistance of
20 Ω.
b) What is the current in the microwave
oven?
Holt SF 19B 04
27:04, highSchool, numeric, < 1 min, normal.
The current in a microwave oven is 6.25 A.
If the resistance of the oven’s circuitry is
17.6 Ω, what is the potential diﬀerence across
the oven?
Holt SF 19B 05
27:04, highSchool, numeric, < 1 min, normal.
A typical color television draws 2.5 A of
current when connected across a potential difference of 115 V.
What is the eﬀective resistance of the television set?
Holt SF 19B 06
27:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The current in a certain resistor is 0.50 A
when it is connected to a potential diﬀerence
of 110 V.
a) What is the current in this same resistor
if the operating potential diﬀerence is 90.0 V?
Part 2 of 2
b) What is the current in the resistor when
the operating potential diﬀerence if 130 V? Chapter 27, section 4, Ohm’s Law 89 Holt SF 19Rev 28
27:04, highSchool, numeric, < 1 min, wordingvariable. Part 3 of 3
A 20 Ω resistor is connected to a 9 V battery
in the circuit below. A nichrome wire with a resistance of 15 Ω
is connected across the terminals of a 3.0 V
ﬂashlight battery.
How much current is in the wire? 20 Ω Holt SF 19Rev 29
27:04, highSchool, numeric, < 1 min, normal.
How much current is drawn by a television
with a resistance of 35 Ω that is connected
across a potential diﬀerence of 120 V? 9V S
I c) When the switch is closed, calculate the
current I . Holt SF 19Rev 30
27:04, highSchool, numeric, > 1 min, normal. Holt SF 19Rev 45
27:04, highSchool, numeric, < 1 min, wordingvariable. Part 1 of 3
A 5 Ω resistor is connected to a 9 V battery
in the circuit below. A potential diﬀerence of 12 V produces a
current of 0.40 A in a piece of copper wire.
What is the resistance of the wire? 5Ω Holt SF 19Rev 59
27:04, highSchool, numeric, < 1 min, wordingvariable.
9V S
I a) When the switch is closed, calculate the
current I .
Part 2 of 3
A 2 Ω resistor is connected to a 9 V battery
in the circuit below.
2Ω
9V S
I b) When the switch is closed, calculate the
current I . Birds resting on highvoltage power lines
are a common sight. A certain copper power
line carries a current of 50.0 A, and its resistance per unit length is 1.12 × 10−5 Ω/m.
If a bird is standing on this line with its feet
4.0 cm apart, what is the potential diﬀerence
across the bird’s feet? Chapter 27, section 5, Microscopic View of Ohm’s Law
Concept 23 E17
27:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Why are thick wires rather than thin wires
usually used to carry large current? 90 How do the length, diameter and temperature of a copper wire aﬀect its resistance?
1. A longer wire will have more resistance,
a larger diameter wire will have less resistance, and higher temperatures mean higher
resistance. 1. Thick wires have less resistance.
2. Thick wires have a larger heat capacity.
3. Thick wires are diﬃcult to break.
4. Thick wires are easier to make.
Concept 23 E19
27:05, highSchool, numeric, < 1 min, normal.
Part 1 of 2
A 1mile long copper wire has a resistance
of 10 Ω.
What will be its new resistance when it is
shortened by cutting it in half?
Part 2 of 2
What will be its new resistance when it is
shortened a second time by doubling it over
and using it as “one” wire?
Conceptual 18 Q09
27:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider the thickness of a wire.
What is true?
1. A thicker wire has less resistance than
thinner wire.
2. A thicker wire has more resistance than
thinner wire.
3. Both wires have the same resistance since
they are made of the same material. 1. A longer wire will have less resistance,
a larger diameter wire will have more resistance, and higher temperatures mean less resistance.
2. A longer wire will have more resistance,
a larger diameter wire will have less resistance, and higher temperatures mean less resistance.
3. A longer wire will have more resistance,
a larger diameter wire will have more resistance, and higher temperatures mean higher
resistance.
4. A longer wire will have less resistance,
a larger diameter wire will have more resistance, and higher temperatures mean higher
resistance.
Conceptual 18 Q17
27:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Even though copper conducts electricity
very well, it does have some resistance.
How would the resistance of a 1meterlong
thick copper wire compare to the resistance of
a 1meterlong thin copper wire?
1. 1meterlong thick copper wire will have
higher resistance.
2. 1meterlong thin copper wire will have
higher resistance.
3. The will have the same resistance. Conceptual 18 Q11
27:05, highSchool, multiple choice, < 1 min,
ﬁxed. Conceptual 18 Q19
27:05, highSchool, multiple choice, < 1 min, Chapter 27, section 5, Microscopic View of Ohm’s Law
ﬁxed.
Which of the following is correct?
1. 50watt lightbulb has more resistance.
2. 100watt lightbulb has more resistance.
Figuring Physics 17
27:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Roll a piece of modeling clay into a cylinder
and use an ohmmeter to measure its resistance. R ? ¡ Now roll it out until it is twice as long, and
measure the resistance again. Compared with
the initial resistance, the new resistance is
1. unchanged.
2. twice as much.
3. four times as much.
4. eight times as much.
5. actually less.
Hewitt CP9 23 08
27:05, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A 1 mile long copper wire that has a resistance of 10 ohm is cut in half.
What is the resistance of one of the halves?
Part 2 of 2
What will be the new resistance if the two
halves are doubled over and used as one wire? 91 Chapter 27, section 6, Resistance and Temperature 92 age and current.
Concept 23 E12
27:06, highSchool, multiple choice, < 1 min,
ﬁxed.
An electron moving in a wire collides again
and again with atoms and travels an average
distance between collisions that is called the
mean free path.
For a given conductor, what can you do to
lengthen the mean free path?
1. Cool the conductor
2. Heat the conductor
3. Apply a large voltage across the conductor 3. The resistance remains constant with
both voltage and current.
4. Cannot be determined from the information.
Part 2 of 2
From your personal experience, can you predict whether the temperature of the ﬁlament
of the lightbulb increases or decreases with
the voltage?
1. The higher the temperature the higher
the resistance
2. The lower the temperature the higher the
resistance 4. Place the conductor in a vacuum
3. Voltage has no eﬀect on resistance.
Conceptual 18 07
27:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Giselle and Anna decided to impress their
physical science professor with a simple experiment investigating the resistance of a 100
W lighbulb. They used a VARIAC (which
provides a variable voltage to a circuit) in a
series circuit with one 100W lightbulb. They
measured the current and voltage, which are
listed in the following table.
Voltage (Volts)
Currents (amps)
120
0.81
100
0.72
80
0.62
60
0.51
40
0.40
20
0.23
Does the resistance of the lighbulb increase
or decrease for each voltage and current setting?
1. The resistance increases with both voltage
and current.
2. The resistance decreases with both volt Hewitt CP9 15 E39
27:06, highSchool, multiple choice, < 1 min,
ﬁxed.
One of the reasons the ﬁrst light bulbs were
expensive was that the electrical lead wires
were made of platinum.
What is wrong?
1. The metal leads and the glass have the
same coeﬃcient of expansion.
2. Platinum expands at about the same rate
as glass when heated.
3. The metal leads and the glass have the
same coeﬃcient of resistance.
4. If the metal leads expand more than glass,
the glass may crack.
5. If the metal expands less than glass upon
being heated, air will leak in through the
resulting gaps. Chapter 27, section 7, Semiconductors
Conceptual 24 Q11
27:07, highSchool, multiple choice, < 1 min,
wordingvariable.
If the temperature of a semiconductor is
decreased what happens to its electrical resistance.
1. increases
2. decreases
3. No change
Hewitt CP9 12 E01
27:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Silicon is the main ingredient of both glass
and semiconductor materials.
Why are the physical properties of glass
diﬀerent from those of semiconductors?
1. The silicon in glass does not have electrons, while the silicon in semiconductors
does.
2. The silicon atoms in semiconductors form
a crystal; in glass they are bonded with oxygen atoms to form the amorphous silicon dioxide.
3. The silicon atoms in semiconductors are
bonded with oxygen atoms to form a crystal;
in semiconductors the silicon is pure and thus
forms the amorphous structure.
4. Silicon has no eﬀect on the properties of
glass and semiconductors. 93 Chapter 27, section 8, Superconductors
Conceptual 24 Q12
27:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Based on Ohm’s law, how much current
would you expect to run through a superconductor if the voltage across it were 100 volts?
1. inﬁnite current
2. high current; superconductor breaks
down.
3. no current
4. 100 A current 94 Chapter 27, section 9, Electrical Energy and Power
Change potential
27:09, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
A potential diﬀerence V is applied to a wire
of crosssection area of 1 unit, length 1 unit,
and conductivity σ . You want to change the
applied potential diﬀerence and draw out the
wire so the power dissipated is increased by a
factor of 30 and the current is increased by a
factor of 4 .
What should be the new values of the
length? 95 Conceptual 18 Q21
27:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Two lightbulbs are wired in series and connected to a 12volt battery.
What happens to the current through the
battery if a third bulb is wired in parallel with
the other two bulbs? To the power?
1. Both increase.
2. Both decrease.
3. Decreases; increases Part 2 of 2
b) What is the new cross sectional area?
Conceptual 18 05
27:09, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A typical 1.5 V alkaline D battery is rated
at 3.5 amphours.
What is the power that can be expended by
the battery? 4. Increases; decreases
Hewitt CP9 23 11
27:09, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
What unit is equivalent to “Joule per
Coulomb?”
1. volt Part 2 of 2
What is the total energy stored by this battery? 2. Ampere
3. Coulomb Conceptual 18 Q20
27:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Two lightbulbs are wired in series and connected to a 12volt battery.
What happens to the current through the
battery if a third bulb is added in series? To
the power?
1. Both decrease. 4. kilogram
5. Ohm
6. Joule
7. Watt
Part 2 of 3
What unit is equivalent to “Coulomb per second?” 2. Both increase.
1. volt
3. Increases; decreases 2. Ampere 4. Decreases; increases
3. Coulomb Chapter 27, section 9, Electrical Energy and Power
4. kilogram
5. Ohm
6. Joule 96 It is estimated that in the United States
(population 250 million) there is one electric
clock per person, with each clock using energy
at a rate of 2.5 W.
Using this estimate, how much energy is
consumed by all of the electric clocks in the
United States in a year? 7. Watt
Part 3 of 3
What unit is equivalent to “Watt · second ?”
1. volt
2. Ampere Holt SF 19Rev 50
27:09, highSchool, numeric, < 1 min, wordingvariable.
An Xray tube used for cancer therapy operates at 4.0 MV with a beam current of 25
mA striking a metal target.
Calculate the power of this beam. 3. Coulomb
4. kilogram Holt SF 19Rev 57
27:09, highSchool, numeric, < 1 min, wordingvariable. 5. Ohm
6. Joule
7. Watt
Hewitt CP9 23 P03
27:09, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
Using Power = current×voltage, ﬁnd the
current drawn by a 1200 W hair dryer connected to 120 V .
Part 2 of 2
Find the resistance of the hairdryer.
Holt SF 19C 03
27:09, highSchool, numeric, < 1 min, wordingvariable.
A calculator is rated at 0.10 W when connected to 1.50 V battery.
What is the resistance of this device?
Holt SF 19Rev 38
27:09, highSchool, numeric, < 1 min, wordingvariable. The headlights on a car are rated at 80.0
W.
If they are connected to a fully charged 90.0
A·h, 12.0 V battery, how long does it take the
battery to completely discharge?
Holt SF 19Rev 60
27:09, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
An electric car is designed to run on a bank
of batteries with a total potential diﬀerence of
12 V and a total energy storage of 2.0×107 J.
a) If the electric motor draws 8.0 kW, what
is the current delivered to the motor?
Part 2 of 2
b) If the electric motor draws 8.0 kW as the
car moves at a steady speed of 20.0 m/s, how
far will the car travel before it is “out of
juice”?
Lightbulb 75 watts
27:09, highSchool, multiple choice, < 1 min,
ﬁxed.
You buy a 75 watt light bulb. Chapter 27, section 9, Electrical Energy and Power
The label means that
1. no matter how you use the bulb, the
power will be 75 watts.
2. the bulb was ﬁlled with 75 W at the
factory.
3. the actual power dissipated will be much
higher than 75 W since most of the power
appears as heat.
4. the bulb is expected to burn out after you
use up its 75 watts.
5. the power will be 75 watts if standard
household voltage is applied to it. 97 Chapter 27, section 10, Power in Household Circuits
Christmas Lights 03
27:10, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A string of 18 identical Christmas tree
lights are connected in series to a 120 V
source. The string dissipates 64 W.
What is the equivalent resistance of the
light string?
Part 2 of 2
What is the resistance of a single light?
Conceptual 18 08
27:10, highSchool, multiple choice, < 1 min,
wordingvariable.
Most household circuits have fuses or circuit breakers that open a switch when the
current in the circuit exceeds 15 A.
What will happen when you plug in an air
conditioner (1 kilowatt), a TV (250 watts),
and four 100 watt lightbulbs?
1. The circuit breaker would not open
2. The circuit breaker would open
3. Cannot be determined from the information.
Conceptual 18 10
27:10, highSchool, numeric, > 1 min, normal.
An energyeﬃcient air conditioner draws
7 A in a standard 120volt circuit. It costs
$40 more than a standard air conditioner that
draws 12 A.
If electricity costs 8 cents per kilowatthour,
how long would you have to run the eﬃcient
air conditioner to recoup the diﬀerence in
price?
Filament
27:10, highSchool, multiple choice, < 1 min,
normal.
A 1000 W bulb and a 500 W bulb are both 98 designed to operate at standard household
voltage of 120 V.
Determine which bulb has the lower ﬁlament resistance and then calculate the value
of its resistance.
Hewitt CP9 23 01a
27:10, highSchool, numeric, < 1 min, normal.
Find the current through a 60 W bulb connected to a 120 V circuit.
Hewitt CP9 23 P01
27:10, highSchool, multiple choice, < 1 min,
ﬁxed.
The voltage marked on a light bulb is usually either 110 or 120 V .
The power of a light bulb is 60 W . It
is connected to a power supply with voltage
120 V .
Find the current ﬂowing through the light
bulb.
Hewitt CP9 23 P05
27:10, highSchool, numeric, > 1 min, ﬁxed.
How much does it cost to operate a 100 W
lamp continuously for one week if the power
utility rate is 0.15 dollars/kWh?
Hewitt CP9 23 P06
27:10, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
An electric iron connected to a 110 V source
draws 9 A of current.
Find the heat the iron generates in a
minute.
Part 2 of 2
Find the charge ﬂowing through the iron in
one minute.
Hewitt CP9 23 P07
27:10, highSchool, numeric, > 1 min, ﬁxed.
A certain light bulb with a resistance of
95 Ω (when the bulb is on) is labeled 150 W. Chapter 27, section 10, Power in Household Circuits 99 What voltage was this light bulb designed
to use? when connected to 120 V.
What is the resistance of this device? Hewitt CP9 23 R27
27:10, highSchool, multiple choice, < 1 min,
ﬁxed. Holt SF 19C 04
27:10, highSchool, numeric, < 1 min, wordingvariable. When you pay your household electric bill
at the end of the month, which of the following
are you paying for? Part 1 of 2
An electric heater is operated by applying a potential diﬀerence of 50.0 V across a
nichrome wire of total resistance 8.00 Ω.
a) Find the current in the wire. 1. voltage
2. current Part 2 of 2
b) Find the power rating of the heater. 3. power
4. energy
Hewitt CP9 25 P05
27:10, highSchool, numeric, > 1 min, normal.
Part 1 of 3
100 kW of power is delivered to the other
side of a city by a pair of power lines with the
voltage diﬀerence of 12000 V.
a) How much current ﬂows in the lines?
Part 2 of 3
b) Each of the two lines has a resistance of
10 Ω.
What is the voltage change along each line?
Part 3 of 3
c) How much power is wasted as heat in both
lines together?
Holt SF 19C 01
27:10, highSchool, numeric, < 1 min, normal.
A 1050 W electric toaster operates on a
household circuit of 120 V.
What is the resistance of the wire that
makes up the heating element of the toaster?
Holt SF 19C 02
27:10, highSchool, numeric, < 1 min, normal.
A small electronic device is rated at 0.25 W Holt SF 19D 01
27:10, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Assume electrical energy costs $0.080 per
kW·h, and that appliances have a potential
diﬀerence across them of 115 V.
a) Calculate the cost of running a 75.0 W
stereo for 24 h.
Part 2 of 3
b) Calculate the cost of running an electric
oven that draws 20.0 A of current for 24 h.
Part 3 of 3
c) Calculate the cost of running a television
with a resistance of 60.0 Ω for 24 h.
Holt SF 19D 02
27:10, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Several appliances are supplied with a potential diﬀerence of 115 V and are operated
continuously for a 24 h period.
a) How much energy is used if the appliance
is a 75.0 W stereo?
Part 2 of 3
b) How much of energy is used if the appli Chapter 27, section 10, Power in Household Circuits
ance is an electric oven that draws 20.0 A of
current?
Part 3 of 3
c) How much energy is used if the appliance
is a television with a resistance of 60.0 Ω.
Holt SF 19Rev 34
27:10, highSchool, numeric, < 1 min, wordingvariable.
How much energy is dissipated by 50.0 W
light bulb in 1.00 s? 100 Holt SF 19Rev 48
27:10, highSchool, numeric, < 1 min, wordingvariable.
How much power is needed to operate a
radio that draws 7.0 A of current when a
potential diﬀerence of 115 V is applied across
it?
Holt SF 19Rev 49
27:10, highSchool, numeric, < 1 min, normal. Holt SF 19Rev 40
27:10, highSchool, numeric, < 1 min, normal. A color television has a power rating of
325 W.
How much current does this set draw from
a potential diﬀerence of 120 V? A computer is connected across a 110 V
power supply. The computer dissipates 130 W
of power in the form of electromagnetic radiation and heat.
Calculate the resistance of the computer. Holt SF 19Rev 51
27:10, highSchool, numeric, > 1 min, wordingvariable. Holt SF 19Rev 41
27:10, highSchool, numeric, < 1 min, normal. Part 1 of 3
A steam iron draws 6.0 A when connected
to a potential diﬀerence of 120 V.
a) What is the power rating of this iron? Part 1 of 2
The operating potential diﬀerence of a light
bulb is 120 V. The power rating of the bulb
is 75 W.
a) Find the current in the bulb.
Part 2 of 2
b) Find the bulb’s resistance.
Holt SF 19Rev 42
27:10, highSchool, numeric, < 1 min, wordingvariable.
How much would it cost to watch a football game for 3.0 h on a 325 W television if
electrical energy costs $0.08 /kW · h?
Holt SF 19Rev 43
27:10, highSchool, numeric, < 1 min, normal.
Calculate the cost of operating a 75 W light
bulb continuously for a 30day month when
electrical energy costs $0.15 /kW · h. Part 2 of 3
b) How much energy is produced in 20.0 min?
Part 3 of 3
c) How much does it cost to run the iron for
20.0 min at $0.010/kW·h?
Holt SF 19Rev 52
27:10, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
An 11.0 W energyeﬃcient ﬂuorescent lamp
is designed to produce the same illumination
as a conventional 40.0 W lamp.
a) How much energy does this lamp save
during 100.0 h of use?
Part 2 of 2
b) If electrical energy costs $0.080/kW·h, how
much money is saved in 100.0 h? Chapter 27, section 10, Power in Household Circuits
Holt SF 19Rev 53
27:10, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
Use the electric bill shown in the ﬁgure.
In 33 days you used
Read Date
01/21/00
12/19/99
Diﬀerence 471 kWh
Meter # 0079051
60591
60120
471 Rate Calculation:
Residential Service Rate, Multifuel
Customer Charge:
Energy: 471 kWh at $.03550/kWh
Fuel:
471 kWh at $.01467/kWh
Subtotal Electric Charges
Sales Tax
Total Cost for Electric Service
For this 33 days period, your
average daily cost for Electric
service was $0.91 $6.00
16.72
6.91
$29.63
0.30
$29.93 a) How much energy was consumed in this
billing cycle?
Part 2 of 4
b) What is the average energy consumed per
day in kilowatthours?
Part 3 of 4
c) What is the average energy consumed per
day in Joules?
Part 4 of 4
d) If the cost of energy were increased to
$0.15 /kWh, how much more would energy
cost in this billing cycle? (Assume that the
price of fuel remains constant.)
Holt SF 19Rev 55 56
27:10, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
The power supplied to a typical blackandwhite television is 90.0 W when the set is con 101 nected across a potential diﬀerence of 120 V.
a) How much electrical energy does this set
consume in 1.0 h?
Part 2 of 2
A color television set draws about 2.5 A of
current when connected to a potential diﬀerence of 120 V.
b) How much time is required for it to
consume the same energy that the blackandwhite model consumes in 1.0 h?
Lightbulb100W
27:10, highSchool, numeric, > 1 min, normal.
Part 1 of 3
A 100 W light bulb is plugged into a standard 120 V outlet.
a) How much does it cost per month (31
days) to leave the light turned on? Assume
electric energy cost of 6 cents/kW · h.
Part 2 of 3
b) What is the resistance of the bulb?
Part 3 of 3
c) What is the current in the bulb? Chapter 28, section 3, Resistance: Series Circuits 102 Concept 23 E44
28:03, highSchool, multiple choice, < 1 min,
wordingvariable.
When a pair of identical resistors are connected in series, the
A) current
B) power
C) voltage
will be the same for each resistor. A B
1. Bulb A would again be brighter.
2. Bulb B would be brighter. 1. All of these 3. Either of the above would occur. 2. None of these Hewitt CP9 23 04
28:03, highSchool, multiple choice, < 1 min,
normal. 3. A only
4. B only Part 1 of 2
In a circuit of two lamps in series, if the
current through one lamp is 1 A, what is the
current through the other lamp? 5. C only
6. A and B only
7. A and C only
8. B and C only
Figuring Physics 21
28:03, highSchool, multiple choice, < 1 min,
ﬁxed.
When the series circuit shown below E E B Part 2 of 2
If 6 V is applied to the above circuit and the
voltage across the ﬁrst lamp is 2 V, what is
the voltage across the second lamp?
Hewitt CP9 23 05
28:03, highSchool, multiple choice, < 1 min,
normal.
If 6 V are impressed across a circuit of two
lamps in series and the voltage across the ﬁrst
lamp is 2 V, what is the voltage across the
second lamp? Note: The lamps are not the
same.
1. 4 V A
is connected, Bulb A is brighter than Bulb B.
If the positions of the bulbs were reversed, 2. 3 V
3. 12 V
4. 10 V
5. 9 V Chapter 28, section 3, Resistance: Series Circuits
6. 5 V
Holt SF 20A 01
28:03, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A 12.0 V storage battery is connected to
three resistors, 6.75 Ω, 15.3 Ω, and 21.6 Ω,
respectively. The resistors are joined in series.
Calculate the equivalent resistance.
Part 2 of 2
What is the current in the circuit?
Holt SF 20A 02
28:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A 4.0 Ω, an 8.0 Ω and a 12.0 Ω resistor are
connected in series with a 24.0 V battery.
Calculate the equivalent resistance.
Part 2 of 3
What is the current in the circuit? 103 Part 3 of 4
Find the potential diﬀerence across the 5.0 Ω
resistor.
Part 4 of 4
Find the potential diﬀerence across the 7.0 Ω
resistor.
Holt SF 20A 04
28:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A series combination of two resistors, 7.25
Ω, and 4.03 Ω, is connected to a 9.00 V battery.
Calculate the equivalent resistance of the
circuit.
Part 2 of 4
Calculate the current in the circuit.
Part 3 of 4
What is the potential diﬀerence across the
7.25 Ω resistor? Part 3 of 3
What is the current in each resistor? Part 4 of 4
What is the potential diﬀerence across the
4.03 Ω resistor? Holt SF 20A 03
28:03, highSchool, numeric, < 1 min, wordingvariable. Holt SF 20A 05
28:03, highSchool, numeric, < 1 min, wordingvariable. Part 1 of 4
Consider the circuit in the ﬁgure.
2Ω
4Ω
5Ω
7Ω 0.50 A E S Find the potential diﬀerence across the 2.0
Ω resistor.
Part 2 of 4
Find the potential diﬀerence across the 4.0 Ω
resistor. A 7.0 Ω resistor is connected in series with
another resistor and a 4.5 V battery. The
current in the circuit is 0.60 A.
Calculate the value of the unknown resistance.
Holt SF 20A 06
28:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Several light bulbs are connected in series
across a 115 V source of emf.
What is the equivalent resistance if the cur Chapter 28, section 3, Resistance: Series Circuits 104 rent in the circuit is 1.70 A? variable. Part 2 of 2
If each light bulb has a resistance of 1.50 Ω,
how many light bulbs are in the circuit? Part 1 of 3
18.0 Ω, 9.00 Ω, and 6.00 Ω resistors are
connected in series with an emf source. The
current in the 9.00 Ω resistor is measured to
be 4.00 A.
a) Calculate the equivalent resistance of the
three resistors in the circuit. Holt SF 20Rev 16
28:03, highSchool, numeric, < 1 min, wordingvariable.
A length of wire is cut into ﬁve equal pieces.
If each piece has a resistance of 0.15 Ω,
what was the resistance of the original length
of wire?
Holt SF 20Rev 27
28:03, highSchool, numeric, < 1 min, wordingvariable. Part 2 of 3
b) Find the potential diﬀerence across the emf
source
Part 3 of 3
c) Find the current in the other resistors.
Holt SF 20Rev 37
28:03, highSchool, numeric, > 1 min, wordingvariable. An 8.0 Ω resistor and a 6.0 Ω resistor are
connected in series with a battery. The potential diﬀerence across the 6.0 Ω resistor is
measured as 12 V.
Find the potential diﬀerence across the battery. Part 1 of 3
An 18 Ω resistor and a 6 Ω resistor are
connected in series to an 18 V battery.
Find the current in each resistor. Holt SF 20Rev 29
28:03, highSchool, numeric, < 1 min, wordingvariable. Part 2 of 3
Find the potential diﬀerence across the ﬁrst
resistor. A 9.0 Ω resistor and a 6.0 Ω resistor are connected in series to a battery, and the current
through the 9.0 Ω resistor is 0.25 A.
Find the potential diﬀerence across the battery. Part 3 of 3
Find the potential diﬀerence across the second
resistor. Holt SF 20Rev 30
28:03, highSchool, numeric, < 1 min, wordingvariable.
A 9.0 Ω resistor and a 6.0 Ω resistor are
connected in series with an emf source. The
potential diﬀerence across the 6.0 Ω resistor
is measured with a voltmeter to be 12 V.
Find the potential diﬀerence across the emf
source.
Holt SF 20Rev 31
28:03, highSchool, numeric, > 1 min, wording Holt SF 20Rev 44
28:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Two resistors A and B are connected in
series to a 6 V battery. A voltmeter connected across resistor A measures a potential
diﬀerence of 4 V. When the two resistors are
connected in parallel across the 6 V battery,
the current in B is found to be 2 A.
Find the resistance of B.
Part 2 of 2
Find the resistance of A. Chapter 28, section 3, Resistance: Series Circuits
Short a Light Bulb 01
28:03, highSchool, multiple choice, > 1 min,
ﬁxed.
Two identical light bulbs A and B are connected in series to a constant voltage source.
Suppose a wire is connected across bulb B as
shown. A E B After the wire is connected across B ,
1. bulb A will go out and bulb B will go
out.
2. bulb A will go out and bulb B will burn
half as brightly as before.
3. bulb A will go out and bulb B will burn
as brightly as before.
4. bulb A will burn twice as brightly as
before and bulb B will go out.
5. bulb A will burn twice as brightly as
before and bulb B will burn half as brightly
as before.
6. bulb A will burn twice as brightly as
before and bulb B will burn as brightly as
before.
7. bulb A will burn as brightly as before and
bulb B will go out.
8. bulb A will burn as brightly as before and
bulb B will burn half as brightly as before.
9. bulb A will burn as brightly as before and
bulb B will burn as brightly as before.
10. bulb A will burn four times as brightly as
before and bulb B will go out. 105 Chapter 28, section 4, Resistance: Series/Parallel Combinations
Four Resistors JMS
28:04, highSchool, multiple choice, > 1 min,
normal.
Four resistors are connected as shown in
the ﬁgure.
c
50
Ω
Ω
10
b 30 Ω a 90 V 0Ω Part 2 of 4
Calculate the current in the 4.0 Ω resistor
(second from the top).
Part 3 of 4
Calculate the current in the 5.0 Ω resistor
(third from the top).
Part 4 of 4
Calculate the current in the 7.0 Ω resistor
(fourth from the top). 7 S1 d Find the resistance between points a and
b.
Hewitt CP9 23 06
28:04, highSchool, numeric, < 1 min, normal.
In a circuit of two lamps in parallel there is
6 V across one lamp.
What is the voltage across the other
lamp?
Holt SF 20B 01
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A 9.0 V battery is connected to four resistors, as in the ﬁgure.
2Ω Holt SF 20B 02
28:04, highSchool, numeric, > 1 min, wordingvariable.
A length of wire is cut into ﬁve equal pieces.
The ﬁve pieces are then connected in parallel,
with the resulting resistance being 24.0 Ω.
What was the resistance of the original
length of wire before it was cut up?
Holt SF 20B 03
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A 4.0 Ω resistor, an 8.0 Ω resistor, and a
12.0 Ω resistor are connected in parallel across
a 24.0 V battery.
What is the equivalent resistance of the
circuit?
Part 2 of 4
What is the current in the 4.0 Ω resistor?
Part 3 of 4
What is the current in the 8.0 Ω resistor? 4Ω
5Ω
7Ω I 106 9. 0 V S Calculate the current in the top 2.0 Ω resistor. Part 4 of 4
What is the current in the 12.0 Ω resistor?
Holt SF 20B 04
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An 18.0 Ω, 9.00 Ω, and 6.00 Ω resistor are Chapter 28, section 4, Resistance: Series/Parallel Combinations
connected in parallel to an emf source. A
current of 4.00 A is in the 9.00 Ω resistor.
Calculate the equivalent resistance of the
circuit. 107 A 4 Ω resistor, an 8 Ω resistor, and a 12 Ω
resistor are connected in parallel across a 24 V
battery.
a) Determine the equivalent resistance for
the circuit. Part 2 of 4
What is the potential diﬀerence across the
source? Part 2 of 2
b) Determine the current in the circuit. Part 3 of 4
Calculate the current in the 18.0 Ω resistor. Holt SF 20Rev 23
28:04, highSchool, numeric, < 1 min, normal.
18 Ω Part 4 of 4
Calculate the current in the 6.00 Ω resistor. 9Ω
Holt SF 20C 01
28:04, highSchool, numeric, > 1 min, normal.
Consider the circuit shown in the ﬁgure.
40 Ω
25 Ω
3Ω
I 40 V 12 Ω 6Ω I 30 V S Find the equivalent resistance of the circuit
shown in the ﬁgure.
Holt SF 20Rev 24
28:04, highSchool, numeric, < 1 min, normal. Find its equivalent resistance.
Holt SF 20C 02
28:04, highSchool, numeric, > 1 min, normal. Find the equivalent resistance of the circuit
shown in the ﬁgure.
7Ω
7Ω Consider the circuit shown in the ﬁgure.
25 Ω
40 Ω 7Ω
7Ω 12 V 1.5 Ω 3Ω
15 Ω
25 V
18 Ω
Find its equivalent resistance.
Holt SF 20Rev 18
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2 Holt SF 20Rev 28
28:04, highSchool, numeric, < 1 min, wordingvariable.
A 9.0 Ω resistor and a 6.00 Ω resistor are
connected in parallel to a battery, and the
current in the 9.0 Ω resistor is found to be
0.250 A.
Find the potential diﬀerence across the battery. Chapter 28, section 4, Resistance: Series/Parallel Combinations 108 in the ﬁgure?
Holt SF 20Rev 33
28:04, highSchool, numeric, > 1 min, wordingvariable. 6.0 Ω The equivalent resistance of the circuit in
the ﬁgure is Req = 66.0 Ω .
17 Ω
89 Ω 6.0 Ω 89 Ω
R 17 Ω
E S 6.0 Ω Part 4 of 5
What is the equivalent resistance of the circuit
in the ﬁgure?
6. 0 Ω
6.0 Ω
6.0 Ω Find the value of R.
Holt SF 20Rev 34
28:04, highSchool, numeric, < 1 min, wordingvariable. Part 5 of 5
What is the equivalent resistance?
6.0 Ω
6. 0 Ω
6.0 Ω Two identical parallelwired strings of 25
bulbs are connected to each other in series.
If the equivalent resistance of the combination is 150.0 Ω when it is connected across
a potential diﬀerence of 120.0 V, what is the
resistance of each individual bulb? Holt SF 20Rev 39
28:04, highSchool, numeric, < 1 min, wordingvariable. Holt SF 20Rev 35
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 5
In the following circuit diagrams, each individual resistance is 6.0 Ω.
What is the equivalent resistance of the
circuit in the ﬁgure?
6. 0 Ω
6. 0 Ω
Part 2 of 5
What is the equivalent resistance of the circuit
in the ﬁgure?
6. 0 Ω
6. 0 Ω
Part 3 of 5
What is the equivalent resistance of the circuit A resistor with an unknown resistance is
connected in parallel to a 12 Ω resistor. When
both resistors are connected in parallel to an
emf source of 12 V, the current across the unknown resistor is measured with an ammeter
to be 3 A.
What is the resistance of the unknown resistor?
Holt SF 20Rev 40
28:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Two resistors 18.0 Ω and 6.0 Ω are connected in parallel across an 18.0 V battery.
a) Find the potential diﬀerence across each
resistor.
Part 2 of 3
b) Find the current in the ﬁrst resistor. Chapter 28, section 4, Resistance: Series/Parallel Combinations
Part 3 of 3
c) Find the current in the circuit.
Holt SF 20Rev 41
28:04, highSchool, numeric, > 1 min, normal.
In the circuit shown below, the current i in
the resistor R doubles its original value when
the switch S is closed.
10 Ω
90 Ω 109 Part 2 of 2
What can you do if you need a 5 Ω resistor?
1. 2 in series with 2 in parallel
2. 1 in series with 3 in parallel
3. 3 in series
4. 4 in series
5. 2 in series S
90 Ω 10 Ω R E i
Find the value of R. 6. 2 in parallel
7. 3 in parallel
8. 4 in parallel
9. None of these Holt SF 20Rev 42
28:04, highSchool, multiple choice, > 1 min,
normal. Holt SF 20Rev 47
28:04, highSchool, numeric, > 1 min, wordingvariable. Part 1 of 2
You can obtain only four 20 Ω resistors from
the stockroom.
How can you achieve a resistance of 50 Ω
under these circumstances? Part 1 of 2
The power supplied to the circuit shown in
the ﬁgure is 4.00 W.
10.0 Ω 1. 2 in series with 2 in parallel 4.0 Ω
5. 0 Ω
3.0 Ω 2. 1 in series with 3 in parallel
3. 3 in series
4. 4 in series
5. 2 in series
6. 2 in parallel
7. 3 in parallel
8. 4 in parallel
9. None of these 3. 0 Ω E a) Find the equivalent resistance of the circuit.
Part 2 of 2
b) Find the potential diﬀerence across the
battery.
Tetrahedron Resistors 02
28:04, highSchool, numeric, > 1 min, normal. Chapter 28, section 4, Resistance: Series/Parallel Combinations 7Ω Ω
21 7Ω
A 21 2.5 Ω A tetrahedron (a four cornered, six edged,
four sided body with congruent isosceles triangles as each side) has resistors on each of its
edges and electric potential is across two of its
corners, A and B , as shown in the ﬁgure.
Let: Ii be the current through resistor Ri and
Vi be the potential across resistor Ri .
Hint: Simplify by using symmetry observations before applying straightforward circuit
analysis. 14 Ω Ω
B What is the resistance between A and B
using the given resistances? 110 Chapter 28, section 5, Potential Diﬀerence Between Two Points
Battery with internal resistance
28:05, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The internal resistance r of a battery with
emf E is connected to a load resistor with
resistance R.
100 Ω
I
10 V A 10 Ω B internal
resistance Find the potential diﬀerence VBA = VA −
VB .
Part 2 of 2
What is the power P dissipated by the load
resistor R?
1. P = E
r+R 2 R 2. P = r E 2
E2
r
E2
4. P =
r+R 3. P = 5. P = E
r+R 2 6. P = (r + R) E 2
7. P = R E 2
8. P = E
R E2
r
R
E2
10. P =
rR
9. P = 2 r r 111 Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
Five Bulbs 01
28:06, highSchool, multiple choice, > 1 min,
ﬁxed.
Consider the following circuit containing
identical bulbs A, B , C , D, and E respectively. Denote the potentials across bulbs as
VA , VB , VC , VD , and VE . D E
C
B In the ﬁgure below consider the case where
switch S1 is closed and switch S2 is open.
c
30
Ω
Ω
10
a 20 E Ω S2 50 V 2. VA = VB = VC = VD = VE
3. VA = VD = VE > VB > VC
4. VA = VD = VE > VB = VC
5. VB = VC > VA = VD = VE
6. VA = VB > VA = VD = VE
7. VA = VC > VB > VD = VE
8. VC > VB > VA > VD > VE
9. VE = VD > VA > VB = VC
10. VA = VB = VC > VD > VE
Four Resistors 01 shortened
28:06, highSchool, numeric, > 1 min, normal.
Part 1 of 2 40 Ω
S1 d Part 2 of 2
Now consider the case where switch S2 is also
closed, so
c
30
Ω
Ω
10 20 Ω b S2 0Ω 4 50 V d Rank the potentials across the bulbs.
1. VA = VB = VC > VD = VE b Find the current in the path from a to c. a
A 112 S1 Find the current in the path from a to c
through the 10 Ω resistor.
Four Resistors 02
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
Four resistors connected to a battery are
shown in the ﬁgure below. The switch S1 is
closed and switch S2 is left open.
c
170
Ω
57 Ω
a
b
S2
170
Ω
57 Ω
113 V d S1 What is the magnitude of the potential difference Vcd ? Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
Part 2 of 4
The potential diﬀerence Vcd is Four Resistors 04
28:06, highSchool, numeric, > 1 min, normal. 1. positive. Part 1 of 2
Four resistors are connected as shown in
the ﬁgure.
c
50 Ω
10 Ω
a
b
Ω
70 Part 3 of 4
The switch S2 is closed.
c
57 Ω 170 S2 Ω 113 V 170 30 Ω 2. negative. a 113 Ω
b 57 Ω S1 d Find the resistance between points a and b. S1 d 90 V After closing the switch S2 , what is the
potential diﬀerence Vad ? Part 2 of 2
What is the current through the 50 Ω resistor? Part 4 of 4
How much current passes through the switch
S2 when it is closed? Four Resistors 06
28:06, highSchool, multiple choice, > 1 min,
ﬁxed. Four Resistors 03
28:06, highSchool, numeric, > 1 min, normal. Part 1 of 2
All the bulbs in the ﬁgure below have the
same resistance R. The switch S is initially
closed. Part 1 of 2
Four resistors are connected as shown in
the ﬁgure.
c 90 V iB b 30 Ω a S Ω
50 Ω 10 iD 0Ω 7 d iA
V S1 Find the resistance between points a and b.
Part 2 of 2
What is the current in the 30 Ω resistor? iC i0
If bulb B is removed from the circuit, i.e.,
the switch S is opened, what happens to the
current through
1) the battery,
2) bulb A, and
3) bulb D;
i.e., the brightness of bulb A, and bulb D? Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
Hint: You may ﬁnd it helpful to work out the
currents through bulb A and bulb D, and the
battery for both cases by using V = 1 volt
and R = 1 Ω.
1. iA decreases, iD remains the same, ibattery
decreases
2. iA increases, iD increases, ibattery increases
3. iA increases, iD increases, ibattery decreases
4. iA increases, iD remains the same, ibattery
increases
5. iA remains the same, iD increases, ibattery
increases
6. iA increases, iD increases, ibattery remains
the same
7. iA increases, iD decreases, ibattery decreases
8. iA decreases, iD decreases, ibattery decreases
9. iA remains the same, iD remains the same,
ibattery remains the same
10. iA decreases, iD decreases, ibattery remains
the same 114 pens to the current through
1) the battery,
2) bulb A, and
3) bulb D;
i.e., the brightness of bulb A, and bulb D?
1. iA increases, iD remains the same, ibattery
increases
2. iA increases, iD increases, ibattery decreases
3. iA increases, iD increases, ibattery increases
4. iA decreases, iD remains the same, ibattery
decreases
5. iA remains the same, iD increases, ibattery
increases
6. iA increases, iD increases, ibattery remains
the same
7. iA increases, iD decreases, ibattery decreases
8. iA decreases, iD decreases, ibattery decreases
10. iA remains the same, iD remains the same,
ibattery remains the same Part 2 of 2 Four Resistors 07
28:06, highSchool, multiple choice, > 1 min,
ﬁxed. iD All the bulbs in the ﬁgure below above
have the same resistance R. The switch S is
initially closed.
S
iC iA
V iB i0
If a wire is added to the circuit, what hap Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules 115 9. iA remains the same, iD remains the same,
ibattery remains the same
10. iA decreases, iD decreases, ibattery remains
the same iD
S
iB
iA
V iC i0
If bulb B is removed from the circuit, i.e.,
the switch S is opened, what happens to the
current through
1) the battery,
2) bulb A, and
3) bulb D;
i.e., the brightness of bulb A, and bulb D?
You may ﬁnd it helpful to work out the currents through bulb A and bulb D, and the
battery for both cases by using V = 1 volt
and R = 1 Ω.
1. iA decreases, iD remains the same, ibattery
decreases
2. iA increases, iD increases, ibattery increases
3. iA increases, iD increases, ibattery decreases
4. iA increases, iD remains the same, ibattery
increases
5. iA remains the same, iD increases, ibattery
increases
6. iA increases, iD increases, ibattery remains
the same
7. iA increases, iD decreases, ibattery decreases
8. iA decreases, iD decreases, ibattery decreases Four Resistors 08
28:06, highSchool, multiple choice, < 1 min,
ﬁxed.
All the bulbs in the ﬁgure below have the
same resistance R. The switch S is initially
closed. iD
S
iB
iA
V iC i0
If bulb B is removed from the circuit, i.e.,
the switch S is opened, what happens to the
currents through
1) the battery,
2) bulb A, and
3) bulb D;
Notice that in the diagram the current
through the battery, ibattery , is labeled as i0 .
Hint: You may ﬁnd it helpful to work out the
currents through bulb A , bulb D , and the
battery for both cases by using V = 1 volt
and R = 1 Ω.
1. iA decreases, iD remains the same, ibattery
decreases
2. iA increases, iD increases, ibattery increases
3. iA increases, iD increases, ibattery decreases
4. iA increases, iD remains the same, ibattery
increases Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
5. iA remains the same, iD increases, ibattery
increases
6. iA increases, iD increases, ibattery remains
the same
7. iA increases, iD decreases, ibattery decreases
8. iA decreases, iD decreases, ibattery decreases 3.
4.
5.
6.
7.
8. i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0
i0 116 5
2
9
=
2
= =5
=3
=1
10
3
2
=
5
1
=
2
= 9. iA remains the same, iD remains the same,
ibattery remains the same 9. 10. iA decreases, iD decreases, ibattery remains
the same 10. Four Resistors 10
28:06, highSchool, multiple choice, > 1 min,
ﬁxed. Hewitt CP9 23 07
28:06, highSchool, multiple choice, < 1 min,
ﬁxed. All the bulbs in the ﬁgure below above have
the same resistance R. How does the sum of the currents ﬂowing
through the branches of a sample parallel circuit compare to the current that ﬂows through
the voltage source?
1. The sum of currents in the branches is bigger than the current of the voltage source. iD
S
iB 2. The sum of currents in the branches is
equal to the current of the voltage source. iA
V iC
i0 i0
, where i0 is the current
i0
through the battery when the switch is closed
and i0 is the current through the battery when
the switch is open.
Determine i0
9
=
i0
10
i
2
2. 0 =
i0
3
1. 3. The sum of currents in the branches
is smaller than the current of the voltage
source.
4. It cannot be determined.
Hewitt CP9 23 E40
28:06, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 4
In the circuit shown, the light bulbs are
identical. Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules 117 3. B is brighter.
4. A is brighter.
A B C
S V Which bulb is brightest?
1. A
2. B
3. C
4. A, B and C have the same brightnesses.
5. A and B are brighter than C .
6. It can’t be determined unless the voltage
of the power supply is known.
Part 2 of 4
Which lightbulb draws the most current?
1. C
2. B
3. A
4. A, B and C have the same current. 5. Both A and B turn oﬀ.
6. Can’t determine unless we know the voltage of the power supply.
Part 4 of 4
What will happen if bulb C is unscrewed?
1. A short circuit occurs and the circuit
catches ﬁre.
2. A and B have same brightnesses.
3. B is brighter.
4. C is brighter.
5. A is brighter.
6. Can’t determine unless we know the voltage of the power supply.
Holt SF 20D 01
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 6
Consider the circuit in the ﬁgure.
2. 0 Ω
8.0 Ω
10 Ω
5. 0 Ω 5. A and B have more current than C .
6. It can’t be determined unless the voltage
of the power supply is known.
Part 3 of 4
What will happen if bulb A is unscrewed?
1. A short circuit occurs and the circuit
catches ﬁre.
2. C is brighter. S 10 Ω
14.0 V 15 Ω a) Find the current in the 5.0 Ω resistor.
Part 2 of 6
b) Find the potential diﬀerence across the
2.0 Ω resistor.
Part 3 of 6
c) Find the potential diﬀerence across the
8.0 Ω resistor. Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
Part 4 of 6
d) Find the potential diﬀerence across either
of the 10 Ω resistors.
Part 5 of 6
e) Find the current in either one of the 10 Ω
resistors.
Part 6 of 6
f) Find the potential diﬀerence across the
15 Ω resistor.
Holt SF 20Rev 25
28:06, highSchool, numeric, > 1 min, normal.
Part 1 of 3
Consider the circuit in the ﬁgure.
5. 5 Ω 8. 5 Ω 2. 5 Ω 12 V Find the current in the 2.5 Ω resistor.
Part 2 of 3
Find the current in the 8.5 Ω resistor.
Part 3 of 3
Find the current in the 5.5 Ω resistor. 6.0 Ω
3.0 Ω
6.0 Ω
4.0 Ω
2. 0 Ω
12.0 Ω
18.0 V 3.0 Ω Find the current in the 2.0 Ω resistor.
Part 2 of 4
Find the potential diﬀerence across the 2.0 Ω
resistor.
Part 3 of 4
Find the potential diﬀerence across the 12.0
Ω resistor.
Part 4 of 4
Find the current in the 12.0 Ω resistor.
Holt SF 20Rev 36
28:06, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 4
Three small lamps are connected to a 9 V
battery, as shown in the ﬁgure. Assume the
battery is ideal (has no internal resistance and
given in the ﬁgure) and the connecting wires
have no resistance. Unlike most real bulbs,
the resistances (given in the ﬁgure) of the
bulbs do not vary. The switch S is closed. Holt SF 20Rev 26
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
Consider the circuit in the ﬁgure. 118 S
2Ω
4. 5 Ω
9V 3Ω a) What is the equivalent resistance of this
circuit? Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
30.0 Ω Part 2 of 4
b) What is the total current of this circuit?
Part 3 of 4
c) What is the current in the 3 Ω bulb? Part 5 of 5
e) Calculate the potential diﬀerence across
the ﬁrst resistor.
Holt SF 20Rev 43
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 6
Four resistors are connected to a battery
with a terminal voltage of 12.0 V, as shown in
the ﬁgure. Part 3 of 6
c) Find the current in the 30.0 Ω resistor.
Part 4 of 6
d) Find the power dissipated by the 50.0 Ω
resistor.
Part 5 of 6
e) Find the power dissipated by the 20.0 Ω
resistor.
Part 6 of 6
f) Find the power dissipated by the 90.0 Ω
resistor.
Holt SF 20Rev 46
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Consider the following circuit.
5. 0 Ω
3 .0 Ω
3.0 Ω 4. 0 Ω 2 .0 Ω 4.0 Ω Part 4 of 5
d) Calculate the current in the second resistor. Part 2 of 6
b) Find the current in the battery. 10.0 Ω Part 3 of 5
c) Calculate the current in the ﬁrst resistor. 12.0 V a) Find the equivalent resistance of the circuit. 10.0 Ω Part 2 of 5
b) Calculate the current in the third resistor. 20.0 Ω 28 V Part 1 of 5
A 30.0 Ω resistor is connected in parallel to
a 15.0 Ω resistor. These are joined in series to
a 5.00 Ω resistor and a source with a potential
diﬀerence of 30.0 V.
a) Calculate the equivalent resistance. 50.0 Ω 90.0 Ω Part 4 of 4
d) What is the potential diﬀerence across the
4.5 Ω bulb?
Holt SF 20Rev 38
28:06, highSchool, numeric, > 1 min, wordingvariable. 119 3.0 Ω a) Find the equivalent resistance.
Part 2 of 2 Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
b) Find the current in the 5 Ω resistor.
Resistance Circuit 05
28:06, highSchool, numeric, > 1 min, normal.
Part 1 of 3
In the circuit below R1 = R2 = R, R3 =
2 R, and R4 = 4 R.
C
R3
R1
A i1
R2
E I5 i2 R4 Seven Resistors
28:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Consider the circuit in the ﬁgure.
6.0 Ω
3.0 Ω
6.0 Ω
4.0 Ω
2. 0 Ω
12.0 Ω i4
D Find RAB when R = 1 Ω .
Part 2 of 3
i3
Find the ratio .
i4
i3
1.
=2
i4
i3
2.
=1
i4
i3
=3
3.
i4
i3
=4
4.
i4
i3
5.
=8
i4
i3
1
6.
=
i4
2
i3
1
7.
=
i4
4
i3
1
8.
=
i4
8
i3
1
9.
=
i4
3
i3
10.
=0
i4
Part 3 of 3
Let I = 5 A.
Find i5 . B i3 120 18.0 V 3.0 Ω Find the current in the 2.0 Ω resistor.
Part 2 of 3
Find the potential diﬀerence across the 2.0 Ω
resistor.
Part 3 of 3
Find the current in the 12.0 Ω resistor.
Two Loop Circuit 01
28:06, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Consider the circuit shown below.
There are three resistors, r1 , r2 , and R; and
two emf’s, E1 and E2 . The directions of the
currents i1 , i2 , and i are shown in the ﬁgure.
B E1 r1 A i1
R F C E2 i
r2 E D i2
Apply Kirchhoﬀ’s rules.
What equation does the loop ABCDA
yield? Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
1. E1 − E2 + i2 r2 − i1 r1 = 0 B E1 2. E1 − E2 − i2 r2 − i1 r1 = 0 C 5. E1 + E2 − i2 r2 − i1 r1 = 0 7. E1 + E2 + i2 r2 − i1 r1 = 0 i
r2 D 2. E1 − E2 − i2 r2 − i1 r1 = 0 9. E1 − E2 − i1 r2 + i2 r1 = 0 3. E1 − E2 − i2 r2 + i1 r1 = 0 10. E1 − E − i1 r2 − i2 r1 = 0
Part 2 of 2
Hint: From symmetry, one expects i1 = i2 )
Let E1 = E2 = 10 V, r1 = r2 = 1 Ω, and
R = 3 Ω.
10 V
1Ω
B
A
i1 4. E1 − E2 + i2 r2 + i1 r1 = 0
5. E1 + E2 − i2 r2 − i1 r1 = 0
6. E1 + E2 + i2 r2 + i1 r1 = 0
7. E1 + E2 + i2 r2 − i1 r1 = 0
8. E1 + E2 − i2 r2 + i1 r1 = 0 E i
1Ω E2 E 1. E1 − E2 + i2 r2 − i1 r1 = 0 8. E1 + E2 − i2 r2 + i1 r1 = 0 C A i2
Apply Kirchhoﬀ’s rules. What equation
does the loop BADCB yield? 6. E1 + E2 + i2 r2 + i1 r1 = 0 10 V R F 4. E1 − E2 + i2 r2 + i1 r1 = 0 3Ω r1
i1 3. E1 − E2 − i2 r2 + i1 r1 = 0 F 121 D i2
Find the current i.
Two Loop Circuit 02
28:06, highSchool, numeric, > 1 min, normal.
Part 1 of 3
Consider the circuit shown below. There
are three resistors, r1 , r2 , and R; and two
emf’s, E1 and E2 .
The directions of the currents i1 , i2 , and i
are shown in the ﬁgure. 9. E1 − E2 − i1 r2 + i2 r1 = 0
10. E1 − E2 − i1 r2 − i2 r1 = 0
Part 2 of 3
What equation does the loop DCFED yield?
1. −E2 + i2 r2 + i R = 0
2. −E2 − i2 r2 − i R = 0
3. −E2 − i2 r2 + i R = 0
4. E2 − i2 r2 + i R = 0
5. E2 − i2 R + i r2 = 0
6. E2 + i2 R − i r2 = 0 Chapter 28, section 6, Complicated Circuits: Kirchoﬀ’s Rules
7. −E2 − i2 R − i r2 = 0 9. E1 + i1 R1 + i3 R3 + E2 − i4 R4 − i2 R2 = 0 . 8. −E2 + i2 R + i r2 = 0 10. E1 − i1 R1 − i3 R3 + E2 + i4 R4 + i2 R2 = 0 . 9. E2 + i2 r2 − i1 R = 0 Part 2 of 3
Choose the correct relationships among the
currents. 10. E2 − i2 r2 − i1 R = 0
Part 3 of 3
Let: E1 = E2 = 10 V, r1 = r2 = 1 Ω, and
R = 3 Ω.
Hint: From symmetry, one expects i1 = i2 .
Find the current i. A1 :
A2 :
B1 :
B2 :
B3 :
B4 :
B5 : Two loops
28:06, highSchool, multiple choice, > 1 min,
normal. R2 122 Part 1 of 3
E1
A
B i 1 + i3 = i5 ;
i 1 = i3 + i5 ;
i1 > i2 and i3
i1 < i2 and i3
i1 > i2 and i3
i1 = i2 and i3
i1 < i2 and i3 R1 1. A1 and B1. i1 2. A1 and B2. 3. A1 and B3. 4. A1 and B4. 5. A1 and B5. i3
E2
For the loop ABCDEF A, the corresponding loop equation is given by 6. A2 and B1. 7. A2 and B2. 1. E1 + i1 R1 + i3 R3 + E2 + i4 R4 + i2 R2 = 0 . 8. A2 and B3. 2. E1 − i1 R1 − i3 R3 + E2 − i4 R4 − i2 R2 = 0 . 9. A2 and B4. 3. E1 + i1 R1 + i3 R3 −E2 + i4 R4 + i2 R2 = 0 . 10. A2 > i4 ;
> i4 ;
< i4 ;
= i4 ;
< i4 . and B5. i2
R5 F C i5
R4 E D R3 i4 4. E1 − i1 R1 − i3 R3 −E2 − i4 R4 − i2 R2 = 0 .
5. E1 + i1 R1 − i3 R3 −E2 − i4 R4 + i2 R2 = 0 .
6. E1 − i1 R1 + i3 R3 −E2 + i4 R4 − i2 R2 = 0 .
7. E1 + i1 R1 + i3 R3 −E2 − i4 R4 − i2 R2 = 0 .
8. E1 − i1 R1 − i3 R3 −E2 + i4 R4 + i2 R2 = 0 . Part 3 of 3
Given
E1 = E 2 = E = 1 V ,
R1 = R 2 = R 3 = R 4 = R 5 = R = 2 Ω ,
ﬁnd the value of i5 . Notice that the setup of
the left loop is symmetric to the setup of the
right loop. Chapter 28, section 7, RC Circuits 123 itor is steady.
Bulbs in a Circuit 03
28:07, highSchool, multiple choice, < 1 min,
ﬁxed. 3. The bulb is on and is bright.
4. The current in the circuit is steady. Part 1 of 2
Unlike most real bulbs, the resistance of the
bulb in the questions below does not change as
the current through it changes. A capacitor, a
bulb, and a switch are in the circuit as shown
below.
S
R C The switch is initially open as shown in the
above diagram, and the capacitor is charged.
S
R C 5. None of these is correct.
Bulbs in a Circuit 04
28:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Unlike most real bulbs, the resistance of the
bulb in this question does not change as the
current through it changes. A capacitor, a
bulb, and a switch are in the circuit as shown
below.
S
R C The switch is initially open as shown in the
above diagram, and the capacitor is charged. Which of the following correctly describes
what happens to the bulb when the switch is
closed? S
R 1. The bulb is dim and remains dim.
2. At ﬁrst the bulb is dim and it gets brighter
and brighter until the brightness levels oﬀ. C Which of the following correctly describes
what happens to the bulb when the switch is
closed? 3. The bulb is bright and remains bright.
1. The bulb is dim and remains dim.
4. At ﬁrst the bulb is bright and it gets
dimmer and dimmer until it goes oﬀ. 2. At ﬁrst the bulb is dim and it gets brighter
and brighter until the brightness levels oﬀ. 5. None of these is correct.
3. The bulb is bright and remains bright.
Part 2 of 2
Which correctly describes what happens after
the switch has remained closed for a long
time? 4. At ﬁrst the bulb is bright and it gets
dimmer and dimmer until it goes oﬀ.
5. None of these is correct. 1. The bulb is permanently oﬀ.
2. The potential diﬀerence across the capac Charging RC Circuit
28:07, highSchool, multiple choice, > 1 min, Chapter 28, section 7, RC Circuits
ﬁxed. 124
R3 The switch S has been in position b for a
long period of time.
R3 C R2 E R1
C R2
R1 Sb
a Sb
E a When the switch is moved to position “a”,
ﬁnd the characteristic time constant.
1. τ = R1 C When the switch is moved to position “a”,
ﬁnd the characteristic time constant.
1. τ = R1 C
2. τ = R2 C
3. τ = 1 R1 C
1
4. τ =
R2 C
5. τ = (R1 + R2 ) C
1
(R 1 + R 2 ) C
R1 + R 2
7. τ =
C
2
2
8. τ =
(R 1 + R 2 ) C
6. τ = 9. τ =
10. τ = √ 2. τ = R2 C
3. τ = 1 R1 C
1
4. τ =
R2 C
5. τ = (R1 + R2 ) C 1
(R 1 + R 2 ) C
R1 + R 2
7. τ =
C
2
2
8. τ =
(R 1 + R 2 ) C
6. τ = 9. τ =
10. τ = √ R1 R2 C
1
R 1 R2 C R 1 R2 C Part 2 of 2
3.3 MΩ 1
R 1 R2 C Discharging RC Circuit
28:07, highSchool, multiple choice, > 1 min,
normal.
Part 1 of 2
The switch S has been in position b for a
long period of time. 1.3 µF 2 MΩ
1.1 MΩ Sb
1.2 V a S has been left at position “a” for a long
time. It is then switched from “a” to “b” at
t = 0.
Determine the energy dissipated through
the resistor R2 alone from t = 0 to t = ∞.
Series RC Circuit 07S
28:07, highSchool, multiple choice, > 1 min, Chapter 28, section 7, RC Circuits 125 normal.
Part 1 of 2
Consider the RC circuit shown. The emf
of the battery is V , the resistance R, and the
capacitance C . The capacitor is uncharged. C R
V Series rc circuit
28:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Consider the RC circuit shown. The emf
of the battery is V , the resistance R, and the
capacitance C .
C
R S
Consider the following statements.
A1: I = 0
V
A2: I =
R
V −1/RC
A3: I = e
R
B1: VC = 0
B2: VC = V
B3: VC = V e−1/RC
Immediately after the switch is closed, the
current, I , and the potential across the capacitor, VC , are respectively given by
1. A2, B1 E i Consider the following statements.
A1: I = 0
V
A2: I =
R
V
A3: I = e−1/(RC )
R
B1: VC = 0
B2: VC = V
B3: VC = V e−1/(RC )
After S has been closed for a very long
time, the current through R and the potential
across the capacitor are given respectively by: 2. A2, B2 1. A2, B1 3. A2, B3 2. A2, B2 4. A1, B1 3. A2, B3 5. A1, B2 4. A1, B1 6. A1, B3 5. A1, B2 7. A3, B1 6. A1, B3 8. A3, B2 7. A3, B1 9. A3, B3 8. A3, B2 Part 2 of 2
Find the time for the plate charge to reach
one third of its maximum value if R = 1 Ω,
C = 1 µf, V = 10 V. S 9. A3, B3 Chapter 28, section 9, Household Wiring and Electrical Safety
Holt SF 20Rev 48
28:09, highSchool, numeric, > 1 min, normal.
Your toaster oven and coﬀeemaker each dissipate 1200 W of power. You have a 120 V
line in your kitchen.
For what current must the circuit breaker
be rated for you to operate both of these
appliances at the same time?
Holt SF 20Rev 49
28:09, highSchool, numeric, > 1 min, normal.
Part 1 of 3
An electric heater is rated at 1300 W, a
toaster is rated at 1100 W, and an electric
grill is rated at 1500 W. The three appliances
are connected in parallel across a 120 V emf
source.
Find the current in the heater.
Part 2 of 3
Find the current in the toaster.
Part 3 of 3
For what current must the circuit breaker be
rated for you to operate all of these appliances
at the same time? 126 Chapter 29, section 1, Magnetic Fields and Forces
Conceptual 17 02
29:01, highSchool, numeric, > 1 min, normal. 127 6. downward
7. There is no force. Part 1 of 4
The strength of Earth’s magnetic ﬁeld B
at the equator is approximately equal to
5 × 10−5 T, where T stands for tesla, the
unit of magnetic ﬁeld. The force on a charge q
moving in a direction perpendicular to a magnetic ﬁeld is given by F = q v B , where v is
the speed of the particle. The direction of the
force is given by the righthand rule. Suppose
you rub a balloon in your hair and your head
acquires a static charge of 3 × 10−9 C.
If you are at the equator and driving west at
a speed of 30 m/s, what is the strength of the
magnetic force on your head due to Earth’s
magnetic ﬁeld?
Part 2 of 4
What is the direction of that magnetic force? Part 4 of 4
If you are driving east, how fast would you
have to drive in order for the magnetic force
on your head to equal 200 N (probably enough
to knock you over)?
Conceptual 17 Q20
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A positively charged particle passes
through a laboratory traveling in an easterly
direction. There are both electric and magnetic ﬁeld in the room and their eﬀects on the
charged particle cancel.
If the electric ﬁeld points upward, what
must be the direction of the magnetic ﬁeld? 1. east 1. east 2. west 2. west 3. north 3. south 4. south 4. north 5. upward 5. upward 6. downward 6. downward Part 3 of 4
If you are at the equator and driving north
at a speed of 30 m/s, what is direction of the
magnetic force on your head?
1. east
2. west Conceptual 24 Q04
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
When you go in to have an MRI done, the
technician always tells you to remove your
watch, pens, and other metal objects from
your pockets.
Why is this request made? 3. north
4. south
5. upward 1. There is a strong magnetic ﬁeld in the
MRI machine.
2. There is a strong electric ﬁeld in the MRI Chapter 29, section 1, Magnetic Fields and Forces
machine.
3. There is a weak electric ﬁeld in the MRI
machine. 128 (for example, a baseball with some electrons
removed) to the east, what is the direction of
the magnetic force on the object?
1. downward Conceptual 24 Q06
29:01, highSchool, multiple choice, < 1 min,
ﬁxed. 2. toward the east
3. toward the west If all atoms have electrons that are in motion about an atom, why aren’t all materials
magnetic?
1. The net magnetic ﬁeld created by ordinary materials is zero.
2. Ordinary materials do not create magnetic ﬁelds.
3. Random motion of electrons does not
create magnetic ﬁelds.
Conceptual Q16 12
29:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. upward
Conceptual Q16 16
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The magnetic ﬁeld at the equator points
north.
If you throw a negatively charged object
(for example, a baseball with some electrons
removed) to the east, what is the direction of
the magnetic force on the object?
1. upward
2. toward the east The Greeks had a legend that there was an
island in the Mediterranean Sea made entirely
of lodestone. They used this story as an
argument that ships should not be built with
iron nails.
Because of this legend, why would they not
use iron nails?
1. They had strong magnetic attraction.
2. They were not strong enough. 3. toward the west
4. downward
Conceptual Q16 19
29:01, highSchool, numeric, < 1 min, normal.
A small bar magnet pulls on a larger one
with a force of 100 newtons.
What is the magnitude of the force the
larger one exerts on the smaller one? 3. They were expensive.
4. They were rarely found.
Conceptual Q16 15
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The magnetic ﬁeld at the equator points
north.
If you throw a positively charged object Field Direction
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The direction of the magnetic ﬁeld in a
certain region of space is determined by ﬁring
a test charge into the region with its velocity
in various directions in diﬀerent trials.
The ﬁeld direction is Chapter 29, section 1, Magnetic Fields and Forces
1. one of the direction of the velocity when
the magnetic ﬁeld is zero.
2. the direction of the velocity when the
magnetic force is a maximum.
3. the direction of the magnetic force.
4. perpendicular to the velocity when the
magnetic force is zero. 129 magnetic ﬁeld.
3. Sometimes a magnetic ﬁeld disappears
when an electron is placed in it.
4. If the velocity of an electron is greater
than a critical value, a magnetic ﬁeld cannot
exert any force on the electron.
5. Away from the Earth an electron does not
feel any magnetic force. 5. None of these
Hewitt CP9 24 E05
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is it inadvisable to make a horseshoe
magnet from a ﬂexible material?
1. A ﬂexible material is not easily magnetized.
2. A ﬂexible material is easily loses its magnetism. Hewitt CP9 24 E09
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why will a magnet attract an ordinary nail
or paper clip, but not a wooden pencil?
1. A nail or paper clip has magnetic domains
which a wooden pencil does not have.
2. A nail or paper clip has a magnet inside
which a wooden pencil does not have. 3. A ﬂexible material cannot be easily made
into a horseshoe shape. 3. A magnet can generate electromagnetic
waves which can be absorbed by a nail but
not by a pencil. 4. The poles of the magnet attract each
other and will cause the magnet to bend. 4. A nail or paper clip has molecular circuits
which a wooden pencil does not have. 5. None of these is correct.
Hewitt CP9 24 E08
29:01, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 24 E10
29:01, highSchool, multiple choice, < 1 min,
ﬁxed. “An electron always experiences a force in
an electric ﬁeld, but not always in a magnetic
ﬁeld.” Defend this statement. A friend tells you that a refrigerator door,
beneath its layer of white painted plastic, is
made of aluminum.
How could you check to see if this is true
(without any scraping)? 1. An electron always has a charge in an
electric ﬁeld, but not always in a magnetic
ﬁeld. 1. Burn the refrigerator door and then analyze the remains with chemical reagents to
ﬁnd if aluminum is present. 2. An electric ﬁeld always acts on charged
particles. The magnetic force vanishes when
the velocity of the electron is parallel to the 2. Apply a small magnet to the door. If
it sticks, your friend might be right because
aluminum is magnetic. If it doesn’t stick, Chapter 29, section 1, Magnetic Fields and Forces
your friend might be wrong.
3. Apply a small magnet to the door. If it
sticks, your friend is wrong because aluminum
is not magnetic. If it doesn’t stick, your friend
might be right, (but not necessarily).
4. It cannot be checked without scraping the
painted plastic.
Hewitt CP9 24 E21
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why will a magnet placed in front of a
television picture tube distort the picture?
(Do NOT try this with a color set!) 130 strong magnet? If not, why not? If so, does
it exert as much force on the magnet as the
magnet exerts on it?
1. No force; the paper clip is not itself a
magnet.
2. A smaller force; the magnetic ﬁeld of the
paper clip is much weaker than the magnetic
ﬁeld of the strong magnet.
3. Equal force; Newton’s third law applies
here.
4. It depends on the material in the magnet.
5. None of these 1. The magnetic ﬁeld will distort the TV
signal.
2. The magnetic ﬁeld will magnetize the
materials in the TV screen.
3. Moving electrons in the TV set are deﬂected from their paths by magnetic ﬁeld.
4. The iron parts in the TV set are magnetized and thus do not work properly. Hewitt CP9 24 E27
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Can an electron at rest in a magnetic ﬁeld
be set into motion by the magnetic ﬁeld?
What if it were at rest in an electric ﬁeld?
1. yes; no
2. no; yes 5. None of these
3. yes for both
Hewitt CP9 24 E22
29:01, highSchool, numeric, < 1 min, normal.
Magnet A has twice the magnetic ﬁeld
strength of magnet B (at equal distance) and
at a certain distance pulls on magnet B with
a force of 50 N.
With how much force, then, does magnet B
pull on magnet A?
Hewitt CP9 24 E24
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A strong magnet attracts a paper clip to
itself with a certain force.
Does the paper clip exert a force on the 4. no for both
5. It depends on the intensity of the ﬁelds,
which is not provided in the problem.
6. None of these
Hewitt CP9 24 E29
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A magnetic ﬁeld can deﬂect a beam of electrons, but it cannot do work on the electrons
to change their speed.
Why? Chapter 29, section 1, Magnetic Fields and Forces
1. When a magnetic ﬁeld does work on the
electrons, the work is changed into light instead of increasing the energy of electrons. 131 2. a massive object at rest
3. a moving electric charge 2. A magnetic ﬁeld can do work on the
electrons to either increase or decrease the
speed of the electrons; however, with timeaveraging their speeds remain constant.
3. Moving electrons change the magnetic
ﬁeld such that it cannot do work on the electrons.
4. The direction of a magnetic force is always
perpendicular to the velocity of an electron,
so it cannot do work on the electron.
Hewitt CP9 24 E30
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Two charged particles are projected into a
magnetic ﬁeld that is perpendicular to their
initial velocities.
If the charges are deﬂected in opposite directions, what does this tell you about them?
(Ignore the interaction between these two particles.)
1. They have opposite charges if their initial
velocities are in the same direction.
2. Their velocities have opposite directions.
3. One particle is an electron and the other
is a positive ion.
4. One particle comes from nature; the other
is manmade.
Hewitt CP9 24 R07
29:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What produces a magnetic ﬁeld?
1. a nonuniform but timeconstant electric
ﬁeld 4. a moving atom
Holt SF 21A 01
29:01, highSchool, numeric, < 1 min, wordingvariable.
A proton moves perpendicularly to a magnetic ﬁeld that has a magnitude of 4.20 × 10−2
T.
The charge on a proton is 1.60×10−19 .
What is the speed of the particle if the
magnitude of the magnetic force on it is 2.40 ×
10−14 N?
Holt SF 21A 02
29:01, highSchool, numeric, < 1 min, wordingvariable.
A proton traveling to the right along the
xaxis enters a region where there is a magnetic ﬁeld of magnitude 2.5 T directed upward
along the y axis.
The charge on a proton is 1.60×10−19 .
If the proton experiences a force of 3.2 ×
10−12 N, ﬁnd its speed.
Holt SF 21A 03
29:01, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
An electron in an electron beam experiences a downward force of 2.0 × 10−14 N while
traveling in a magnetic ﬁeld of 8.3 × 10−2 T
west.
The charge on a proton is 1.60×10−19 .
a) What is the magnitude of the velocity?
Part 2 of 2
b) What is its direction?
1. North
2. East Chapter 29, section 1, Magnetic Fields and Forces
3. South 1. North 4. West 2. South 5. None of these 132 3. West Holt SF 21A 04
29:01, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A uniform 1.5 T magnetic ﬁeld points
north. If an electron moves vertically downward (toward the ground) with a speed of
2.5 × 107 m/s through this ﬁeld.
The charge on a proton is 1.60×10−19 .
a) What is the magnitude of the force acting
on it?
Part 2 of 2
b) What is the direction of the force?
1. North
2. South
3. West
4. East
5. None of these
Holt SF 21A 05
29:01, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A proton moves straight upward (away
from the ground) through a uniform magnetic ﬁeld that points from east to west and
has a magnitude of 2.5 T.
The charge on a proton is 1.60×10−19 .
a) If the proton moves with a speed 1.5 × 107
m/s through this ﬁeld, what is the magnitude
of the force acting on it?
Part 2 of 2
b) What is its direction? 4. East
5. None of these
Holt SF 21A 06
29:01, highSchool, numeric, < 1 min, normal.
An alpha particle (the nucleus of a helium atom, carrying a charge of 3.2 × 10−19 C
moves at 5.5 × 107 m/s at a right angle to a
magnetic ﬁeld.
The charge on a proton is 3.2 × 10−19 C.
If the particle experiences a force of
1.5 × 10−14 N due to the magnetic ﬁeld, what
is the magnitude of the magnetic ﬁeld?
Holt SF 21Rev 30
29:01, highSchool, numeric, < 1 min, wordingvariable.
A duck ﬂying due east passes over Atlanta, where the magnetic ﬁeld of the Earth is
5.0 × 10−5 T directed north. The duck has a
positive charge of 4.0 × 10−8 C.
If the magnetic force acting on the duck is
3.00 × 10−11 N upward, what is the magnitude
of the duck’s velocity?
Holt SF 21Rev 31
29:01, highSchool, numeric, < 1 min, wordingvariable.
A proton moves eastward in the plane of
Earth’s magnetic equator so that its distance
from the ground remains constant.
The acceleration of gravity is 9.81 m/s2
and the charge on a proton is 1.60×10−19 .
What is the speed of the proton if Earth’s
magnetic ﬁeld points north and has a magnitude of 5.0 × 10−5 T?
Holt SF 21Rev 34 Chapter 29, section 1, Magnetic Fields and Forces
29:01, highSchool, numeric, > 1 min, wordingvariable. 133 3. Negative y direction
4. Positive y direction Part 1 of 2
A proton moves at 2.50 × 106 m/s horizontally at a right angle to a magnetic ﬁeld.
The acceleration of gravity is 9.81 m/s2 .
What is the strength of the magnetic ﬁeld
required to exactly balance the weight of the
proton and keep it moving horizontally?
Part 2 of 2
What is its direction?
1. In a horizontal plane
2. In a vertical plane
3. None of these
Holt SF 21Rev 38
29:01, highSchool, numeric, < 1 min, wordingvariable.
A proton moves at a speed of 2.0 × 107
m/s at right angles to a magnetic ﬁeld with a
magnitude of 0.10 T.
Find the magnitude of the acceleration of
the proton. 5. Negative z direction
6. Positive z direction
7. None of these
Holt SF 21Rev 40
29:01, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A proton travels with a speed of 3.0 × 106
m/s at an angle of 37◦ west of north. A
magnetic ﬁeld of 0.30 T points to the north.
Find the magnitude of the magnetic force
on the proton. (The magnetic force experienced by the proton in the magnetic ﬁeld is
proportional to the component of the proton’s
velocity that is perpendicular to the magnetic
ﬁeld.)
Part 2 of 3
What is its direction?
1. North Holt SF 21Rev 39
29:01, highSchool, numeric, < 1 min, wordingvariable. 2. South Part 1 of 2
A proton moves perpendicularly to a uniform magnetic ﬁeld, B, with a speed of
1.0 × 107 m/s and experiences an acceleration
of 2.0 × 1013 m/s2 in the positive x direction
when its velocity is in the positive z direction.
Find the magnitude of the ﬁeld. 4. East Part 2 of 2
What is its direction?
1. Negative x direction
2. Positive x direction 3. West 5. out of the Earth
6. into the Earth
7. None of these
Part 3 of 3
Find the magnitude of the proton’s acceleration as it moves through the magnetic ﬁeld. Chapter 29, section 2, Magnetism from Electric Currents 134 Conceptual 17 Q01
29:02, highSchool, multiple choice, < 1 min,
ﬁxed. Conceptual 17 Q19
29:02, highSchool, multiple choice, > 1 min,
ﬁxed. The ﬁgure represents two long, straight,
parallel wires extending in a direction perpendicular to the page. The current in the
left wire runs into the page and the current in
the right runs out of the page. Part 1 of 3
A long straight wire is aligned northsouth
and carries current in the northerly direction.
What is the direction of the magnetic ﬁeld
created directly above the wire? a b c 1. east
2. west What is the direction of the magnetic ﬁeld
created by these wires at location a, b and c?
(b is midway between the wires.)
1. up, up, down
2. up, down, up
3. down, down, up
4. down, zero, up
5. up, zero, down
6. down, up, down
Conceptual 17 Q12
29:02, highSchool, multiple choice, < 1 min,
ﬁxed.
A current is ﬂowing clockwise around a loop
placed on your desk.
What would be the direction of the resulting magnetic ﬁeld inside the loop?
1. downward
2. upward
3. clockwise
4. counterclockwise
5. no magnetic ﬁeld was generated. 3. south
4. north
5. upward
6. downward
Part 2 of 3
What is the direction of the magnetic ﬁeld
created immediately to the left of the wire?
1. east
2. west
3. south
4. north
5. upward
6. downward
Part 3 of 3
If a proton is traveling north directly above
the wire, what is the direction of the magnetic
force on the proton due to the wire?
1. east
2. west
3. south Chapter 29, section 2, Magnetism from Electric Currents
4. north
5. upward
6. downward 135 Chapter 29, section 3, Magnetic Force on a CurrentCarrying Conductor 136 Drummond HW2 01
29:03, highSchool, numeric, > 1 min, normal.
A wire carrying a current 30 A has a length
0.12 m between the pole faces of a magnet at
an angle 60 ◦ (see the ﬁgure). The magnetic
ﬁeld is approximately uniform at 0.9 T. We
ignore the ﬁeld beyond the pole pieces.
I I I B
a b
F B
θ What is the force on the wire?
Drummond HW2 02
29:03, highSchool, numeric, > 1 min, normal.
A rectangular loop of wire hangs vertically
as shown in the ﬁgure. A magnetic ﬁeld is directed horizontally, perpendicular to the wire,
and points out of the page at all points as represented by the symbol . The magnetic
ﬁeld is very nearly uniform along the horizontal portion of the wire ab (length is 0.1 m)
which is near the center of a large magnet
producing the ﬁeld. The top portion of the
wire loop is free of the ﬁeld. The loop hangs
from a balance which measures a downward
force (in addition to the gravitational force) of
3.48 × 10−2 N when the wire carries a current
0.245 A. What is the magnitude of the magnet ﬁeld
B at the center of the magnet?
Drummond HW2 05
29:03, highSchool, numeric, > 1 min, normal.
The two wires of length 2 m are 3 mm apart
and carry a current of 8 A dc.
Calculate the force between these wires.
Holt SF 21B 01
29:03, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A 6.0 m wire carries a current of 7.0 A
toward the +x direction. A magnetic force of
7.0 × 10−6 N acts on wire in the −y direction.
a) Find the magnitude of the magnetic ﬁeld
producing the force.
Part 2 of 2
b) What is its direction?
1. +x direction
2. −x direction
3. +y direction
4. −y direction
3. +z direction
4. −z direction Chapter 29, section 3, Magnetic Force on a CurrentCarrying Conductor
5. None of these
Holt SF 21B 02
29:03, highSchool, numeric, < 1 min, wordingvariable.
A wire 1.0 m long experiences a magnetic
force of 0.50 N due to a perpendicular uniform
magnetic ﬁeld.
If the wire carries a current of 10.0 A, what
is the magnitude of the magnetic ﬁeld?
Holt SF 21B 03
29:03, highSchool, numeric, < 1 min, wordingvariable.
The magnetic force on a straight 0.15 m
segment of wire carrying a current of 4.5 A is
1.0 N.
What is the magnitude of the component
of the magnetic ﬁeld that is perpendicular to
the wire?
Holt SF 21B 04
29:03, highSchool, numeric, < 1 min, wordingvariable.
The magnetic force acting on a wire that
is perpendicular to a 1.5 T uniform magnetic
ﬁeld is 4.4 N.
If the current in the wire is 5.0 A, what
is the length of the wire that is inside the
magnetic ﬁeld?
Holt SF 21Rev 32
29:03, highSchool, numeric, < 1 min, wordingvariable.
A wire carries a 10.0 A current at an angle
90.0◦ from the direction of a magnetic ﬁeld
If the magnitude of the magnetic force on
a 5.00 m length of the wire is 15.0 N, what is
the strength of the magnetic Field?
Holt SF 21Rev 33
29:03, highSchool, numeric, < 1 min, wordingvariable. 137 A thin 1.00 m long copper rod in a uniform
magnetic ﬁeld has a mass of 50.0 g. When the
rod carries a current of 0.245 A, it ﬂoats in
the magnetic ﬁeld.
The acceleration of gravity is 9.81 m/s2 .
What is the ﬁeld strength of the magnetic
ﬁeld?
Holt SF 21Rev 41
29:03, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
In the ﬁgure, a 15 cm length of conducting
wire that is free to move is held in place
between two thin conducting wires. All of the
wires are in a magnetic ﬁeld. When a 5.0 A
current is in the wire, as shown in the ﬁgure,
the wire segment moves upward at a constant
velocity.
The acceleration of gravity is 9.81 m/s2 .
15 cm 5A 5A 5A a) Assuming the wire slides without friction
on the two vertical conductors and has a mass
of 0.15 kg, ﬁnd the magnitude of the minimum
magnetic ﬁeld that is required to move the
wire.
Part 2 of 2
b) What is its direction?
1. Out of the page
2. Into the page
3. Toward the left edge of the page
4. Toward the right edge of the page
5. Toward the top edge of the page
6. Toward the bottom edge of the page Chapter 29, section 3, Magnetic Force on a CurrentCarrying Conductor
7. None of these
Holt SF 21Rev 42
29:03, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A 15 A current is directed along the positive xaxis and perpendicular to a uniform
magnetic ﬁeld. The conductor experiences a
magnetic force per unit length of 0.12 N/m in
the negative y direction.
Calculate the magnitude of the magnetic
ﬁeld in the region through which the current
passes.
Part 2 of 2
What is its direction?
1. positive x direction
2. negative x direction
3. positive y direction
4. negative y direction
5. positive z direction
6. negative z direction
7. None of these
Sliding
29:03, highSchool, numeric, > 1 min, normal.
A metal wire of mass 50 kg slides without friction on two horizontal rails spaced a
distance of 50 m apart. The track lies in a
vertical uniform magnetic ﬁeld of 50 T. A
constant current 50 A from a generator ﬂows
down one rail, across the wire, down the other
rail back to the generator.
Find the velocity of the wire at t = 50 s,
assuming it to be at rest at t = 0. 138 Chapter 29, section 5, Motion of a Charged Particle in a Magnetic Field
Circular Motion mid2
29:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Consider the circular motion of a positively
charged particle in the plane of this paper, due
to a constant magnetic ﬁeld B which points
out of the paper. Neglect the eﬀects due to
gravity.
B B
What is the direction of the orbital motion
of the particle?
1. counterclockwise
2. clockwise
3. Unable to determine
Part 2 of 2
What is the radius of the orbit?
1. r =
2. r =
3. r =
4. r =
5. r =
6. r =
7. r =
8. r = qv
mB
qB
mv
mB
qv
mv
qB
qm
vB
vB
qm
m v2
qB
qB
m v2 139 q v2
mB
v2 B
10. r =
qm
9. r = Holt SF 21Rev 43
29:05, highSchool, numeric, < 1 min, wordingvariable.
A proton moves in a circular path perpendicular to a constant magnetic ﬁeld so that it
takes 1.00 × 10−6 s to complete the revolution.
Determine the strength of the constant
magnetic ﬁeld. The angular speed is given
in radians per unit time.
Holt SF 21Rev 44
29:05, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A single charged positive ion that has a
mass of 6.68 × 10−27 kg moves clockwise with
a speed of 1.00 × 104 m/s. The positively
charged ion moves in a circular path that has
a radius of 3.00 cm.
Find the strength of the uniform magnetic
ﬁeld.
Part 2 of 2
What is its direction?
1. toward the observer
2. away from the observer
3. to the observer’s left
4. to the observer’s right
5. None of these
Holt SF 21Rev 45
29:05, highSchool, numeric, < 1 min, wordingvariable.
Assume that Earth’s magnetic ﬁeld is everywhere perpendicular to the path of a proton and that Earth’s magnetic ﬁeld has an Chapter 29, section 5, Motion of a Charged Particle in a Magnetic Field
intensity of 4.00 × 10−8 T.
What speed would a proton need to achieve
in order to circle Earth 1000.0 km above the
magnetic equator?
Holt SF 21Rev 46
29:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An electron moves in a circular path perpendicular to a magnetic ﬁeld that has a magnitude of 1.00 × 10−3 T. The angular momentum of the electron as it moves around the
center of the circle is 4.00 × 10−25 J·s.
Find the radius of the circular path.
Part 2 of 2
Find the speed of the electron. 140 Chapter 29, section 10, Cyclotrons and Synchrotrons
Hewitt CP9 24 E31
29:10, highSchool, multiple choice, < 1 min,
ﬁxed.
A beam of highenergy protons emerges
from a cyclotron.
Is there a magnetic ﬁeld associated with
these particles? Why or why not?
1. There is a magnetic ﬁeld associated with
these protons because they are positively
charged and in motion.
2. There is no magnetic ﬁeld associated with
these protons because there is an electric ﬁeld
around them.
3. There is a magnetic ﬁeld associated with
these protons because they have very high
energy.
4. There is no magnetic ﬁeld associated
with these protons because they have a positive charge. 141 Chapter 29, section 11, Mass Spectrometer
Hewitt CP9 24 E36
29:11, highSchool, multiple choice, < 1 min,
ﬁxed.
In a mass spectrometer, ions are directed
into a magnetic ﬁeld, where they curve around
a magnetic ﬁeld line and strike a detector.
If a variety of singly ionized atoms travel
at the same speed through the magnetic ﬁeld,
what kind of deﬂection would you expect?
1. All of them should be deﬂected by the
same amount.
2. The ions with smaller masses will be bent
more.
3. The ions with smaller masses will be bent
less.
4. It cannot be predicted. 142 Chapter 30, section 2, Magnetic Field Due to a Straight Wire
Current Induced by Wire
30:02, highSchool, multiple choice, > 1 min,
wordingvariable. wire Consider a long straight wire and a wire
loop in the same plane. The long wire has a
current ﬂowing in the direction shown. The
wire loop is moving in the direction shown. straight I v
wire loop The current in the loop is ﬂowing
1. clockwise.
2. counterclockwise.
3. There is no current in the loop.
Drummond HW2 03
30:02, highSchool, numeric, > 1 min, normal.
A vertical electric wire in the wall of a
building carries a DC current of 25 A upward. x
I
S E
(out) N What is the magnitude of the magnet ﬁeld
at a point 0.1 m due north of this wire? 143 Chapter 30, section 3, Magnetic Force Between Two Parallel Conductors
Hewitt CP9 24 E40
30:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Will a pair of parallel currentcarrying wires
exert forces on each other? 2.
3.
4. 1. No; the magnetic ﬁeld generated by the
currents of the wires does not aﬀect the wires
themselves. 5. 2. No; the two wires attract each other by
the magnetic ﬁeld generated by their currents
and repel each other due to the like charges
of the moving particles in the wires. The two
forces are equal in magnitude. 7. 6. 8.
9. 3. Yes; the magnetic ﬁeld generated by the
current in one wire is perpendicular to the
current in the other wire and vise versa.
4. Yes; the wires are electrically charged.
5. No; no net magnetic ﬁeld is generated.
Wires with diﬀerent currents
30:03, highSchool, multiple choice, > 1 min,
ﬁxed.
Consider two parallel wires where the magnitude of the left current is 2 I0 and that
of the right current is I0 . Point A is midway between the wires, and B is an equal
distance on the other side of the wires. A B The ratio of the magnitude of the magnetic
ﬁeld at point A to that at point B is
1. 5
BA
=
BB
2 10. BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB
BA
BB =2
=4
=3
=9
4
3
2
=
3
1
=
2
1
=
3
= =0 144 Chapter 30, section 4, Ampere’s Law
Crossed Wires
30:04, highSchool, multiple choice, > 1 min,
ﬁxed.
A long straight wire 1 lies along the xaxis.
A long straight wire 2 lies along the y axis so
as to pass very near, but not quite touch wire
1 at the origin.
If both wires are free to move, what happens when currents are sent simultaneously in
the +x direction through wire 1 and in the +y
direction through wire 2? [Note: “clockwise
around origin” refers to an observer looking
down on an xy plane in which +x is to the
right and +y upward].
1. Neither wire moves.
2. 1 accelerates in the +y direction, 2 in the
+x direction.
3. 1 accelerates in the −y direction, 2 in the
+x direction.
4. 1 accelerates in the −y direction, 2 in the
x direction.
5. 1 accelerates in the +y direction, 2 in the
x direction.
6. 1 rotates counterclockwise, 2 clockwise
around the origin.
7. 1 rotates clockwise, 2 counterclockwise
around the origin.
8. Both wires rotate counterclockwise
around the origin.
9. Both wires rotate clockwise around the
origin.
10. Both wires accelerate along the direction
of current ﬂow. 145 Chapter 30, section 5, The Magnetic Field of Current Loops
Conceptual 17 Q03
30:05, highSchool, multiple choice, < 1 min,
ﬁxed.
An electric current runs through a coil of
wire as shown. A permanent magnet is located to the right of the coil. The magnet is
free to rotate.
N
i i S Pivot What will happen to the magnet if its original orientation is as shown in the ﬁgure?
1. rotate clockwise
2. rotate counterclockwise
3. remain still
4. Unable to determine
Hewitt CP9 25 E02
30:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does an iron core increase the magnetic induction of a coil?
1. An iron core can increase the current in
the coil.
2. The magnetic domains that become
aligned in the iron core contribute to increase
the overall magnetic ﬁeld of the coil.
3. An iron core can generate an electromagnetic wave to change the magnetic ﬁeld in a
coil.
4. An iron core is a magnet and generates a
magnetic ﬁeld with or without a coil. 146 Chapter 30, section 9, Gauss’s Law in Magnetism
Gauss Law Magnetism
30:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Gauss’ law for magnetism tells us
1. the net charge in any given volume.
2. that the line integral of a magnetic ﬁeld
around any closed loop vanishes.
3. the magnetic ﬁeld of a current element.
4. that the magnetic monopoles do not exist.
5. that charges must be moving to produce
magnetic ﬁelds. 147 Chapter 30, section 12, Magnetism in Matter 148 3. No diﬀerence
Conceptual 17 Q08
30:12, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the underlying basis of the magnetic ﬁeld in a magnetized piece of iron? Two Magnetic Moments
30:12, highSchool, multiple choice, < 1 min,
ﬁxed.
Given: A loop with current I produces a
magnetic moment µ , as shown below. 1. The motion of electrons constitues an
electric current which produces a magnetic
ﬁeld. µ 2. The charge in the atom produces a magnetic ﬁeld.
3. The magnetic monopole in the atom creates the magnetic ﬁeld.
Conceptual 24 Q08
30:12, highSchool, multiple choice, < 1 min,
ﬁxed.
A normal piece of iron produces no external magnetic ﬁeld. Suppose a piece of iron
consisted of one very large domain instead of
many small ferromagnetic domains.
Would this piece of iron produce an external
magnetic ﬁeld?
1. No. It does not create magnetic ﬁeld
because the net magnetic ﬁeld is zero.
2. No. It does not create magnetic ﬁeld at
all.
3. Yes. It creates magnetic ﬁeld.
Conceptual 24 Q13
30:12, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the diﬀerence of one material having larger Curie constant than another (when
placed in an applied magnetic ﬁeld)? Consider the following four conﬁgurations
of two loops each, A, B , C , and D. The
placement and current directions of the loops
are shown below. The loops are characterized
by their magnetic moments µ.
µ µ A B
µ Cµ µ µ µ µD For conﬁgurations A and B , assume that
the two current loops have the same axis and
move freely along the axis. For conﬁgurations
C and D, assume that the two current loops
are on in same plane and move freely only in
that plane.
In which case(s) are the current loops attracted to oneanother?
1. A, C
2. A 1. Produces stronger extra magnetic ﬁeld. 3. B 2. Produces weaker extra magnetic ﬁeld. 4. C Chapter 30, section 12, Magnetism in Matter
5. D
6. A, D
7. B , C
8. B , D
9. None of these. 149 Chapter 30, section 13, Diamagnetism
Conceptual 24 Q07
30:13, highSchool, multiple choice, < 1 min,
ﬁxed.
Compare the way that the motion of electrons in a diamagnetic material creates an
opposing magnetic ﬁeld with the way electrons in a copper wire accomplish the same
end.
1. They have the same motion.
2. Diamagnetic material creates a magnetic
ﬁeld making the motion of electrons faster.
3. Magnetic ﬁeld created by the copper wire
makes the motion of electrons faster. 150 Chapter 30, section 14, Paramagnetism 151 rection.
Conceptual 24 Q09
30:14, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 2
A paramagnetic material will acquire a
magnetization if it is placed in an applied
magnetic ﬁeld.
What happens to the magnetization of a
paramagnetic material if the temperature of
the material is quadrupled?
1. decrease by a factor of 4
2. decrease by a factor of 2
3. decrease by a factor of 3
5. increase by a factor of 4
6. No change
Part 2 of 2
What happens to the magnetization of a paramagnetic material if the temperature of the
material and the applied magnetic ﬁeld is simultaneously quadrupled?
1. decrease by a factor of 4
2. decrease by a factor of 2
3. decrease by a factor of 3
5. increase by a factor of 4
6. No change
Paramagnet
30:14, highSchool, multiple choice, < 1 min,
ﬁxed.
A magnetic ﬁeld B0 is applied to a paramagnet at room temperature.
In the interior, the ﬁeld produced by the
magnetic dipoles of this substance is
1. greater than B0 and in the opposite di 2. less than B0 and in the opposite direction.
3. greater than B0 and in the same direction.
4. less than B0 and in the same direction.
5. the same as B0 . Chapter 31, section 1, Faraday’s Law of Induction
Brightest Light Bulb
31:01, highSchool, multiple choice, > 1 min,
wordingvariable.
A conducting loop (octagonal) around a
magnetic ﬁeld (circular) contains three lightbulbs (labeled A, B , and C ). The wires
connecting the bulbs are ideal, with no resistance. The loop is ground at one point as
shown in the ﬁgure below.
The magnetic ﬁeld is increasing rapidly.
B B B B B A C Initial Case: The circuit consists of two
identical light bulbs of equal resistance, R,
connected in series, leading to a loop equation
E − 2 i R = 0.
i
Figure 1: B B X Y
B B i
Primed Case: Now connect the points
C and D with a wire CAD, (see the ﬁgure
below).
i3
Figure 2:
D i1 Rank order the brightness of the three
bulbs, from brightest to least bright.
1. None of these. 152 B A B X Y
B i2 B 2. A > B > C
3. A > C > B
4. A > B = C
5. A = C > B
6. B > C > A
Circuit Around a Solenoid 04
31:01, highSchool, multiple choice, > 1 min,
ﬁxed.
A solenoid with circular cross section produces a steadily increasing magnetic ﬂux
through its cross section. There is an octagonally shaped circuit surrounding the solenoid
as shown below.
The increasing magnetic ﬂux gives rise to a
counterclockwise induced emf E . i3 C What happens after the points C and D are
connected by a wire as in the second (primed)
case?
1. Bulb Y goes out and bulb X gets
brighter.
2. Bulb X goes out and bulb Y gets
brighter.
3. Bulb Y goes out and bulb X remains at
the same brightness.
4. Bulb X goes out and bulb Y remains at
the same brightness.
5. Bulb Y goes out and bulb X gets dim Chapter 31, section 1, Faraday’s Law of Induction 153 mer.
6. Bulb X goes out and bulb Y gets dimmer.
Conceptual 17 Q17
31:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Assume you wrap a wire around Earth’s
equator at an altitude of 200 kilometers and
run an electric current through it in the westerly direction.
What eﬀect would this have on the Earth’s
natural magnetic ﬁeld at the Earth’s surface?
1. reinforcing the ﬁeld
2. canceling the ﬁeld
3. no eﬀect
4. Unable to determine
Faraday Equation
31:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose you are looking into the end of
a long cylindrical tube in which there is a
uniform magnetic ﬁeld pointing away from
you.
What is the direction of the induced electric
ﬁeld if the magnitude of the magnetic ﬁeld is
decreased with time?
1. clockwise
2. counterclockwise
3. toward you
4. away from you
5. radially outward from the axis of the
tube
6. radially inward toward the axis of the
tube Hewitt CP9 25 R01
31:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Exactly what was it that Michael Faraday
and Joseph Henry discovered?
1. The force acting on an electron in a magnetic ﬁeld is perpendicular to its velocity.
2. A wire of constant current can produce a
magnetic ﬁeld.
3. Voltaic cells
4. Electric current can be produced in a
wire simply by moving a magnet in or out of
a coiled part of the wire.
Holt SF 22A 02
31:01, highSchool, numeric, > 1 min, wordingvariable.
A coil with 205 turns of wire, a total resistance of 23 Ω, and a crosssectional area of
0.25 m2 is positioned with its plane perpendicular to the ﬁeld of a powerful electromagnet.
What average current is induced in the coil
during the 0.25 s that the magnetic ﬁeld drops
from 1.6 T to 0.0 T?
Holt SF 22A 03
31:01, highSchool, numeric, > 1 min, wordingvariable.
A circular wire loop with a radius of 0.33 m
is located in an external magnetic ﬁeld of
strength +0.35 T that is perpendicular to the
plane of the loop. The ﬁeld strength changes
to −0.25 T in 1.5 s. (The plus and minus
signs for a magnetic ﬁeld refer to opposite
directions through the coil.)
Find the magnitude of the average induced
emf during this interval.
Holt SF 22Rev 11
31:01, highSchool, numeric, > 1 min, wordingvariable. Chapter 31, section 1, Faraday’s Law of Induction
A rectangular coil 0.055 m by 0.085 m is
positioned so that its crosssectional area is
perpendicular to the direction of a magnetic
ﬁeld. The coil has 75 and a total resistance of
8.7 Ω and the ﬁeld decreases at a rate of 3.0
T/s.
What is the magnitude of the induced current in the coil?
Holt SF 22Rev 42
31:01, highSchool, numeric, > 1 min, wordingvariable.
A bolt of lightning, such as the one shown
on the left in the ﬁgure below, behaves like a
vertical wire conducting electric current. As
a result, it produces a magnetic ﬁeld whose
strength varies with the distance from the
lightning. A 105turn circular coil is oriented
perpendicular to the magnetic ﬁeld, as shown
in the ﬁgure. 0.833 m The coil has a radius of 0.833 m. The
magnetic ﬁeld at the coil drops from 4.72
×10−3 T to 0.00 T in 10.5 µs.
What is the average emf induced in the
coil? 154 Chapter 31, section 2, Motional EMF 155 Conceptual 17 03
31:02, highSchool, numeric, > 1 min, normal. 2. The motor would rotate with an constant
speed even if you stop turning it. Part 1 of 3
In the laboratory, you have arranged to
have a magnetic ﬁeld that points north
with a strength of 0.5 T and an electric
ﬁeld that points downward with a strength
6 × 106 N/C. An electric charge with a magnitude 9 × 10−9 C passes through the laboratory. The force on the charge due to the
electric ﬁeld is given by F = q E . The force
on the charge due to the magnetic ﬁeld is
given by F = q v B , where v is the speed of
the particle. The direction of the magnetic
force is given by the righthand rule. Neglect
the gravitational force.
What direction would the charge have to
travel in order for it to pass through the room
undeﬂected? 3. There would be no current in the wires. 1. east
2. west
3. north
4. south
5. downward
6. upward
Part 2 of 3
What is the strength of the electric force?
Part 3 of 3
How fast would it have to travel so that it
passes through the room undeﬂected?
Conceptual 17 Q07
31:02, highSchool, multiple choice, < 1 min,
ﬁxed.
If you took an electric motor and turned it
by hand, what would happen then?
1. Current would ﬂow in the wires. Chapter 31, section 3, Lenz’s Law
Conceptual 17 Q15
31:03, highSchool, multiple choice, < 1 min,
ﬁxed.
A bar magnet is dropped, north pole down,
so that it falls through a circular piece of wire,
as shown.
S
N What is the direction of the induced current
in the loop before it passes through the wire
(viewed from top)? After it passes through? 156 3. The magnet will slow down because the
changing magnetic ﬁeld will induce current in
the loop, which will interact with the magnet
and repel it.
4. None of these
Light Bulb and Solenoid 01
31:03, highSchool, multiple choice, > 1 min,
ﬁxed.
A light bulb and a solenoid are connected
in series to a battery. An irod rod is thrust
rapidly into the solenoid and later rapidly
removed.
The bulb
1. Brightens in, Brightens out
2. Dims in, Dims out 1. clockwise; counterclockwise 3. No change in or out 2. clockwise; clockwise 4. No change in, Dims out 2. counterclockwise; clockwise 5. No change in, Brightens out 2. counterclockwise; counterclockwise 6. Dims in, No change out 3. no induced current 7. Brightens in, No change out 4. Unable to determine 8. Brightens in, Dims out Hewitt CP9 25 E31
31:03, highSchool, multiple choice, < 1 min,
ﬁxed.
If a bar magnet is thrown into a coil of
highresistance wire, what will happen?
1. The magnet will change its polarity because the electromagnetic waves produced by
the magnet and the coil will interact with each
other.
2. The magnet will slow down and get hotter
because the kinetic energy of the magnet will
transfer to heat. 9. Dims in, Brightens out
10. Remains brighter the entire time
Solenoid and a Ring
31:03, highSchool, multiple choice, > 1 min,
ﬁxed.
The switch S has been closed for a long time
and a constant current is ﬂowing through a
solenoid, creating a magnetic ﬁeld. Chapter 31, section 3, Lenz’s Law iron core S
The force which the magnetic ﬁeld exerts
on a conducting ring positioned as shown is
1. upward.
2. downward.
3. to the right.
4. to the left.
5. There is neither a force nor a torque.
6. There is no force, only a torque. 157 Chapter 31, section 4, Induced EMF in a Moving Conductor
Conceptual 17 Q05
31:04, highSchool, multiple choice, < 1 min,
ﬁxed. 158 4. No; the amount of magnetic ﬁeld penetrating the loop does not change as it rotates.
5. Unable to determine Part 1 of 2
Suppose you are in a location where the
magnetic ﬁeld of Earth points north and is
horizontal to the ground. A circular wire is
rotated as shown in the ﬁgure (the axis of
rotation is along the northsouth direction). N
W
B B E Conceptual 17 Q13
31:04, highSchool, multiple choice, < 1 min,
ﬁxed.
A rectangular piece of wire is moving to the
right as shown. It passes through a region
where there is a magnetic ﬁeld pointing into
the page, (magnetic ﬁeld indicated by the
shaded region). S wire
v Will there be an induced current in the
wire?
1. Yes; current direction doesn’t change.
2. Yes; current direction reverses every cycle.
3. Yes; the amount of magnetic ﬁeld penetrating the loop changes as it rotates. When the loop of wire is in the position
shown in the ﬁgure, is there an induced current in the loop?
1. Yes; the current runs clockwise.
2. Yes; the current runs counterclockwise 4. No; the amount of magnetic ﬁeld penetrating the loop does not change as it rotates. 3. No
4. Unable to determine 5. Unable to determine
Part 2 of 2
What if the axis of rotation were in the eastwest direction?
1. Yes; current direction doesn’t change.
2. Yes; current direction reverses every cycle.
3. Yes; the amount of magnetic ﬁeld penetrating the loop changes as it rotates. Conceptual 17 Q16
31:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
A square loop of copper wire is moving to
the right in a uniform, downwardpointing
magnetic ﬁeld, as shown. Chapter 31, section 4, Induced EMF in a Moving Conductor
wire loop
B
v What is the direction of the force on an
electron moving to the right in this magnetic
ﬁeld? 159 31:04, highSchool, numeric, > 1 min, wordingvariable.
A single circular loop with a radius of 22 cm
is placed in a uniform external magnetic ﬁeld
with a strength of 0.50 T so that the plane of
the coil is perpendicular to the ﬁeld. The coil
is pulled steadily out of the ﬁeld in 0.25 s.
Find the average induced emf during this
interval.
Holt SF 22A 04
31:04, highSchool, numeric, > 1 min, wordingvariable. 1. right
2. left
3. upward
4. downward
Part 2 of 2
Is there an induced current in this square
current loop?
1. Yes; the direction is clockwise.
2. Yes; the direction is counterclockwise.
3. No
4. Unable to determine
Hewitt CP9 26 R02
31:04, highSchool, multiple choice, < 1 min,
ﬁxed.
What does a changing electric ﬁeld induce?
1. charges
2. magnetic ﬁeld
3. light
4. electrons
5. Nothing
Holt SF 22A 01 A 505turn circularloop coil with a diameter of 15.5 cm is initially aligned so that its
plane is perpendicular to the Earth’s magnetic ﬁeld. In 2.77 ms the coil is rotated 90.0◦
so that its plane is parallel to the Earth’s
magnetic ﬁeld. An average emf of 0.166 V is
induced in the coil.
What is the value of the Earth’s magnetic
ﬁeld?
Holt SF 22B 02
31:04, highSchool, numeric, < 1 min, wordingvariable.
A circular coil with a radius of 0.22 m and
17 turns is rotated in a uniform magnetic ﬁeld
of 1.7 T. The coil rotates with a constant
frequency of 2.0 Hz.
Determine the maximum value of the emf
induced in the coil.
Holt SF 22B 03
31:04, highSchool, numeric, < 1 min, wordingvariable.
A square coil with an area of 0.045 m2
consists of 120 of wire. The coil rotates about
a vertical axis at 157 rad/s. The horizontal
component of the Earth’s magnetic ﬁeld at
the location of the loop is 2.0 × 10−5 T.
Calculate the maximum emf induced in the
coil.
Holt SF 22Rev 10 Chapter 31, section 4, Induced EMF in a Moving Conductor
31:04, highSchool, numeric, > 1 min, wordingvariable.
A ﬂexible loop of conducting wire has a
radius of 0.12 m and is perpendicular to a
uniform magnetic ﬁeld with a strength of 0.15
T, as shown in the ﬁgure. 160 the poles of a horseshoe magnet with a magnetic ﬁeld of 2.5 ×10−2 T. The area of the
loop is 7.54 ×10−3 m2 and is moved perpendicular to the magnetic ﬁeld lines.
In what time interval will the student have
to move the loop out of the magnetic ﬁeld in
order to induce an emf of 1.5 V?
Holt SF 22Rev 38
31:04, highSchool, numeric, > 1 min, wordingvariable. The loop is grasped at opposite ends and
stretched until it closes to an area of 3 ×10−3
m2 , as shown in the ﬁgure. It takes 0.20 s to close the loop.
Find the magnitude of the average emf induced in the loop during this time.
Holt SF 22Rev 12
31:04, highSchool, numeric, > 1 min, wordingvariable.
A 52turn coil with an area of 5.5 ×10−3 m2
is dropped from a position where B = 0.0 T
to a new position where B = 0.55 T. The
displacement occurs in 0.25 s and the area of
the coil is perpendicular to the magnetic ﬁeld
lines.
What is the resulting average emf induced
in the coil?
Holt SF 22Rev 37
31:04, highSchool, numeric, < 1 min, wordingvariable.
A student attempts to make a simple generator by passing a single loop of wire between A student attempts to make a simple generator by wrapping a long piece of wire across
a cylinder with a crosssectional area of 1.886
×10−3 m2 . She then passes the coil between
the poles of a horseshoe magnet with a magnetic ﬁeld of 2.5 ×10−2 T. The student ﬁnds
that by removing the coil perpendicular to the
magnetic ﬁeld lines during 0.25 s, an emf of
149 mV can be induced.
How many turns of wire are wrapped
around the coil?
Holt SF 22Rev 39
31:04, highSchool, numeric, > 1 min, wordingvariable.
A coil of 325 and an area of 19.5 ×10−4 m2
is removed from a uniform magnetic ﬁeld at
an angle of 45◦ in 1.25 s. The induced emf is
15 mV.
What is the magnetic ﬁeld strength?
Rectangular Loop 02
31:04, highSchool, multiple choice, > 1 min,
wordingvariable.
A rectangular loop of wire is pulled through
a magnetic ﬁeld B (into the page). Shown
below are four diﬀerent stages of development
of this procedure, labeled A, B , C , and D.
The rectangular loop has a constant speed
as it is pulled through the loop. Chapter 31, section 4, Induced EMF in a Moving Conductor B 4. FB = FC > FA = FD B 5. FB > FD = FA > FC v FA 6. FA > FD = FB > FC
B B 7. FA > FC = FB > FD
8. FB > FC = FA > FD B B 9. FA > FC > FB > FD
v FB
B 10. FB > FC > FA > FD B B B
v FC
B B B B FD B B v Figure: The force vector is not
to scale. The velocity vector is
to scale; (i.e., constant speed).
Select the correct rank ordering of the magnitudes of the force pulling the rectangular
loop (at constant speed) in the four stages
shown above.
1. FB = FD > FA = FC
2. FA = FD > FB = FC
3. FA = FC > FB = FD 161 Chapter 31, section 5, Induced Electric Fields
Conceptual 17 Q04
31:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose you have a Frisbee with a copper wire glued around its outer circumference. When you throw the Frisbee correctly,
it maintains a constant orientation with the
ground. When you throw it incorrectly, it
wobbles.
In which of case will a current be induced
in the copper wire due to Earth’s magnetic
ﬁeld?
1. correct throw
2. incorrect throw
3. Either
4. Neither
Hewitt CP9 24 E07
31:05, highSchool, multiple choice, < 1 min,
ﬁxed.
What surrounds a stationary electric
charge? What surrounds a moving electric
charge? (Ignore the gravitational ﬁeld.)
1. electric ﬁelds for both
2. magnetic ﬁelds for both
3. electric ﬁeld; magnetic ﬁeld
4. magnetic ﬁeld; electric ﬁeld
5. electric ﬁeld; electric and magnetic ﬁelds
6. It cannot be predicted.
Hewitt CP9 25 E40
31:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Would electromagnetic waves exist if
changing magnetic ﬁelds could produce elec 162 tric ﬁelds, but changing electric ﬁelds could
not in turn produce magnetic ﬁelds?
1. Yes; only the magnetic ﬁeld changes in
electromagnetic waves.
2. Yes; as long as we have a magnet, there is
a magnetic ﬁeld to form the electromagnetic
waves.
3. No; electric and magnetic ﬁelds coexist in
electromagnetic waves by ﬁeld induction.
4. Yes; electromagnetic waves consist of either electric or magnetic ﬁelds, but not necessary both.
5. Can’t be determined unless we know the
propagation medium of the electromagnetic
waves.
6. More information is needed. Chapter 31, section 6, Electric Field from a Changing Magnetic Flux
Hewitt CP9 26 R01
31:06, highSchool, multiple choice, < 1 min,
ﬁxed.
What does a changing magnetic ﬁeld induce?
1. charges
2. electric ﬁeld
3. light
4. electrons
5. Nothing
Light Bulb and Solenoid 02
31:06, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Consider the set up shown in the ﬁgure
where a solenoid has a steadily increasing
magnetic ﬂux which generates identical induced emf’s for the two cases illustrated.
i
(1) #2 #1
A B Case 1: Two identical light bulbs are in
series. The corresponding electrical power
consumed by bulb 1 and bulb 2 are P1 and P2 ,
respectively.
C
(2) D #2 #1
A B
F Case 2: Bulb 2 is shorted by a wire which
is connected between the two points C and
F . The corresponding electrical power consumed by bulb 1 and bulb 2 are P1 and P2 ,
respectively.
Hint: It may be helpful to ﬁrst write down 163 the loop equation for ACDF A and ACBF A.
P
The ratio of 1 is given by
P1
P
1. 1 = 4 .
P1
P
2. 1 = 8 .
P1
P
3. 1 = 3 .
P1
P
4. 1 = 2 .
P1
P
5. 1 = 1 .
P1
P
6. 1 = 0 .
P1
P
1
7. 1 = .
P1
2
1
P
8. 1 = .
P1
3
P
1
9. 1 = .
P1
4
P
1
10. 1 = .
P1
8
Part 2 of 2
Consider the set up shown in the ﬁgure where
a solenoid has a steadily increasing magnetic
ﬂux which generates identical induced emf’s
for the two cases illustrated.
i
(1) #2 #1
B A Case 1: Two identical light bulbs are in
series. The corresponding electrical power
consumed by bulb 1 and bulb 2 are P1 and P2 ,
respectively. Chapter 31, section 6, Electric Field from a Changing Magnetic Flux
C (3) o #2 #1
A B i2 D i1 Case 2: Let the points C and D be on the
symmetry line of the diagram. Connect points
C and D by a wire, which equally divides the
magnetic ﬂux. The corresponding electrical
power consumed by bulb 1 and bulb 2 are P1
and P2 , respectively.
Hint: It may be helpful to ﬁrst write down
the loop equation for ACODA.
P
The ratio of 1 is given by
P1
P
1. 1 = 1 .
P1
P
2. 1 = 8 .
P1
P
3. 1 = 3 .
P1
P
4. 1 = 2 .
P1
P
5. 1 = 4 .
P1
P
6. 1 = 0 .
P1
1
P
7. 1 = .
P1
2
P
1
8. 1 = .
P1
3
P
1
9. 1 = .
P1
4
1
P
10. 1 = .
P1
8 164 Chapter 31, section 7, Generators and Motors 165 Hewitt CP9 25 E11
31:07, highSchool, multiple choice, < 1 min,
ﬁxed. Holt SF 22B 01
31:07, highSchool, numeric, < 1 min, wordingvariable. What is the primary diﬀerence between an
electric motor and an electric generator?
1. An electric motor produces electricity
while an electric generator does mechanic
work with the input of electricity. In a model generator, a 510turn rectangular coil 0.082 m by 0.25 m rotates with an
angular frequency of 12.8 rad/s in a uniform
magnetic ﬁeld of 0.65 T.
What is the maximum emf induced in the
coil? 2. An electric motor is often much more
complicated in structure than electric generator. Holt SF 22B 04
31:07, highSchool, numeric, < 1 min, wordingvariable. 3. Structurally they are similar but the electric generator is more eﬃcient than the electric motor. A maximum emf of 90.4 V is induced in
a generator coil rotating with a frequency of
65 Hz. The coil has an area of 230 cm2 and
rotates in a magnetic ﬁeld of 1.2 T.
How many turns are in the coil? 4. Structurally they are similar and some devices are designed to operate either as motors
or generators.
5. Structurally they are similar but the electric motor is more eﬃcient than the electric
generator.
Hewitt CP9 25 E13
31:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Does the voltage output increase when a
generator is made to spin faster?
1. No; it will only increase the output current of the generator.
2. Yes; according to Faraday’s law of induction, the faster the change of magnetic ﬁeld in
a coil, the greater the induced voltage.
3. No; the voltage output increases only
when the magnetic ﬁeld gets stronger.
4. Yes; the faster a generator spins, the
stronger the magnetic ﬁeld it produces.
5. None of these Holt SF 22Rev 23
31:07, highSchool, numeric, < 1 min, wordingvariable.
A generator can be made using the component of Earth’s magnetic ﬁeld that is parallel to Earth’s surface. A 112turn square wire
coil with an area of 4.41 ×10−2 m2 is mounted
on a shaft so that the crosssectional area of
the coil is perpendicular to the ground. The
shaft then rotates with a frequency of 25.0
Hz. The horizontal component of the Earth’s
magnetic ﬁeld at the location of the loop is
5.00 ×10−5 T.
Calculate the maximum emf induced in the
coil by Earth’s magnetic ﬁeld.
Holt SF 22Rev 24
31:07, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
An ac generator consists of 45 turns of wire
with an area of 0.12 m2 . The loop rotates in
a magnetic ﬁeld of 0.118 T at a constant frequency of 60.0 Hz. The generator is connected
across a circuit load with a total resistance of Chapter 31, section 7, Generators and Motors
35 Ω.
a) Find the maximum emf induced by the
generator.
Part 2 of 2
b) Find the maximum induced current. 166 Chapter 31, section 9, Maxwell’s Equations
Maxwell Contribution
31:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Maxwell’s great contribution to electrodynamic theory was his idea that
1. work is required to move a magnetic pole
through a current loop.
2. a timevarying electric ﬂux acts as a current for the purposes of producing a magnetic
ﬁeld.
3. the speed of light could be determined
from simple electrostatic and magnetostatic
experiments (ﬁnding the values of µ0 and
0 ).
4. the magnetic force on moving charges is
perpendicular to both v and B .
5. magnetism could be explained in terms of
circulating currents in atoms.
6. the charge to mass ratio of the electron
was a constant. 167 Chapter 32, section 7, Oscillations in an LC Circuit
Simple lc circuit
32:07, highSchool, numeric, > 1 min, normal.
A 40 µF capacitor is connected in series
with a 10 mH inductance and a switch. The
capacitor is ﬁrst charged to a voltage of 120 V.
The charging battery is then removed, and the
switch is closed. Then the current undergoes
oscillations.
What is the maximum current in the circuit? 168 Chapter 33, section 1, AC Sources
Holt SF 22C 02
33:01, highSchool, numeric, < 1 min, wordingvariable.
The current in an AC circuit is measured
with an ammeter, which gives a reading of 5.5
A.
Calculate the maximum AC current.
Holt SF 22Rev 25
33:01, highSchool, numeric, < 1 min, normal.
The rms potential diﬀerence across highvoltage transmission lines in Great Britain is
220000 V.
What is the maximum potential diﬀerence?
Holt SF 22Rev 44
33:01, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The alternating potential diﬀerence of a
generator is represented by the equation
E = (245 V) sin(560 rad/s) t ,
where E is in volts and t is in seconds.
Find the frequency of the potential diﬀerence of the source.
Part 2 of 2
Find the maximum potential diﬀerence output of the source. 169 Chapter 33, section 3, Resistors in an AC Circuit 170 diﬀerence?
Holt SF 22C 01
33:03, highSchool, numeric, > 1 min, normal.
Part 1 of 3
An rms potential diﬀerence of 120 V is
placed across a light bulb with a resistance of
25 Ω.
What is the rms current in the light bulb?
Part 2 of 3
What is the maximum value of current?
Part 3 of 3
What is the maximum value for the potential
diﬀerence?
Holt SF 22C 03
33:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A toaster is plugged into a source of alternating potential diﬀerence with an rms value
of 110 V. The heating element is designed
to convey a current with a maximum value of
10.5 A.
Find the rms current in the heating element.
Part 2 of 2
Find the resistance of the heating element.
Holt SF 22C 04
33:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
An audio ampliﬁer provides an alternating
rms potential diﬀerence of 15.0 V. A loudspeaker connected to the ampliﬁer has a resistance of 10.4 Ω.
What is the rms current in the speaker?
Part 2 of 3
What is the maximum value of current?
Part 3 of 3
What is the maximum value for the potential Holt SF 22C 05
33:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
An AC generator has a maximum potential
diﬀerence output of 155 V.
Find the rms potential diﬀerence output.
Part 2 of 2
Find the rms current in the circuit when the
generator is connected to a 53 Ω resistor.
Holt SF 22Rev 26
33:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The maximum potential diﬀerence across
certain heavyduty appliances is 340 V. The
total resistance of an appliance is 120 Ω.
Find the rms potential diﬀerence across the
appliance.
Part 2 of 2
Find the rms current in the appliance. Chapter 33, section 5, Capacitors in an AC Circuit
Holt SF 22C 06
33:05, highSchool, numeric, < 1 min, normal.
The largest potential diﬀerence that can
be placed across a certain capacitor at any
instant is 451 V.
What is the largest rms potential diﬀerence that can be placed across the capacitor
without damaging it? 171 Chapter 33, section 7, The RLC Series Circuit
RC and LC Circuits 05
33:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Consider the following circuit.
After leaving the switch at the position “a”
for a long time, move the switch from “a”
to “b”. There will be the usual LC circuit
oscillations. B2. The charge on the left plate of C is zero.
B3. The charge on the left plate of C is negative.
Let the time when the switch is moved from
a to b be at t = 0.
Which pair of choices below best describes
5
the situation at t = T , where T is the period
8
of oscillations in LC circuit? and B2
and B3 4. A2 and B1 5. A2 and B2 6. A2 Sb and B1 3. A1 C 1. A1
2. A1 L and B3 7. A3 and B1 8. A3 and B2 9. A3 and B3 a E R What is the maximum current?
1. Imax E√
=
LC
R 2. Imax = E
3. Imax L
C √
= E LC 4. Imax = E
5. Imax = E
R 6. Imax = E
R 1
LC 7. Imax = E
8. Imax = E
R L
C
C
L
C
L Part 2 of 2
Consider the following statements:
A1. The current ﬂow is counterclockwise.
A2. The current is zero.
A3. The current ﬂow is clockwise.
B1. The charge on the left plate of C is positive. 172 Chapter 33, section 9, Power in an AC Circuit
Holt SF 22Rev 27
33:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
The maximum current that can pass
through a light bulb ﬁlament is 0.909 A when
its resistance is 182 Ω.
What is the rms current conducted by the
ﬁlament of the bulb?
Part 2 of 3
What is the rms potential diﬀerence across
the bulb’s ﬁlament? 173 Which of the following statements is true?
All energy is dissipated in R .
1. True
2. False
3. Cannot be determined
Part 2 of 3
The electric potential across C and L are 180◦
out of phase.
1. False
2. True Part 3 of 3
How much power does the light bulb use?
Holt SF 22Rev 28
33:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A 996 W hair dryer is designed to carry a
maximum current of 11.8 A.
How large is the rms current in the hair
dryer? 3. Cannot be determined
Part 3 of 3
The source E does no net work, since energy
lost in R is compensated by energy stored in
C and L .
1. False
2. True
3. Cannot be determined Part 2 of 2
What is the rms potential diﬀerence across
the hair dryer?
RLC TF Questions 02
33:09, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
This RLC circuit is driven by an oscillating
emf E .
C
L
R
E Chapter 33, section 13, The Transformer and Power Transmission 174 twice the primary voltage?
Conceptual 18 Q15
33:13, highSchool, multiple choice, < 1 min,
ﬁxed. 1. twice the current in the primary
2. half the current in the primary Consider a transformer.
What is true? 3. the same as the current in the primary 1. A transformer does not work with direct
current. 4. Sometimes these two currents are not
related to each other. 2. A transformer works with direct current. Hewitt CP9 25 E29
33:13, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 25 E21
33:13, highSchool, multiple choice, < 1 min,
ﬁxed. Can an eﬃcient transformer step up energy? Why does a transformer require alternating
voltage? 1. Yes; stepping up voltage is the same as
stepping up energy. 1. Due to economic reasons; alternating
voltage is cheaper to produce. 2. Yes, provided that the transformer is
made of special material such as amino acid
or other organic compounds. 2. If we apply a constant voltage to the
primary coil, it will burn out due to a short
circuit. 3. No; there is no such thing as an “eﬃcient
transformer.” 3. Energy can be transferred more eﬃciently
if alternating voltage is used. 4. No; energy is conserved and cannot be
stepped up. 4. No speciﬁc reason; constant voltage would
work just as well.
5. Alternating voltage leads to electromagnetic induction which is necessary for the
transformer to work.
6. The magnetic ﬁeld produced by the primary coil can reach the secondary coil more
easily.
Hewitt CP9 25 E22
33:13, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the current in the secondary of
the transformer compare with the current in
the primary when the secondary voltage is 5. It cannot be determined.
6. Theoretically yes, but it is hard to build
such transformers in practice.
Hewitt CP9 25 P01
33:13, highSchool, numeric, < 1 min, normal.
The primary coil of a stepup transformer
draws 100 W.
Find the power provided by the secondary
coil.
Hewitt CP9 25 P02
33:13, highSchool, numeric, < 1 min, normal.
Part 1 of 3
An ideal transformer has 50 turns in its pri Chapter 33, section 13, The Transformer and Power Transmission
mary coil and 250 turns turns in its secondary
coil. 12 Vac is connected to the primary coil.
Find the ac voltage available at the secondary coil.
Part 2 of 3
Find the current in a 10 Ω device connected
to the secondary.
Part 3 of 3
Find the power supplied to the primary.
Hewitt CP9 25 P03
33:13, highSchool, numeric, < 1 min, normal.
A model electric train requires 6 V to operate.
If the primary coil of its transformer has
240 turns windings, how many windings
should the secondary have if the primary is
connected to a 120 V household circuit?
Holt SF 22D 01
33:13, highSchool, numeric, < 1 min, normal.
A stepdown transformer providing electricity for a residential neighborhood has exactly 2680 turns in its primary. When the
potential diﬀerence across the primary coil is
5850 V, the potential diﬀerence across the
secondary is 120 V.
How many turns are in the secondary?
(Round the answer to the nearest whole number.)
Holt SF 22D 02
33:13, highSchool, numeric, < 1 min, wordingvariable.
A stepup transformer used in an automobile has a potential diﬀerence across the
primary of 12 V and a potential diﬀerence
across the secondary of 2.0 × 104 V. There are
21 turns in the primary coil.
How many turns are in the secondary?
Holt SF 22D 03
33:13, highSchool, numeric, < 1 min, normal. 175 A stepup transformer for longrange transmission of electric power is used to create a
potential diﬀerence of 119340 V across the
secondary. The potential diﬀerence across
the primary is 117 V and the secondary has
25500 turns.
How many turns are in the primary?
Holt SF 22D 04
33:13, highSchool, numeric, < 1 min, wordingvariable.
A potential diﬀerence of 0.750 V is needed
to provide a large current for arc welding.
The potential diﬀerence across the primary of
a stepdown transformer is 117 V.
How many turns must be on the primary
for each turn on the secondary?
Holt SF 22D 05
33:13, highSchool, numeric, < 1 min, normal.
A television picture tube requires a high
potential diﬀerence, which in older models
is provided by a stepup transformer. The
transformer has 12 turns in its primary and
2550 turns in its secondary. A potential difference of 120 V is placed across the primary.
What is the output potential diﬀerence?
Holt SF 22D 06
33:13, highSchool, numeric, < 1 min, normal.
A stepdown transformer has 525 turns in
its secondary and 12500 turns in its primary.
The potential diﬀerence across the primary is
3510 V.
What is the potential diﬀerence across the
secondary?
Holt SF 22Rev 35
33:13, highSchool, numeric, < 1 min, wordingvariable.
A transformer is used to convert 120 V
to 9.0 V for use in a portable CD player.
The primary coil connected to the outlet has
640 turns.
How many turns does the secondary have? Chapter 33, section 13, The Transformer and Power Transmission
Holt SF 22Rev 36
33:13, highSchool, numeric, < 1 min, normal. 176 33:13, highSchool, numeric, < 1 min, wordingvariable. A transformer has 22 of wire in its primary
and 88 in its secondary. A potential diﬀerence
of 110 V ac is applied to the primary.
What is the output potential diﬀerence? A ideal transformer shown in the ﬁgure
below having a primary with 20 turns and
secondary with 12 turns.
The load resistor is 50 Ω.
The source voltage is 105 Vrms . Holt SF 22Rev 41
33:13, highSchool, numeric, < 1 min, wordingvariable.
The potential diﬀerence in the lines that
carry electric power to homes is typically 20.0
kV.
How many turns must be on the primary
for each turn on the secondary if the output
potential diﬀerence is 117 V? (Round the
answer to the nearest whole ratio.)
Holt SF 22Rev 43
33:13, highSchool, numeric, > 1 min, normal.
Part 1 of 2
A generator supplies 5000 kW of power.
The output potential diﬀerence is 4500 V before it stepped up to 510 kV .
The electricity travels 410 miles (644000 m)
through a transmission line that has a resistance per unit length of 0.00045 Ω/m .
How much power is lost through transmission of the electrical energy along the line?
Part 2 of 2
How much power would be lost through transmission if the generator’s output potential difference were not stepped up?
Holt SF 22Rev 45 50 Ω StepDown Transformer 03
33:13, highSchool, numeric, > 1 min, normal. 12 turns Holt SF 22Rev 40
33:13, highSchool, numeric, < 1 min, normal. 20 turns A pair of adjacent coils has a mutual inductance of 1.06 H. The current in the primary
circuit decreases by 9.50 A in a time interval
of 0.0336 s.
Determine the average emf induced in the
secondary circuit. 105 Vrms A transformer is used to convert 120 V to
17 V in order to power a toy electric train.
There are 480 turns in the primary.
How many turns should there be in the
secondary? What is the rms electric potential across
the 50 Ω load resistor? Chapter 34, section 2, Plane Electromagnetic Waves
Conceptual 19 09
34:02, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
If the frequency of an electromagnetic wave
is 1 × 106 Hz what is the wavelength?
Part 2 of 2
What type of electromagnetic wave is this?
1. radio wave
2. microwave
3. infrared
4. visible light
5. ultraviolet
6. Xrays
7. gamma rays
Conceptual 19 Q02a
34:02, highSchool, multiple choice, < 1 min,
ﬁxed.
In what way are sound waves and radio
waves similar?
1. Both are traveling disturbances.
2. Both travel at the same speed.
3. Both require a medium.
4. Neither requires a medium. 177 Chapter 34, section 3, Speed of Electromagnetic Waves
Conceptual 19 01
34:03, highSchool, numeric, > 1 min, normal.
Radio and TV transmissions are being
emitted into space, so Star Trek episodes are
streaming out into the universe. The nearest
star is 9.5 × 1017 m meters away.
If civilized life exists on a planet near this
star, how long will they have to wait for the
next episode? 178 How long is the wavelength of the radiation
at the end of the range?
Conceptual 19 05
34:03, highSchool, numeric, > 1 min, ﬁxed.
What is the frequency of a microwave from
a typical microwave oven?
Conceptual 19 07
34:03, highSchool, numeric, > 1 min, ﬁxed. Conceptual 19 02
34:03, highSchool, numeric, > 1 min, normal. If an Xray has a wavelength of 5 nm, what
is its frequency? Part 1 of 2
If the frequency of the wave used by your
favourite station is 94.1 Megahertz, what is
the wavelength? Conceptual 19 Q03
34:03, highSchool, multiple choice, < 1 min,
ﬁxed. Part 2 of 2
If the station is 50 km away, how long does it
take for the radio waves to reach you from the
station?
Conceptual 19 03
34:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The FM radio band in most places
goes from frequencies of about 88 MHz to
108 MHz.
How long is the wavelength of the radiation
at the beginning of the range?
Part 2 of 2
How long is the wavelength of the radiation
at the end of the range?
Conceptual 19 04
34:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The AM radio band in a particular area has
a frequency range of 535 KHz to 1610 KHz.
How long is the wavelength of the radiation
at the beginning of the range?
Part 2 of 2 Suppose a sound wave and a light wave have
the same frequency.
Which of the following is true?
1. The light wave has a longer wavelength
and has the greater speed.
2. The light wave has a longer wavelength
and has the slower speed.
3. The light wave has a shorter wavelength
and has the greater speed.
4. The light wave has a shorter wavelength
and has the slower speed.
5. The sound wave has a longer wavelength
and has the greater speed.
6. The sound wave has a longer wavelength
and has the slower speed.
7. The sound wave has a shorter wavelength
and has the greater speed.
Hewitt CP9 26 E11
34:03, highSchool, multiple choice, < 1 min,
ﬁxed.
At what speed does the radio wave travel? Chapter 34, section 3, Speed of Electromagnetic Waves
1. at the speed of light
2. at the speed of sound
3. at a speed between the speed of light and
the speed of sound
4. faster than visible light
5. slower than the sound 179 3. There is no diﬀerence between the speed
of light in glass and in a vacuum.
4. It cannot be judged because we don’t
know what kind of glass it is.
5. For colorless glass, the light speed is
higher than in a vacuum; for colored glass,
the light speed is lower than in vacuum.
Holt SF 14A 01
34:03, highSchool, numeric, > 1 min, ﬁxed. 6. More information is needed.
Hewitt CP9 26 R13
34:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How is the wavelength of light related to its
frequency?
1. Waves of low frequency have long wavelengths.
2. Waves of high frequency have long wavelengths.
3. Sometimes waves of low frequency have
long wavelengths; sometimes waves of high
frequency have long wavelengths.
4. For visible light wavelength has an inverse
relationship with frequency; for invisible light,
it has a direct relationship.
5. There is no relationship between frequency and wavelengths at all.
Hewitt CP9 26 R21
34:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the average speed of light in glass
compare with its speed in a vacuum?
1. The speed of light in glass is higher.
2. The speed of light in glass is lower. Gammaray bursters are objects in the universe that emit pulses of gamma rays with
high energies. The frequency of the most energetic bursts has been measured at around
3.0 × 1021 Hz.
The speed of light is 3 × 108 m/s.
What is the wavelength of these gamma
rays?
Holt SF 14A 02
34:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
FM radio bands range from 88 MHZ
through 108 MHz.
The speed of light is 3 × 108 m/s.
What is the wavelength for the FM radio
band at 88 MHz?
Part 2 of 2
What is the wavelength for the FM radio band
at 108 MHz?
Holt SF 14A 03
34:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Shortwave radio is broadcast between 3.50
MHz and 29.7 MHz .
The speed of light is 3 × 108 m/s.
What is the wavelength at 3.50 MHz ?
Part 2 of 2
What is the wavelength at 29.7 MHz ? Chapter 34, section 3, Speed of Electromagnetic Waves
Holt SF 14A 04
34:03, highSchool, numeric, > 1 min, wordingvariable. 4. a function of the distance from the
source.
5. a function of the size of the source. What is the frequency of an electromagnetic wave if it has a wavelength of 1.0 km?
The speed of light is 3 × 108 m/s.
Holt SF 14Rev 10
34:03, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
The compound eyes of bees and other insects are highly sensitive to light in the ultraviolet portion of the spectrum, particularly
light with frequencies between 7.5 × 1014 Hz
and 1.0 × 1015 Hz.
The speed of light is 3 × 108 m/s.
What is the largest wavelength to which
these frequencies correspond?
Part 2 of 2
What is the smallest wavelength?
Holt SF 14Rev 11
34:03, highSchool, numeric, > 1 min, wordingvariable.
The brightest light detected from the star
Antares has a frequency of about 3.0 × 1014
Hz.
The speed of light is 3 × 108 m/s.
What is the wavelength of this light?
Maxwells Prediction
34:03, highSchool, multiple choice, < 1 min,
ﬁxed.
According to Maxwell’s equation, the speed
of light in a vacuum is
1. greater for visible light than for radio
waves.
2. greater for radio waves than for visible
light.
3. independent of frequency. 180 Chapter 34, section 4, Energy Carried by Electromagnetic Waves: Poynting Vector 181 ﬁxed.
Concept 30 05
34:04, highSchool, multiple choice, < 1 min,
ﬁxed.
If we double the frequency of light, we double the energy of each of its photons.
If we instead double the wavelength of light,
what happens to the photon energy?
1. Doubled
2. Halved
3. Quadrupled
4. No change
Concept 30 14
34:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which has the greatest energy?
1. A photon of infrared light
2. A photon of visible light
3. A photon of ultraviolet light
4. They have the same energy.
Conceptual 19 08
34:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which has the greatest energy among the
following? Part 1 of 2
Compare the energy of visible light and
ultraviolet light.
1. Visible light has more energy than ultraviolet light.
2. Visible light has less energy than ultraviolet light.
3. They have same energy.
Part 2 of 2
What determines the energy of electromagnetic waves?
1. The higher the frequency of the radiation
the greater its energy
2. The lower the frequency of the radiation
the greater its energy
Figuring Physics 32
34:04, highSchool, multiple choice, > 1 min,
wordingvariable.
Maxwell’s equations tell us that a changing magnetic ﬁeld induces a changing electric
ﬁeld, and vice versa in turn, to produce an
electromagnetic wave.
Such ﬁeld induction depends on changes
both with respect to time and with respect
to distance — so it depends on speed. The
speed of propagation of ﬁelds inducing and
reinducing each other is c , the speed of light.
E 1. a wavelength of 90 nm
2. a wavelength of 2 nm
3. a wavelength of 45 nm B 4. a wavelength of 23 nm
Conceptual 19 Q09
34:04, highSchool, multiple choice, < 1 min, Are propagation speeds faster than c consistant with conservation of energy? Chapter 34, section 4, Energy Carried by Electromagnetic Waves: Poynting Vector
1. no, because the each changing ﬁeld would
produce an everincreasing ﬁeld strength.
2. no, because of special relativity.
3. no, because of general relativity.
4. no, because in a vacuum light has to travel
at a velocity less than or equal to c to conserve
energy.
Incandescent Lamp Filament 01
34:04, highSchool, numeric, > 1 min, normal.
The ﬁlament of an incandescent lamp has a
150 Ω resistance and carries a direct current
of 1 A. The ﬁlament is 8 cm long and 0.9 mm
in radius.
Calculate the Poynting vector at the surface
of the ﬁlament.
Poynting Vector again
34:04, highSchool, multiple choice, < 1 min,
ﬁxed.
For an electromagnetic wave the direction
of the vector E × B gives the direction of
1. the electric ﬁeld. 182 Part 2 of 2
What is the total power radiated by the sun?
Traveling EMwave M
34:04, highSchool, multiple choice, > 1 min,
ﬁxed.
A snapshot at time t = 0 of the electric
ﬁeld for a plane electromagnetic wave with
angular velocity ω traveling in the y direction
at velocity c is shown.
propagation direction
E
z
y
x What is the accompanying magnetic ﬁeld
at time t if the electric ﬁeld has amplitude
E0 ?
1. B = − E0
ˆ
cos(k y − ω t) k .
c 2. B = +c E0 sin(k y − ω t) ˆ.
ı
ˆ
3. B = +c E0 sin(k y + ω t) k . 2. the magnetic ﬁeld.
3. wave propagation. 4. B = − E0
cos(k y − ω t) ˆ.
ı
c 4. the electromagnetic force on a proton. 5. B = + E0
cos(k y − ω t) ˆ.
ı
c 5. the emf induced by the wave.
Solar EM Waves
34:04, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Use the radius of the sun 7 × 108 m and the
distance to the Earth of 1 AU= 1.5 × 1011 m
to determine the amplitude of the electric
ﬁeld at the surface of the sun from the solar
radiation content of 1400 W/m2 measured at
the surface of the Earth. Travelling EMwave
34:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 4
A snapshot at time t = 0 of the electric
ﬁeld for a plane electromagnetic wave with
angular velocity ω traveling in the y direction
at velocity c is shown. Chapter 34, section 4, Energy Carried by Electromagnetic Waves: Poynting Vector
E
z propagation direction
y What happens to the the wavelength of the
wave if the angular velocity ω of the wave is
decreased?
1. λ increases. x 2. λ decreases.
3. λ remains the same.
What is the accompanying magnetic ﬁeld
at time t if the electric ﬁeld has amplitude
E0 ?
1. B = − E0
ˆ
cos(k y − ω t) k .
c 2. B = +c E0 sin(k y − ω t) ˆ.
ı
ˆ
3. B = +c E0 sin(k y + ω t) k .
4. B = − E0
cos(k y − ω t) ˆ.
ı
c 5. B = + E0
cos(k y − ω t) ˆ.
ı
c Part 2 of 4
What happens to the ratio of the electric to
magnetic ﬁeld if the angular velocity ω of the
wave is decreased?
E0
increases.
B0
E0
2.
decreases.
B0
E0
remains the same.
3.
B0 1. Part 3 of 4
What happens to the velocity of the wave
if the angular velocity ω of the wave is decreased?
1. v increases.
2. v decreases.
3. v remains the same.
Part 4 of 4 183 Chapter 34, section 5, Momentum and Radiation Pressure O r n = 1.33 D Find the intensity I of the incident light at
D.
1. I =
2. I =
3. I =
4. I =
5. I =
6. I =
7. I =
8. I =
9. I =
10. I = Part 1 of 2
A polymer ﬁlm with a refraction index of
1.33 is impinged by a laser light from the left. Right interface Part 1 of 2
A point source at O emits light isotropically. Denote the power which the point
source radiates by P . A small ﬂat surface is placed at D, which is a distance r
from O. This surface has an area A and
is perpendicular to the radial vector OD. Laser on a polymer ﬁlm
34:05, highSchool, multiple choice, > 1 min,
ﬁxed. Left interface Intensity from a light source
34:05, highSchool, numeric, > 1 min, normal. 184 P
4 π r2
P
2 π r2
P
π r2
P
3 π r2
P
6 π r2
P
A
P
2A
P
3A
2P
3A
P
4A Part 2 of 2
Consider the setup described in Part 1, where
1
the surface absorbs of the light.
3
If P = 120 W, r = 1 m, and A = 1 mm2 ,
ﬁnd the average pressure on the surface. Assuming the ﬁlm is 100% transparent,
what will be the direction of forces?
1. → ←
2. no forces on either interfaces
3. → →
4. ← →
5. ← ←
6. left no force, right →
7. left ←, right no force
8. left →, right no force
9. left no force, right ←
Part 2 of 2
Now the left interface is coated with a thin
metal ﬁlm to provide 50% reﬂectivity. The
right interface remains completely transparent.
What will be the direction of forces on the
two interfaces?
1. → ← Chapter 34, section 5, Momentum and Radiation Pressure 185 2. No forces on either interface
3. There will be a rightward force on the
polymer 3. → →
4. ← → 4. There will be a leftward force on the
polymer 5. ← ←
6. left no force, right →
7. left ←, right no force
8. left →, right no force
9. left no force, right ←
Momentum and Transmission
34:05, highSchool, multiple choice, < 1 min,
ﬁxed.
A narrow beam of light passes through a
transparent plastic polymer with refractive
index 2.0. Consider the case in which there is
only one interface between the light and the
polymer. Furthermore, consider the case in
which there is 0% reﬂection at the interface
between the polymer and the air: the polymer
is 100
Upon entering the surface, the light’s wavelength, and thus, its momentum changes. Using what you know about momentum, determine what eﬀect the shining of the light will
have upon the polymer. n = 1. 0
n = 2. 0 total transmission 1. There will be a upward force on the polymer
2. There will be a downward force on the
polymer 5. There will be a force on the polymer
directed out of the page
6. There will be a force on the polymer
directed into the page
7. There will be no force on the polymer–
the light does not reﬂect, and thus does not
interact
8. The interaction of the light and the polymer cannot be determined
9. There will be no force on the polymer– the
angle of incidence must be nonzero in order
for a force to result Chapter 34, section 7, The Production of Electromagnetic Waves by an Antenna
Electron in a magnetic ﬁeld
34:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
An electron in a uniform magnetic ﬁeld B
in the z direction describes a cyclotron orbit
in the xy plane. A physicist along the y axis
at point O is trying to detect electromagnetic
radiation from the circulating electron using
an electric dipole antenna connected in series
to an inductor L, variable capacitor C and
light bulb of resistance R. As she reorients
the antenna and tunes the capacitor the light
bulb suddenly lights up.
z
B receiving
antenna C
R O R2 m
.
eBL
e2 B 2 L
.
4. C =
m2 3. C = 5. Need the electron’s velocity
Oscillating Current 01
34:07, highSchool, multiple choice, > 1 min,
ﬁxed.
A radio transmitter drives an oscillating
current driven back and forth along the z axis
in the aerial antenna wire as shown below.
z
I
y
x y e V II L x 186 antenna can be
oriented in any direction Along which direction should she orient the
antenna to maximize the brightness of the
bulb?
1. along the ˆ direction
ı
2. along the ˆ direction ˆ
3. along the k direction
4. at any orientation perpendicular to the ˆ direction
ˆ
5. at any orientation perpendicular to the k
direction
Part 2 of 2
How does she tune the capicitor to maximize
the bulb’s brightness?
eB R
.
m
m2
2. C = 2 2 .
eBL 1. C = IV
transmitter III Five linear receiving antennas are positioned with their centers at equal distances
d from the center of the transmitter as follows
I. Horizontal orientation, perpendicular to
ˆ
the antenna, positioned at d, in the +k
direction.
II. Vertical orientation, parallel to the antenna, positioned at d, in the +ˆ direcı
tion.
III. Horizontal orientation, perpendicular to
the antenna, positioned at d, in the −ˆ direction.
IV. Vertical orientation, parallel to the antenna, positioned at d, in the −ˆ direcı
tion.
V. Horizontal orientation, perpendicular to Chapter 34, section 7, The Production of Electromagnetic Waves by an Antenna
the antenna, positioned at d, in the +ˆ direction.
Which antennas receive the strongest
signal?
1. I IV. Positioned at d, in the −ˆ direction, facı
ing along z .
ˆ
V. Positioned at d, in the +ˆ direction, fac
ing along x.
ˆ
Which antennas receive the strongest signal? 2. I, II, and IV 1. II and V 3. II, IV, V, and III 2. I 4. V and III 3. II 5. II and IV 4. IV Oscillating Current 02
34:07, highSchool, multiple choice, > 1 min,
ﬁxed. 5. V A radio transmitter drives an oscillating
current back and forth along the z axis in the
aerial antenna wire as shown below.
z
I
y
x 7. II and IV V II transmitter
IV III Five circular receiving antennas are positioned with their centers at equal distances d
from the center of the transmitter as follows
ˆ
I. Positioned at d, in the +k direction, facing along x.
ˆ
II. Positioned at d, in the +ˆ direction, facı
ing along y .
ˆ
III. Positioned at d, in the −ˆ direction, fac
ing along y .
ˆ 187 6. III 8. I, II, V and III
9. II and III
10. I and V Chapter 34, section 8, Properties of Electromagnetic Waves 188 and sound waves do not.
Concept 20 06
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. 3. Sound waves travel faster than radio
waves. Suppose a sound wave and an electromagnetic wave have the same frequency.
Which has the longer wavelength? Conceptual 19 Q05
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. 1. the electromagnetic wave
2. the sound wave Why would walking down a ﬂight of stairs
be very hazardous if our eyes detected only
infrared? (Hint: What does the amount of
infrared light emitted by an object indicate?) 3. They have the same wavelength.
4. It depends on the speed of the sound
wave. 1. because infrared is an indicator of an
object’s temperature.
2. because infrared cannot travel far. Conceptual 19 Q01
34:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Compare waves on a pond and electromagnetic waves.
1. A wave on a pond is a mechanical wave
which requires a medium to travel.
2. A wave on a pond is a mechanical wave
which doesn’t require a medium to travel.
3. A wave on a pond is an electromagnetic
wave which requires a medium to travel
4. A wave on a pond is an electromagnetic wave which doesn’t require a medium
to travel.
Conceptual 19 Q02
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. Conceptual 19 Q10
34:08, highSchool, multiple choice, < 1 min,
ﬁxed.
A person is just as likely to get sunburned
on a cloudy day as on a sunny day.
Does this evidence support the hypothesis
that ultraviolet light, not visible light, causes
sunburn?
1. No.
2. Yes.
Conceptual 19 Q12
34:08, highSchool, multiple choice, < 1 min,
ﬁxed.
If someone asked you to prove that electromagnetic waves travel in a vacuum, what
would you say?
1. We see stars and planets in the sky. In what way do sound waves diﬀer from
radio waves?
1. Sound waves require a medium to travel
and radio waves do not. 2. We can see polarized light.
3. We can see diﬀracted light.
4. We can see refracted light. 2. Radio waves require a medium to travel Chapter 34, section 8, Properties of Electromagnetic Waves
Conceptual 20 Q07
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. 189 4. IV only
5. I and II only In a nighttime infrared image of a heated
house, the windows glow brightly. However,
textbooks claim that glass is opaque to infrared radiation.
This would be 6. I and III only
7. II and IV only
8. III and IV only I)
II)
III)
IV) due to warm windows;
due to cold walls;
due to people’s heat signature;
due to detection of ﬁre place from the
window; 1. I and II only 9. All of these
10. None of these
Conceptual 20 Q16
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. 2. I and III only
3. II and III only
4. I only
5. IV only
6. None of these
Conceptual 20 Q14
34:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Why do people wear lightcolored clothing
in summer and darkcolored clothing in winter? Which of these are NOT true about stainedglass windows at night?
I) Stained glass absorbs certain colors selectively.
II) No light comes through from the outside
so it looks gray.
III) A red pane looks red when light shines
through it.
IV) Stainedglass windows look bright from
the outside.
V) Dark light that passes through stainedglass windows makes it look gray.
1. I only
2. II only I) Dark clothing absorbs more light so it
can keep you warmer;
II) The absorbed light is converted to kinetic energy of the atoms in the clothing;
III) Dark clothing is usually thicker;
IV) Light clothing is lighter. 3. III only
4. IV only
5. V only
6. I and IV only 1. I only
7. IV and V only
2. II only
8. III and IV only
3. III only Chapter 34, section 8, Properties of Electromagnetic Waves
9. I and V only
10. None of these 190 4. None of these
5. All of these Conceptual 20 Q18
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 26 E03
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. What kind of electromagnetic radiation can
be detected by a human body? What is the fundamental source of electromagnetic radiation? I)
II)
III)
IV) visible light
infrared light
ultraviolet light
all other light 1. any charge
2. current
3. voltage 1. I only
4. an accelerating charge
2. II only
5. None of these
3. III only
4. I and II only Hewitt CP9 26 R03
34:08, highSchool, multiple choice, < 1 min,
ﬁxed. 5. I and III only
What produces an electromagnetic wave?
6. I, II and III only
1. charges
7. III and IV only
2. static magnetic ﬁeld
8. II, III and IV only
3. light
9. I and IV only
4. static electronic ﬁeld
10. All of these
5. electricity
Figuring Physics 24
34:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of these continually emits electromagnetic radiation?
1. a unlit ﬂashlight bulb
2. a hot steam radiator
3. a tray of ice cubes 6. None of these Chapter 34, section 9, The Spectrum of Electromagnetic Waves 191 ﬁxed.
Concept 30 03
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Green light is emitted when electrons in
a substance make a particular energylevel
transition.
If blue light were instead emitted from
the same substance, would it correspond to
a greater or smaller change of energy in an
atom? Part 1 of 2
White light is the combination of all frequencies of electromagnetic waves in the visible spectrum. In a vacuum, all the frequencies of light travel at the same speed. Suppose
for a moment that lower frequencies traveled
slower than higher frequencies.
What would a distant star look like?
1. brighter than before 1. Greater energy change 2. dimmer than before 2. Smaller energy change 3. same 3. The same energy change
4. More information is needed.
Conceptual 19 06
34:09, highSchool, multiple choice, < 1 min,
wordingvariable. Part 2 of 2
If the star suddenly disappeared, what would
be the color of the last light that you would
see from the star?
1. red
2. yellow Part 1 of 2
What is the wavelength for orange light? 3. green 1. 620 nm 4. blue 2. 530 nm 5. violet 3. 700 nm 6. indigo 4. 580 nm 7. orange Part 2 of 2
Convert this to meters.
1. 6.2 × 10−7 m
2. 5.3e − 07 m
3. 7e − 07 m
4. 5.8e − 07 m
Conceptual 19 Q04
34:09, highSchool, multiple choice, < 1 min, Conceptual 19 Q06
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
An object that looks white when exposed
to sunlight reﬂects all colors of light.
What does a white object look like when it
is exposed to red light?
1. A white object will look red when exposed
to red light. Chapter 34, section 9, The Spectrum of Electromagnetic Waves
2. A white object will look yellow when
exposed to red light.
3. A white object will look the same when
exposed to red light.
Part 2 of 2
What does a red object look like when it is
exposed to blue light?
1. A red object will appear dark when exposed to blue light
2. A red object will appear bright when
exposed to blue light 192 2. Radiowaves have lower frequency, same
speed, and longer wavelength than ultraviolet
light.
3. Radiowaves have higher frequency, same
speed, and longer wavelength than ultraviolet
light.
4. Radiowaves have lower frequency, faster
speed, and shorter wavelength than ultraviolet light.
Conceptual 19 Q11
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. Conceptual 19 Q07
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 3
Compare radio waves and sound waves. Comparing microwaves and visible light,
which of the following is true? 1. electromagnetic wave; it travels at the
speed of light 1. Microwaves have lower frequency, slower
speed, and longer wavelength than visible
light. 2. electromagnetic wave; it does not travel
at the speed of light 2. Microwaves have lower frequency, same
speed, and longer wavelength than visible
light.
3. Microwaves have higher frequency, same
speed, and longer wavelength than visible
light.
4. Microwaves have lower frequency, faster
speed, and shorter wavelength than visible
light.
Conceptual 19 Q08
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Comparing radio waves and ultraviolet
light, which of the following is true?
1. Radiowaves have lower frequency, slower
speed, and longer wavelength than ultraviolet
light. 3. mechanical wave; it travels at the speed
of light
4. mechanical wave; it does not travel at the
speed of light
Part 2 of 3
What kind of wave is a sound wave?
1. electromagnetic wave; it travels at the
speed of light.
2. electromagnetic wave; it does not travel
at the speed of light.
3. mechanical wave; it travels at the speed
of light.
4. mechanical wave; it does not travel at the
speed of light.
Part 3 of 3
What is the diﬀerence between radio waves Chapter 34, section 9, The Spectrum of Electromagnetic Waves
and light waves?
1. The light waves have shorter wavelength. 193 7. violet light.
Hewitt CP9 26 E04
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. 2. The light waves have longer wavelength.
What has the longest wavelength?
3. The light waves travels faster.
1. light waves
4. The radio waves are mechanical waves.
2. X rays
Conceptual 19 Q13
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. 3. radio waves
4. ultraviolet light waves What is the diﬀerence between gamma rays
and infrared rays?
1. Gamma rays have a higher frequency and
shorter wavelength.
2. Gamma rays have a lower frequency and
shorter wavelength.
3. Gamma rays have a higher frequency and
longer wavelength. 5. gama rays
Hewitt CP9 26 E05
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
What has the highest frequency?
1. ultraviolet light
2. infrared light 4. Gamma rays have a lower frequency and
longer wavelength. 3. X ray EM Waves
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. 4. visible light Of the following which type of electromagnetic wave has the longest wavelength? 6. radio wave 1. Xrays. 5. gamma ray Hewitt CP9 26 R08
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. 2. AM radio waves.
3. red light.
4. Gamma rays. What is the principal diﬀerence between a
radio wave and visible light?
1. Radio waves have lower frequencies than
visible light waves. 5. microwaves.
6. FM radio waves. 2. Radio waves are not electromagnetic
waves. Chapter 34, section 9, The Spectrum of Electromagnetic Waves
3. Radio waves are sound waves.
4. Light is more powerful than radio waves.
5. They travel at diﬀerent speeds.
Hewitt CP9 26 R11
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
What color does visible light of the lowest
frequency appear? Of the highest? 194 Hewitt CP9 27 E11
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
A spotlight is coated so that it won’t transmit yellow light from its whitehot ﬁlament.
What color is the emerging beam of light?
1. blue
2. red
3. green 1. red for lowest; blue for highest
4. yellow
2. yellow for lowest; green for highest
4. black
3. red for lowest; violet for highest
4. green for lowest; red for highest Hewitt CP9 27 E20
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. 5. violet for lowest; red for highest
6. blue for lowest; green for highest
Hewitt CP9 27 E08
34:09, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 3
What color is obtained when you mix yellow
light and blue light?
1. green
2. white The radiation curve of the sun shows that
the brightest light from the sun is yellowgreen.
Why then do we see the sun as whitish
instead of yellowgreen? 3. cyan
4. red
5. magenta 1. The yellowgreen light has very strong
intensity, so when it arrives at our eyes, we
can only feel it as strong white light. 6. blue
7. yellow 2. All colors mix to produce the white light
we see.
3. When sunlight passes through the air,
yellowgreen components are absorbed by the
air.
4. Outside the Earth you will see yellowgreen light of the sun. Part 2 of 3
What color should be combined with green
light to produce white light?
1. green
2. white
3. cyan Chapter 34, section 9, The Spectrum of Electromagnetic Waves 195 34:09, highSchool, numeric, > 1 min, normal.
4. red
The portion of the visible spectrum that
appears brightest to the human eye is around
560 nm in wavelength, which corresponds to
yellowgreen.
The speed of light is 3 × 108 m/s.
What is the frequency of 560 nm light? 5. magenta
6. blue
7. yellow
Part 3 of 3
What color is the mixture of magenta, yellow
and cyan light? Holt SF 14A 06
34:09, highSchool, numeric, > 1 min, normal.
What is the frequency of highly energetic
ultraviolet radiation that has a wavelength of
125 nm?
The speed of light is 3 × 108 m/s. 1. green
2. white
3. cyan Holt SF 14Rev 12
34:09, highSchool, numeric, > 1 min, wordingvariable. 4. red
5. magenta What is the wavelength of an FM radio
signal if the number on the dial reads 99.5
MHz? The speed of light is 3 × 108 m/s. 6. blue
7. yellow Holt SF 14Rev 13
34:09, highSchool, numeric, > 1 min, normal. Hewitt CP9 27 R01
34:09, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the relationship between the frequency of light and its color?
1. Lights of diﬀerent frequencies are perceived as diﬀerent colors.
2. The lowestfrequency light we detect appears to most people as the color violet.
3. The highestfrequency light we detect appears to most people as the color red.
4. There is no relationship between the frequency of light and its color.
5. None of these
Holt SF 14A 05 What is the wavelength of a radar signal
that has a frequency of 33 GHz? The speed of
light is 3 × 108 m/s. Chapter 35, section 1, The Nature of Light
Concept 20 07
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 196 we can still see it.
What diﬀerences in the properties of sound
and light does this indicate?
1. The bell jar is a good absorber of sound. From the stands of a race track why do you
notice smoke from the starter’s gun before you
hear it ﬁre?
1. The response time of eyes is shorter than
that of ears.
2. The gun smokes before making sound. 2. The bell jar is a good light transmitter.
3. Sound needs a material medium for its
transmission, while light does not.
4. Light needs a material medium for its
transmission, while sound does not. 3. Light travels about a million times faster
than sound in air. 5. There is a frequency shift of sound waves
when it passes through a vacuum. 4. Sound has a much longer wavelength than
light. Concept 20 24
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 5. Smoke spreads out quickly.
Concept 20 08
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
At Olympic competition, a microphone
picks up the sound of the starter’s gun and
sends an electric signal to speakers at every
runner’s starting block. Why?
1. There is a lot of noise in the stadium,
so the runners have diﬃculty hearing the gun
ﬁre.
2. The electronic starting gun does not rely
on time for sound to travel through air.
3. There is no unique reason for that.
4. Electric signals travel about a million
times faster than sound in air. What two physics mistakes occur in a science ﬁction movie that shows a distant explosion in outer space, where you see and hear
the explosion at the same time?
1. In outer space there is no material to
carry light; if there were, the sound would
reach you before the light.
2. In outer space there is no air to carry
sound; if there were, the fastermoving light
would reach you before the sound.
3. The explosion cannot occur in outer
space; if it could, the fastermoving light
would reach you before the sound.
4. The explosion cannot occur in outer
space; if it could, the sound would reach you
before the light.
5. None of these Concept 20 12
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
If a bell rings inside a bell jar, we can no
longer hear it when the air is pumped out, but Concept 20 25
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A rule of thumb for estimating the distance Chapter 35, section 1, The Nature of Light
in kilometers between an observer and a lightning stroke is to divide the number of seconds
in the interval between the ﬂash and the sound
by 3.
Is this rule correct? 197 (invisible infrared light or heat).
3. The missing energy strengthens the intensity of the light emitted.
4. None of these 1. No; the speed of light must be considered
in this problem.
2. No; the speed of sound varies rapidly with
altitude.
3. Yes; the speed of light is much greater
than the speed of sound. Conceptual 20 Q15
35:01, highSchool, multiple choice, < 1 min,
wordingvariable.
What is the frequency range of light seen
when you look at a white object?
1. all visible colors 4. Yes; the sound waves are longitudinal
waves. 2. no visible colors Concept 29 01
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 3. ultra violet colors Why can the sunlight that illuminates
the Earth be approximated by plane waves,
whereas the light from a nearby lamp cannot? 5. All possible colors 1. The sunlight is much stronger than the
light from a nearby lamp.
2. The Sun is much farther away from us
than the nearby lamp.
3. The light from a lamp is circular polarized
while the light from the Sun is not.
4. None of these
Concept 30 19
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. infrared colors 6. No possible colors
Conceptual 20 Q19
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why don’t planets twinkle the way stars
do?
I) The light coming from a planet is larger
in diameter.
II) The planets are larger than stars.
III) The view of the stars are obstructed by
other stars.
IV) The thermal ﬂuctuation in the atmosphere distorts the light of the stars.
1. II only If atoms of a substance absorb ultraviolet
light and emit red light, what becomes of the
“missing” energy? 2. III only
3. I and III only 1. The missing energy becomes the nuclear
energy of the substance.
2. The missing energy is light of other colors 4. I and IV only
5. II and III only Chapter 35, section 1, The Nature of Light 198 5. None of these
6. III and IV only
7. I, II and III only Hewitt CP9 26 E02
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 8. II, III and IV only
9. All of these
Conceptual 21 Q01
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The leaves of a tree are bright green.
What does a leaf’s absorption spectrum
look like?
1. The leaf would absorb all colors except
green.
2. The leaf would reﬂect all colors except
green.
3. The leaf would absorb sunlight.
4. The leaf would reﬂect sunlight. An excited atom emits a photon of a certain frequency. Then two photons of this
frequency ﬂy towards the atom.
Which of the following is likely to happen
next?
1. The atom will absorb both photons and
will become more excited than it originally
was.
2. The atom will absorb one of the photons
and will return to its excited state.
3. One of the two photons will knock an
electron out leaving an ion behind.
4. An atom will emit another photon of the
same frequency.
Hewitt CP9 26 P08
35:01, highSchool, numeric, > 1 min, normal. 5. None of these
Conceptual 21 Q02
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider objects that appear red.
Which is not true?
1. The red marker will be sharply peaked in
red as compared to other spectrum.
2. The red laser will be sharply peaked in
the red, with no other colors emitted.
3. The red coal will be peaked in the infrared, with some overlap into the visible spectrum.
4. The red sweater will have a peak in the
red, but not quite as sharp as the laser. Part 1 of 2
A certain bluegreen light has a wavelength
of 600 nm in air.
What is its wavelength in water, where light
travels at 75 % of its speed in air?
Part 2 of 2
What is its wavelength in Plexiglas, where
light travels at 67 % of its speed in air?
Hewitt CP9 27 E01
35:01, highSchool, multiple choice, < 1 min,
ﬁxed.
In a dress shop with only ﬂuorescent lighting, a customer insists on taking dresses into
the daylight at the doorway to check their
color.
Is she being reasonable?
1. No; the light in the dress shop is enough Chapter 35, section 1, The Nature of Light
for her to see the eﬀect.
2. Yes; in sunlight she can see much more
clearly. 199 2. Red for a hot day and yellow for a cold
day.
3. Green for a hot day and white for a cold
day. 3. Yes; under ﬂuorescent lighting, blue colors
will be accented. Colors appear quite diﬀerent
in sunlight. 4. Yellow for a hot day and blue for a cold
day. 4. No; if all customers make this kind of
request, the shop will lose control. 5. Green for a hot day and magenta for a
cold day. Hewitt CP9 27 E02
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 27 E04
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. Why will the leaves of a red rose be heated
more than the petals when illuminated with
red light? Why do we not list black and white as
colors? 1. The petals of a red rose will reﬂect red
light while the green leaves absorb red light.
The energy absorbed by the leaves tends to
increase their temperature. 1. People usually think black and white
should only reﬂect dark and light in a image.
They cannot represent the colorful world.
2. We have a subjective mind. 2. The cells in leaves are diﬀerent from those
in petals. They are more likely to absorb
heat. 3. Black should not be regarded as a color;
an early mistake in theory caused white to be
regarded as a color. 3. Red light will distort the DNA in leaves
and make it easy to receive energy, but for
petals this cannot happen. 4. Black means low intensity; white is the
result of an additive mixture of all the colors. 4. If the petals are illuminated with red
light, they will dry immediately and cannot
absorb additional light. Hewitt CP9 28 R18
35:01, highSchool, numeric, < 1 min, ﬁxed.
Which travels most slowly in glass? Hewitt CP9 27 E03
35:01, highSchool, multiple choice, < 1 min,
ﬁxed. 1. Red light
2. Blue light If sunlight were somehow green instead of
white, what color garment would be most
advisable on an uncomfortable hot day? On
a very cold day?
1. Blue for a hot day and green for a cold
day. 3. Violet light
4. Yellow light
5. Orange light
6. Brown light Chapter 35, section 1, The Nature of Light
7. Green light 200 Chapter 35, section 4, Reﬂection 201 3. Illuminated with green light
Hewitt CP9 27 E06
35:04, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Illuminated with blue light
5. Illuminated with orange light Fire engines used to be red. Now many of
them are yellowgreen.
Why was the color changed? Hewitt CP9 27 R32
35:04, highSchool, multiple choice, < 1 min,
ﬁxed. 1. Red color makes people feel nervous.
Why does water appear cyan?
2. They are most likely to be noticed if they
are yellowgreen; the eye is most sensitive to
that color. 1. Blue light from the sky is reﬂected by the
surface of water. 3. Red color is not easy to notice among
ﬁres. 2. Water molecules absorb more blue light
than any other light. 4. People got tired of the red color and a
color change was advised. 3. Water molecules resonate somewhat in
the visible red, causing red light to be absorbed easieer than blue light in water. Hewitt CP9 27 E09
35:04, highSchool, multiple choice, < 1 min,
ﬁxed. 4. At normal temperature water gives out
more blue light than any other light. What color would red cloth appear if it were
illuminated by sunlight or by cyan light only? 5. Water molecules strongly absorb infrared
light, which makes water appear cyan. 1. red and cyan correspondingly
2. red and blue correspondingly
3. blue and red correspondingly
4. red and red correspondingly Hewitt CP9 28 E04
35:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Trucks often have signs on their backs that
says: “If you can’t see my mirrors, I can’t see
you.”
Explain the physics here. 4. red and black correspondingly
Hewitt CP9 27 E23
35:04, highSchool, multiple choice, < 1 min,
ﬁxed.
In which of these cases will a ripe banana
appear black? 1. The truck is too big to let the mirror be
seen.
2. They all might have a bad mirror.
3. Light that takes a path from point A to
point B will take the same reverse path in
going from point B to point A. 1. Illuminated with red light
2. Illuminated with yellow light 4. If you are good driver, you may not need
a mirror. Chapter 35, section 4, Reﬂection
Hewitt CP9 28 R05
35:04, highSchool, numeric, < 1 min, ﬁxed.
What is the law of reﬂection? in the ﬁgure. A light ray strikes the horizontal mirror, reﬂects oﬀ the horizontal mirror,
impinges on the raised mirror, reﬂects oﬀ the
raised mirror, and proceeds in the righthand
direction. 1. Reﬂection is not consistent from an irregular surface. φ 2. The critical angle is 90 degrees.
3. The angle of incidence equals the angle of
refraction.
4. The angle of refraction equals the angle
of reﬂection.
5. The angle of reﬂection equals the angle of
incidence.
6. A faster light in the media results in a
larger reﬂective angle.
Hinged Mirrors 01
35:04, highSchool, numeric, > 1 min, wordingvariable.
The reﬂecting surfaces of two intersecting
ﬂat mirrors are at an angle of 56◦ , as shown in
the ﬁgure. A light ray strikes the horizontal
mirror at an angle of 53◦ with respect to the
mirror’s surface.
φ 56◦ 53◦ Figure is not drawn to scale.
Calculate the angle φ.
Holt SF 14Rev 53
35:04, highSchool, numeric, > 1 min, normal.
The reﬂecting surfaces of two intersecting
ﬂat mirrors are at an angle of 57 ◦ , as shown 202 57◦
Figure is not drawn to scale.
Calculate the angle φ. Chapter 35, section 5, Transmission and Refraction
Air Liquid Interface 01
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Consider a light ray which enters from air
to a liquid, where the index of refraction of
√
the liquid is given by n = 2.
Consider the following three ratios, where
each is deﬁned by the speciﬁed quantity in
the liquid, λ , f , and v , to that in the air,
λ, f, and c.
light ray
n=1
n= √ 2 Air 1.
2.
3.
4.
5. λ
λ
λ
λ
λ
λ
λ
λ
λ
λ λ
?
λ =1 = 1
2
√ Air Liquid Interface 02
35:05, highSchool, numeric, < 1 min, normal.
Part 1 of 3
Consider a light ray which enters from air
to a liquid, where the index of refraction of
the liquid is given by n = 1.41421.
Consider the following three ratios, where
each is deﬁned by the speciﬁed quantity in
the liquid, λ , f , and v , to that in the air,
λ, f, and c.
light ray
Air 1.41421 1
=√
2 = f
=2
f n=1 Liquid What is the ratio of their wavelengths, 5. 203 Liquid What is the ratio of their wavelengths, Part 2 of 3
What is the ratio of their frequencies of oscilf
lations, ?
f
Part 3 of 3 2 =2 Part 2 of 2
What is the ratio of their frequencies of oscilf
lations, ?
f
f
1.
=1
f
f
1
2.
=√
f
2
f
1
3.
=
f
2
√
f
4.
=2
f λ
?
λ What is the ratio of the traveling speeds, v
?
c Air Liquid Interface 03
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider a light ray which enters from air
to a liquid, where the index of refraction of
√
the liquid is given by n = 2.
light ray
n=1
n= √ 2 What is the ratio
the liquid) Air
Liquid
v
(where v is deﬁned in
c Chapter 35, section 5, Transmission and Refraction
1.
2.
3.
4.
5. v
c
v
c
v
c
v
c
v
c 204 1
=√
2 mond? The speed of light in a vacuum is
3 × 108 m/s. =1 Conceptual 20 Q31
35:05, highSchool, multiple choice, < 1 min,
ﬁxed. =
= 1
2
√ 2 =2 Concept 28 E09
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
A person in a dark room looking through a
window can clearly see a person outside in the
daylight.
Why can the person outside not see the
person inside?
1. Window glass typically transmits about
92% of incident light, and the two surfaces
reﬂect about 8%.
2. The reﬂected outside light is more intense
than the inside light transmitted out.
3. People inside the room are more sensitive
to light than people outside.
4. Light is easier to transmit into the room
than transmit out. It sometimes happens that in cities located
on a coast a hazy white layer can be seen
over the city, but the layer is much less pronounced, or even absent, over the water.
Why does this happen?
1. the water is cooler than the city
2. the water is warmer than the city
3. due to reﬂection
4. due to refraction
5. None of these
Figuring Physics 23
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Light rays bend as they pass from air into
water at an angle (not 90 degrees). This is
refraction.
Incident
ray
Normal Conceptual 20 02
35:05, highSchool, numeric, < 1 min, ﬁxed. Air
Water If the speed of light through material Z is
2.5 × 108 m/s, what is this material’s index of
refraction? The speed of light in a vacuum is
3 × 108 m/s.
Conceptual 20 03
35:05, highSchool, numeric, < 1 min, ﬁxed.
Diamond has a high index of refraction at
about 2.4, which helps account for its sparkle.
How fast does light travel through a dia Refracted
ray
Which quantity doesn’t change when light
refracts?
1. average speed of light
2. index of refraction of the material Chapter 35, section 5, Transmission and Refraction 205 3. frequency of light
4. wavelength of light
Hewitt CP9 26 E18
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Is glass opaque to light of frequencies that
match its own natural frequencies?
1. No; the frequencies of glass are in magnitudes that no light frequencies will match.
2. No; the frequencies of glass are related to
the movements of glass atoms, which are almost not aﬀected by the frequencies of light.
3. Yes; the electrons in the glass will be
excited by the incident light, the frequecies
of which match the natural frequencies of the
glass.
4. Yes; the energy of light will be totally
converted into the energy of electrons in the
glass when the frequencies of light match the
natural frequencies of the glass.
5. More information is needed.
Hewitt CP9 27 R29
35:05, highSchool, multiple choice, < 1 min,
ﬁxed. When light strikes the surface between glass
and air perpendicularly, about 4% is reﬂected.
What is the percentage of light transmitted
through a plane of window glass?
Hewitt CP9 28 P06
35:05, highSchool, numeric, < 1 min, normal.
No glass is perfectly transparent. Mainly
because of reﬂections, about 92 % of light
passes through an average sheet of clear windowpane. The 8% loss is not noticed through
a single sheet, but through several sheets it is
apparent.
How much light is transmitted by a
“doubleglazed” window (one with two sheets
of glass)?
Hewitt CP9 28 R14
35:05, highSchool, multiple choice, < 1 min,
ﬁxed.
What causes refraction?
1. the existence of diﬀerent colors of light
2. the diﬀerence in the speed of light in
diﬀerent transparent media
3. the speed of light being higher than c in
some media
4. reﬂection What part of the electromagnetic spectrum
is most absorbed by water?
1. infrared
2. radio wave
3. red
4. microwave
5. ultraviolet
Hewitt CP9 28 P05
35:05, highSchool, numeric, < 1 min, normal. 5. None of these
Light enters from air to liquid
35:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Consider a light ray which enters from air
to a liquid, where the index of refraction of
√
the liquid is given by n = 2. Chapter 35, section 5, Transmission and Refraction
light ray
n=1
n= √ 2 Air
Liquid Denote the wavelength and the frequency
in the liquid by λ and f and those in the air
by λ and f . Choose the correct pair of ratios:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ
λ √
1
f
=,
=2
2
f
√
f
1
=√ ,
=2
f
2
√
f
= 1,
=2
f
√
√
f
= 2,
=2
f
√
f
= 2,
=2
f
1
f
=,
=1
2
f
f
1
=√ ,
=1
f
2
f
= 1,
=1
f
√
f
= 2,
=1
f
f
= 2,
=1
f 206 Chapter 35, section 6, The Law of Refraction 207 above, below or at the visible space station?
Concept 28 E25
35:06, highSchool, multiple choice, > 1 min,
ﬁxed. 1. Above
2. Directly at While standing on a bank you wish to spear
a ﬁsh in front of you.
Would you aim above, below, or directly at
the observed ﬁsh to make a direct hit? If,
on the other hand, you wished to zap the ﬁsh
with a laser beam of the same color as the
ﬁsh, how would you aim?
1. Below; above
2. Below; directly at
3. Above; above 3. Below
4. It depends on the movement of the space
station.
Concept 28 E38
35:06, highSchool, multiple choice, < 1 min,
ﬁxed.
When your eyes are submerged in water,
do light rays coming from water to your eyes
bend more, less, or the same as in air? 4. Above; below 1. More 5. None of these 2. Less Concept 28 E26
35:06, highSchool, multiple choice, > 1 min,
ﬁxed.
If while standing on a bank you wished to
zap a small blue ﬁsh out in front of you with
red laser beam, would you aim above, below,
or directly at the observed ﬁsh to make a
direct hit?
1. Slightly below the position
2. Slightly above the position
3. Directly at the ﬁsh
4. It depends on the movement of the water. 3. The same
4. It depends on the speed of the water.
Conceptual 20 Q26
35:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
In movies that involve a character lost in
the wilderness somewhere, you often see the
hero vainly try to spear a ﬁsh in a river or
tidal basin.
Even if his aim is good, how should he aim
to spear the ﬁsh?
1. below the ﬁsh
2. above the ﬁsh Concept 28 E30
35:06, highSchool, multiple choice, < 1 min,
ﬁxed. 3. on the heart
4. at the tail If you were to send a beam of laser light to a
space station above the atmosphere and just
above the horizon, would you aim the laser Part 2 of 2
Due to refraction, how deep is the ﬁsh in Chapter 35, section 6, The Law of Refraction
relation to its image?
1. deeper
2. shallower
3. at the point of the image
Hewitt CP9 26 E21
35:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Your friend says that you can get a sunburn
on a cloudy day but you cannot get a sunburn
even on a sunny day if you are behind glass.
Is he correct?
1. Yes; most of the solar spectrum can pass
through clouds.
2. No; clouds are full of water, which can
block most of the sunlight.
3. Yes; clouds are transparent to ultraviolet
light, which is the major reason for sunburn.
4. No; glass is transparent to ultraviolet
light, which is the major reason for sunburn.
5. None of these 208 of refraction.
Part 2 of 3
b) If the light travels from air to some medium
with an angle of incidence of 14.5◦ and an
angle of refraction of 9.80◦ , ﬁnd the refractive
index of the unknown medium.
Part 3 of 3
c) If the light travels from air to diamond
(n = 2.419) at an angle of incidence of 31.6◦ ,
ﬁnd the angle of refraction.
Holt SF 15A 03
35:06, highSchool, numeric, < 1 min, wordingvariable.
A ray of light of vacuum wavelength 550 nm
traveling in air enters a slab of transparent
material. The incoming ray makes an angle of
40.0◦ with the normal, and the refracted ray
makes an angle of 26.0◦ with the normal.
Find the index of refraction of the transparent material. (Assume that the index of
refraction of air for light of wavelength 550
nm is 1.00.)
Holt SF 15Rev 10
35:06, highSchool, numeric, < 1 min, wordingvariable. Holt SF 15A 01
35:06, highSchool, numeric, < 1 min, wordingvariable. Light passes from air into water at an angle
of incidence of 42.3◦ .
Find the angle of refraction in the water. Find the angle of refraction for a ray of light
that enters a bucket of water (n = 1.333) from
air at an angle of 25.0◦ to the normal. Holt SF 15Rev 11
35:06, highSchool, numeric, < 1 min, wordingvariable. Holt SF 15A 02
35:06, highSchool, numeric, < 1 min, wordingvariable. A ray of light enters the top of a glass of
water at an angle of 36.0◦ with the vertical.
What is the angle between the refracted ray
and the vertical? Part 1 of 3
An incoming ray of light has a vacuum
wavelength of 589 nm.
a) If the light travels from ﬂint glass
(n = 1.66) to crown glass (n = 1.52) with
an angle of incidence of 25.0◦ , ﬁnd the angle Holt SF 15Rev 12
35:06, highSchool, numeric, < 1 min, wordingvariable.
A narrow ray of yellow light from glowing Chapter 35, section 6, The Law of Refraction
sodium (λ 0 = 589 nm) traveling in air strikes
a smooth surface of water at an angle θi =
35.0◦ .
Find the angle of refraction, θr .
Holt SF 15Rev 13
35:06, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
A ray of light traveling in air strikes a ﬂat
2.00 cm thick block of glass (n = 1.50) at an
angle of 30.0 ◦ with the normal.
a) Trace the light ray through the glass, and
ﬁnd the angle of refraction for light passing
from air to glass.
Part 2 of 2
b) Find the angle of refraction for light passing
from glass to air.
Holt SF 15Rev 14
35:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The light ray shown in the ﬁgure makes
an angle of 20.0◦ with the normal line at the
boundary of linseed oil and water.
θ1
Air
◦ 20 Linseed oil
θ2 Water a) Find the angle θ1 . Note that n = 1.48
for the linseed oil.
Part 2 of 2
b) Find the angle θ2 .
Holt SF 15Rev 39
35:06, highSchool, numeric, < 1 min, wordingvariable. 209 The angle of incidence and the angle of refraction for light going from air into a material
with a higher index of refraction are 63.5◦ and
42.9◦ , respectively.
What is the index of refraction of this material?
Holt SF 15Rev 40
35:06, highSchool, numeric, < 1 min, wordingvariable.
A person shines a light at a friend who is
swimming underwater.
If the ray in the water makes an angle of
36.2◦ with the normal, what is the angle of
incidence?
Holt SF 15Rev 41
35:06, highSchool, numeric, < 1 min, wordingvariable.
What is the index of refraction of a material
in which the speed of light is 1.85 × 108 m/s?
Holt SF 15Rev 42
35:06, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
Light moves from ﬂint glass (n = 1.66) into
water at an angle of incidence of 28.7◦ .
a) What is the angle of refraction?
Part 2 of 2
b) At what angle would the light have to be
incident to give an angle of refraction of 90.0◦
Holt SF 15Rev 49
35:06, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The index of refraction for red light in water
is 1.331, and that for blue light is 1.340.
a) If a ray of white light traveling in air
enters the water at an angle of incidence of
83.0◦ , what is the angle of refraction for the
red component of light? Chapter 35, section 6, The Law of Refraction
Part 2 of 2
b) What is the angle of refraction for the blue
component of light?
Holt SF 15Rev 50
35:06, highSchool, numeric, > 1 min, wordingvariable.
A ray of light traveling in air strikes the
surface of mineral oil at an angle of 23.1◦ with
the normal to the surface.
If the light travels at 2.17 × 108 m/s through
the oil, what is the angle of refraction?
Holt SF 15Rev 51
35:06, highSchool, numeric, > 1 min, wordingvariable.
A ray of light traveling in air strikes the
surface of a liquid.
If the angle of incidence is 30.0◦ and the
angle of refraction is 22.0◦ , ﬁnd the critical
angle for light traveling from the liquid back
into the air.
Holt SF 15Rev 52
35:06, highSchool, numeric, < 1 min, wordingvariable.
The laws of refraction and reﬂection are the
same for sound and for light. The speed of
sound is 340 m/s in air and 1510 m/s in water.
If a sound wave that is traveling in air
approaches a ﬂat water surface with an angle
of incidence of 12.0◦ , what is the angle of
refraction?
Holt SF 15Rev 54
35:06, highSchool, numeric, < 1 min, wordingvariable.
A ray of light traveling in air strikes the
surface of a block of clear ice (n = 1.309) at
an angle of 40.0◦ with the normal. Part of the
light is reﬂected and part is refracted.
Find the angle between the reﬂected and
the refracted light. 210 Holt SF 15Rev 60
35:06, highSchool, numeric, > 1 min, wordingvariable.
A ﬂashlight on the bottom of a 4.00 m deep
swimming pool sends a ray upward and at an
angle so that the ray strikes the surface of the
water 2.00 m from the point directly above
the ﬂashlight.
What angle (in air) does the emerging ray
make with the water’s surface?
Holt SF 15Rev 61
35:06, highSchool, numeric, > 1 min, wordingvariable.
A submarine is 325 m horizontally out from
the shore and 115 m beneath the surface of
the water. A laser beam is sent from the
submarine so that it strikes the surface of the
water at a point 205 m m from the shore.
If the beam strikes the top of a building
standing directly at the water’s edge, ﬁnd the
height of the building. Chapter 35, section 7, Dispersion and Prisms 211 9. None of these
Conceptual 20 Q09
35:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Diamonds have a very high index of refraction.
How does this help to account for their
sparkle?
1. dispersion of light Conceptual 20 Q11
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If the atmosphere did not scatter light,
what would you see when you looked at the
daytime sky?
I) The sky would be dark;
II) Sunlight would pass right through atmosphere;
III) Light would be scattered to your eyes. 2. refraction
1. I and II only
3. light emitted by the diamond.
2. II and III only
4. None of these
3. I and III only
4. All of these
4. All of these
Part 2 of 2
The cutting of diamonds into facets increase
the sparkle you see. Consider the following
statements.
I) Internal reﬂection of light increases;
II) More light is transmitted with dispersion;
III) It enhances the appearance;
IV) Refraction occurs.
Which is/are NOT true? 5. None of these
Conceptual 20 Q12
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If the atom and molecules in the sky had
about 10 times their present size, what would
you expect the daytime sky to be?
1. much whiter 1. I only
2. blue
2. II only
3. dark
3. III only
4. red
4. IV only
5. None of these
5. I and II only
6. II and III only Conceptual 20 Q17
35:07, highSchool, multiple choice, < 1 min,
wordingvariable. 7. I and IV only
8. II and IV only For a house window to be as energy eﬃcient as possible, to which wavelengths of the
electromagnetic spectrum should it be trans Chapter 35, section 7, Dispersion and Prisms
parent?
1. visible light
2. all except visible light
3. ultra violet light 212 Hewitt CP9 27 E34
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If the sky on a certain planet in the solar system were normally orange, what color
would sunset be? 4. infrared light 1. red 5. All light 2. blue Conceptual 20 Q30
35:07, highSchool, multiple choice, < 1 min,
ﬁxed. 3. yellow Which parts of the electromagnetic spectrum, if any, scatter all wavelengths equally
from atoms and molecules? 5. white 1. gamma rays
2. alpha rays
3. beta rays
4. ultraviolet rays 4. orange 6. black
Hewitt CP9 27 E35
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Volcanic emissions put ﬁne ashes in the air
that scatter red light.
What color does a full moon appear
through these ashes? 5. infrared rays
1. red
Hewitt CP9 27 E27
35:07, highSchool, multiple choice, < 1 min,
ﬁxed. 2. cyan
3. yellow Why does the sky appear darker blue when
you are at high altitudes?
1. There is less sunshine at high altitudes
than at lower altitudes. 4. orange
5. brown
6. gray 2. There is less air above you and consequently less scattering of sunlight.
3. There are more redabsorbing molecules
in the air at high altitudes.
4. There is less air above you and consequently more scattering of sunlight. Hewitt CP9 27 E38
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If the atomosphere of the Earth were several
times thicker, what color would the ordinary
snowfall seem? Chapter 35, section 7, Dispersion and Prisms
1. red
2. blue 213 enter a glass block normal to its surface at the
same time.
After passing through the block, which
pulse exits ﬁrst? 3. white
1. Red light
4. green
2. Blue light
5. black
3. Yellow light
6. gray
4. Green light
Hewitt CP9 27 R25
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does the sun look red at sunrise and
sunset but not at noon?
1. Red light is easily transmitted through
the air since its frequency is the lowest.
At noon, sunlight travels through the least
amount of atmosphere with little scattering
of highfrequency light to the surface.
2. Red light is easily scattered through the
air since its frequency is the lowest. At noon,
sunlight travels through the least amount of
atmosphere with little transmission of highfrequency light to the surface.
3. The sun is colder at sunrise and sunset
than at noon.
4. The temperature at noon is warmer than
at sunrise and sunset.
5. Our eyes are more sensitive to the red
light at sunrise and sunset than at noon.
6. The sun itself is red at sunrise and sunset,
but is yellow at noon; it has nothing to do
with the eﬀect of the atmosphere.
Hewitt CP9 28 E21
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
A pulse of red light and a pulse of blue light 5. Violet light
Hewitt CP9 28 E22
35:07, highSchool, multiple choice, < 1 min,
ﬁxed.
During a lunar eclipse, the moon is not
completedly dark, but is often a deep red in
color.
Why?
1. During the sunset, the Sun transfers some
red light to the moon.
2. High frequencies pass more easily through
the long grazing path through the Earth’s
atmosphere to be refracted ﬁnally onto the
moon.
3. Low frequencies pass more easily through
the long grazing path through the Earth’s
atmosphere to be refracted ﬁnally onto the
moon. Chapter 35, section 8, Huygens’ Principle 214 4. none of these
Huygens Reﬂection Analysis
35:08, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
The ﬁgure below shows Christian Huygens’
analysis of the reﬂection from the surface of a
mirror.
The two arcs are Huygens’ wavelets that
were emitted simultaneously from points A
and B at t = 0 .
Assume: Medium 1 is a vacuum and
Medium 2 has an index of refraction greater
than 1. Part 3 of 3
According to Huygens’ principle, which of the
following would NOT be a property of the
wave front AB after it had propagated from
time t from the position shown in the ﬁgure?
The new (reﬂected) wave front would
1. be tangent to the wavelet centered at A.
2. pass through the point D.
3. form an angle equal to θ with the mirror
surface.
4. form an angle equal to θ with the surface
normal. θ nt
ide nt
inc fro
ve
wa B
A 6. form a right angle with the reﬂected ray.
mirror surface D
The angle of incidence θ is equal to which
angle?
1. θ = B DA
2. θ = B AD
3. θ = ABD
4. none of these
Part 2 of 3
The radius rA of the wavelet centered at A
must be equal to
1. rA = AD
2. rA = AB
3. rA = BD 5. touch the wavelet centered at A at a point
that is exactly distance AB away from point
D. 7. none of these.
Huygens Refraction Analysis
35:08, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
The ﬁgure below shows Christian Huygens’
analysis of the refraction of a wave front AB
upon entering Medium 2 from Medium 1.
The two arcs are Huygens’ wavelets that
were emitted from points A and B at t = 0 .
Assumre: Medium 1 is a vacuum and
Medium 2 has an index of refraction greater
than 1. Chapter 35, section 8, Huygens’ Principle nt y
Ra e
av
W fro 3. sin θ1 =
4. sin θ1 = θ1 5. sin θ1 = B 6. sin θ1 = t
v1
A
D v 2t 7. sin θ1 =
Medium 1
Medium 2 θ2 Ray C According to Huygens, the index of refraction of Medium 2 is equal to the ratio of which
two line segments?
1. n =
2. n =
3. n =
4. n =
5. n =
6. n =
7. n =
8. n = AB
CD
AC
BD
CD
AB
BD
AC
AB
AD
BD
AD
AC
AD
CD
AD AB
AD
BD
2. sin θ1 =
AB 1. n =
2. n = 4. n =
5. n =
6. n =
7. n =
8. n = CD
AD
AC
sin θ2 =
CD sin θ2 = sin θ2 =
sin θ2 =
sin θ2 =
sin θ2 =
sin θ2 =
sin θ2 = AC
AD
AC
AB
AB
AD
BD
AC
BD
AD
BD
AB Part 3 of 3
The conclusion of Huygen’s analysis is that
the index of refraction of Medium 2 is equal
to the ratio of the sines of which two angles? 3. n = Part 2 of 3
The sines of the angles θ1 and θ2 are equal,
respectively to
1. sin θ1 = 8. sin θ1 = BD
AD
BD
CD
CD
AD
AB
CD
AC
AD
AC
CD 215 B AD
ABD
B DA
DAC
ADC
DAC
B DA
B AD
C AD
ADC
B AD
ADC
ABD
ACD
B DA
ADC Chapter 35, section 9, Total Internal Reﬂection
Conceptual 20 27
35:09, highSchool, multiple choice, < 1 min,
ﬁxed.
In many weapons systems, including aircraft, ﬁber optics is used to transmit information.
Why might ﬁber optics be particular useful
in a military application such as a battleﬁeld
environment?
I) Fiber optics are very light.
II) Fiber optics are very compact.
III) Fiber optics are ﬂexible.
IV) Fiber optics can carry more information
than a copper wire. 216 Conceptual 20 Q29
35:09, highSchool, multiple choice, < 1 min,
ﬁxed.
A polar bear actually has translucent colorless fur and black skin.
What are the beneﬁts it derives from this?
1. It acts like a ﬁbre optic cable.
2. It gives the fur white in color.
3. It makes the fur shiny.
4. All of these
5. None of these 1. I only
2. II only Conceptual 20 Q32
35:09, highSchool, multiple choice, < 1 min,
ﬁxed. 3. III only
4. IV only
5. I and II only
6. II and III only If you swim just below the surface of a
pool and look straight up, you will see the
sky. However, if you look at a glancing angle
to the surface of the water, you will see a
reﬂection of the bottom of the pool.
What caused this to happen? 7. I and IV only 1. total internal reﬂection 8. I, II and IV only 2. to reﬂection 9. I, III and IV only 3. refraction 10. All of these 4. None of these Conceptual 20 Q28
35:09, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 27 E05
35:09, highSchool, multiple choice, < 1 min,
ﬁxed. If you left a glass ﬁberoptic cable unshielded by any plastic covering, should the
light still be able to travel through the cable? Why are the interiors of optical instruments
black? 1. Yes
2. No 1. The interior coating absorbs rather than
reﬂects light, and therefore appears black.
2. The interior should be black in order to
keep cool. Chapter 35, section 9, Total Internal Reﬂection 217 3. There is nothing inside optical instruments. Holt SF 15Rev 37
35:09, highSchool, numeric, < 1 min, ﬁxed. 4. In light the interiors look black, but in a
dark environment, they can emit light.
Hewitt CP9 28 R25
35:09, highSchool, numeric, > 1 min, normal. Part 1 of 3
Light with a wavelength of λ = 589 nm
travels from a certain material to air.
a) Calculate the critical angle for zircon
(n = 1.923) when it is surrounded by air. What is the critical angle of light in glass if
the index of refraction of glass is 1.4 and the
index of refraction of air is 1.05? Part 2 of 3
b) Calculate the critical angle for ﬂuorite (n =
1.434) when it is surrounded by air. Holt SF 15C 01
35:09, highSchool, numeric, < 1 min, ﬁxed. Part 3 of 3
c) Calculate the critical angle for ice (n =
1.309) when it is surrounded by air. Find the critical angle for light traveling
from glycerine (n = 1.473) into air.
Holt SF 15C 02
35:09, highSchool, numeric, < 1 min, ﬁxed.
Calculate the critical angle for light traveling from glycerine (n = 1.473) into water
(n = 1.333).
Holt SF 15C 03
35:09, highSchool, numeric, < 1 min, ﬁxed. Holt SF 15Rev 38
35:09, highSchool, numeric, < 1 min, ﬁxed.
Light traveling in air enters the ﬂat side of
a prism made of crown glass (n = 1.52), as
shown in the ﬁgure. 45◦ Find the critical angle for light traveling
from ice (n = 1.309) into air.
Holt SF 15C 04
35:09, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
a) Find the critical angle in air for diamond
(n = 2.419).
Part 2 of 2
b) Find the critical angle in air for cubic
zirconia (n = 2.20).
Holt SF 15Rev 36
35:09, highSchool, numeric, < 1 min, ﬁxed.
Calculate the critical angle for light going
from glycerine (n = 1.473) into air. What is the critical angle?
Holt SF 15Rev 53
35:09, highSchool, numeric, > 1 min, wordingvariable.
A jewel thief decides to hide a stolen diamond by placing it at the bottom of a crystalclear fountain. He places a circular piece of
wood on the surface of the water and anchors
it directly above the diamond at the bottom
of the fountain. Chapter 35, section 9, Total Internal Reﬂection 218
30.0◦ d 60◦
2m
60◦
If the fountain is 2.00 m deep, ﬁnd the
minimum diameter, d of the piece of wood
that would prevent the diamond from being
seen from outside the water.
Holt SF 15Rev 56
35:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A ﬁberoptic cable used for telecommunications has an index of refraction of 1.53.
a) For total internal reﬂection of light inside the cable, what is the minimum angle of
incidence to the inside wall of the cable if the
cable is in air?
Part 2 of 2
b) What is the minimum angle of incidence to
the inside wall of the cable if the cable is in
water? 60◦ a) Trace the path of the light ray through
the glass and ﬁnd the angle of incidence of the
ray at the bottom of the prism.
Part 2 of 2
b) Calculate the critical angle corresponding
to total internal reﬂection.
Holt SF 15Rev 58
35:09, highSchool, numeric, < 1 min, wordingvariable.
Light strikes the surface of a prism, n =
1.80, as shown in the ﬁgure. 45◦ Holt SF 15Rev 57
35:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A ray of light traveling in air strikes the
midpoint of one face of an equiangular glass
prism (n = 1.55) at an angle of exactly 30.0◦ . If the prism is surrounded by a ﬂuid, what is
the maximum index of refraction of the ﬂuid
that will still cause total internal reﬂection
within the prism?
Holt SF 15Rev 59
35:09, highSchool, numeric, < 1 min, wordingvariable.
A ﬁberoptic rod consists of a central strand
of material surrounded by an outer coating.
The interior portion of the rod has an index
of refraction of 1.60. Chapter 35, section 9, Total Internal Reﬂection
If all rays striking the interior walls of the
rod with incident angles greater than 59.5◦
are subject to total internal reﬂection, what
is the index of refraction of the coating?
Holt SF 15Rev 62
35:09, highSchool, numeric, > 1 min, wordingvariable.
A laser beam traveling in air strikes the
midpoint of one end of a slab of material with
index of refraction 1.48 as shown in the ﬁgure
below.
42 cm
◦ 50 3.1 mm Find the number of internal reﬂections of
the laser beam before it ﬁnally emerges from
the opposite end of the slab. 219 Chapter 35, section 10, Fermat’s Principle
Hewitt CP9 28 R04
35:10, highSchool, multiple choice, < 1 min,
ﬁxed.
What does Fermat’s principle say?
1. Light is visible.
2. Nothing in the world can travel with the
speed greater than the speed of light.
3. Light can be reﬂected.
4. Light can be refracted.
5. Out of all possible paths that light might
take to get from one point to another, it takes
the path that requires the shortest time. 220 Chapter 35, section 12, Luminous Intensity
Concept 09 15
35:12, highSchool, multiple choice, < 1 min,
ﬁxed.
The intensity of light from a central source
varies inversely as the square of the distance.
If you lived on a planet only half as far from
the Sun as our Earth, how would the intensity
compare with that on Earth?
1. Two times
2. Three times
3. Four times
4. Eight times
Hewitt CP9 09 R11
35:12, highSchool, multiple choice, < 1 min,
ﬁxed. excites their electrons into a higher energy
level.
3. No; light energy is related to the wavelength of the light, rather than the intensity.
4. No; light intensity gets weaker with distance, but the total amount of light over a
spherical surface is the same at all distances
from the source.
5. More information is needed.
Hewitt CP9 26 E37
35:12, highSchool, multiple choice, < 1 min,
ﬁxed.
The planet Jupiter is more than ﬁve times
as far from the Sun as the Earth.
How does the brightness of the Sun appear
at this greater distance?
1. 5 times the brightness on Earth How does the brightness of light change
when a point source of light is brought twice
as far away? 2. 1/5 of the brightness on Earth
3. 1/25 of the brightness on Earth 1. same
4. 25 times the brightness on Earth
2. double
5. the same as the brightness on Earth
3. four times brighter than before
6. More information is needed.
4. one fourth darker than before
5. The distance is needed.
Hewitt CP9 26 E35
35:12, highSchool, multiple choice, < 1 min,
ﬁxed.
The intensity of light falls oﬀ as the inverse
square of the distance from the source.
Does this mean that light energy is lost?
1. Yes; the energy of light is proportional to
the intensity.
2. Yes; light interacts with air atoms and 221 Chapter 36, section 2, Images Formed by Flat Mirrors 222 Conceptual 20 Q01
36:02, highSchool, multiple choice, > 1 min,
ﬁxed. Hewitt CP9 28 E03
36:02, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 2
How does the smoothness of a mirror aﬀect
the clarity of the image you see?
1. The image becomes clear. Cowboy Joe wishes to shoot his assailant
by ricocheting a bullet oﬀ a mirrored metal
plate.
To do so, should he simply aim at the mirrored image of his assailant? 2. The image becomes blur. 1. No; if he does so, he will miss the target. 3. There is no change in the image.
Part 2 of 2
What is the diﬀerence between a set of parallel
rays reﬂected oﬀ a very smooth mirror and the
same rays reﬂected oﬀ a more bumpy mirror
made of the exact material? 2. Yes; the ricocheting bullet will follow the
same change in direction upon impact that
light follows when reﬂecting from a plane surface.
3. No; light is refracted in metal.
4. No; an image is not a reliable target. 1. smooth; stay parallel; bumpy; can scatter
2. smooth; can scatter; bumpy; stay parallel
3. Both stay parallel
4. Both can scatter
Conceptual 20 Q05
36:02, highSchool, multiple choice, < 1 min,
normal.
As you walk toward a fulllength plane mirror, your image walks towards you.
What is the speed of your image if your
speed is 1 m/s?
1. 1 m/s
2. 4.5 m/s
3. 6 m/s
4. 1.25 m/s
5. None of these Hewitt CP9 28 E11
36:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is it diﬃcult to see the roadway in
front of you when driving on a rainy night?
1. The road is covered with water which acts
like a plane mirror.
2. Lightning may prevent you from seeing
the roadway clearly.
3. There is no moon to light the roadway.
4. It is much darker outside than on a clear
night.
Hewitt CP9 28 E12
36:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What must be the minimum length of a
plane mirror in order for you to see a full view
of yourself?
1. One fourth of your height Chapter 36, section 2, Images Formed by Flat Mirrors
2. Half of your height
3. Twice of your height 223 How tall will the wiped area be compared
with the vertical dimension of your face?
1. The wiped area will be half as tall as your
face. 4. One third of your height
Hewitt CP9 28 E13
36:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What eﬀect does your distance from the
plane mirror that is half your height have?
1. If you are too far away from the mirror,
you cannot see your image.
2. The closer you are to the mirror, the more
you can see of your body.
3. The farther you are from the mirror, the
more you can see of your body.
4. A halfheight mirror works at any distance.
Hewitt CP9 28 E14
36:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Hold a pocket mirror at almost an arm’s
length from your face and note the amount of
your face you can see.
To see more of your face, should you hold
the mirror closer or farther, or would you have
to have a larger mirror? 2. The wiped area will be one fourth as tall
as your face.
3. The wiped area will be one third as tall
as your face.
4. The wiped area will twice as tall as your
face.
4. The wiped area will the same tall as your
face.
Hewitt CP9 28 E16
36:02, highSchool, multiple choice, < 1 min,
ﬁxed.
A diagram shows a person and her twin
at equal distances on opposite sides of a thin
wall. Suppose a window is to be cut in the
wall so each twin can see a complete view of
the other.
Find the size of the smallest window that
can be cut in the wall to do the job.
1. one fourth the height of the person or her
twin
2. one third the height of the person or her
twin
3. half the height of the person or her twin 1. You have to have a larger mirror.
4. twice the height of the person or her twin
2. You can hold the mirror closer.
3. You can hold the mirror farther. 5. the same the height of the person or her
twin Hewitt CP9 28 E15
36:02, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 28 P02
36:02, highSchool, multiple choice, < 1 min,
normal. On a steamy mirror wipe away just enough
to see your full face. A butterﬂy at eye level is 20 cm in front of
a plane mirror. You are behind the butterﬂy, Chapter 36, section 2, Images Formed by Flat Mirrors
50 cm from the mirror.
What is the distance between your eye and
the image of the butterﬂy in the mirror?
Hewitt CP9 28 P03
36:02, highSchool, numeric, < 1 min, normal. 224 4. 5
5. 4
6. 10
7. 12 If you take a photograph of your image in a
plane mirror, how many meters away should
you set your focus if you are 2 m in front of
the mirror?
Hewitt CP9 28 P04
36:02, highSchool, numeric, < 1 min, normal.
Suppose you walk toward a mirror at 2 m/s.
How fast do you and your image approach
each other?
Reﬂections in Mirrors 01
36:02, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: Often it is easier to make a rough
drawing the determine the answer to what
might appear to be a tedious question.
In a clothing store two ﬂat mirrors are
hinged at one edge (for you to view the clothes
you desire to purchase).
You (as indicated by an L shaped object)
are standing in the 47 ◦ wedge formed by two
mirrors. A view from above is shown below. 8. 3
9. 7
Reﬂections in Mirrors 02
36:02, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: Make a rough drawing to check your
answer.
Often in a clothing store two ﬂat mirrors
are hinged at one edge (for you to view the
clothes you desire to purchase).
You (as indicated by an L shaped object)
are standing in the 45 ◦ wedge formed by two
mirrors. A view from above is shown below. 45 ◦ How many images can you see in the hinged
mirrors?
1. 7 47 ◦ 36 ◦ 2. 5
3. 9 How many images can you see in the hinged
mirrors? 34 ◦ 4. 11 1. 6 5. 3 2. 8 6. 4 3. 9 7. 6
8. 8 Chapter 36, section 2, Images Formed by Flat Mirrors
9. 10 225 Chapter 36, section 3, Images Formed by Concave Mirrors 226 and inverted.
Concave mirror image
36:03, highSchool, multiple choice, < 1 min,
ﬁxed.
The goal of this problem is to describe the
image of an object as the object moves towards a concave mirror of radius R from a far
distance. The ﬁgure shows a graph of s vs s,
1
1
1
from the equation + = , for a given rass
f
dius R, where R = 2f . From the graph you
can obtain the answer to the following question.
s'
3f s'=sf/(sf)
R=2 f Holt SF 14B 01
36:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
Consider a concave mirror with a focal
length of 10.00 cm.
a) Find the image distance when the object
distance is 10.00 cm. (Answer with −1000 if
the image does not exist.) (2 f, 2 f) 2f Part 2 of 4
b) Find the image distance when the object
distance is 5.00 cm. (Answer with −1000 if
the image does not exist.) f
concave
mirror 7. s < 0; the image is larger than the object
and erect. f 2f 3f s f
s' s' =s
When the object is at 0 < s < f , then Part 3 of 4
c) Find the magniﬁcation of the image for
part b). (Answer with −1000 if the image
does not exist.)
Part 4 of 4
d) Describe the image for part b). 1. None of these
1. real, inverted, larger
2. s < 0; the image is larger than the object
and inverted. 2. virtual, inverted, larger
3. real, upright, larger 3. s < 0; the image is smaller than the object and erect. 4. virtual, upright, larger
5. real, inverted, smaller 4. s < 0; the image is smaller than the object and inverted. 6. virtual, inverted, smaller
7. real, upright, smaller 5. s > 0; the image is larger than the object
and erect. 8. virtual, upright, smaller
9. None of these 6. s > 0; the image is larger than the object Chapter 36, section 3, Images Formed by Concave Mirrors 227 Holt SF 14B 02
36:03, highSchool, numeric, > 1 min, normal. Part 2 of 3
b) Calculate the magniﬁcation of the image. Part 1 of 3
A concave shaving mirror has a focal length
of 33 cm.
a) Calculate the image position of a cologne
bottle placed in front of the mirror at a distance of 93 cm. (Answer with −1000 if the
image does not exist.) Part 3 of 3
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger Part 2 of 3
b) Calculate the magniﬁcation of the image.
(Answer with −1000 if the image does not
exist.)
Part 3 of 3
c) Describe the image. 4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller 1. real, inverted, larger
8. virtual, upright, smaller
2. virtual, inverted, larger
9. None of these
3. real, upright, larger
4. virtual, upright, larger Holt SF 14B 04
36:03, highSchool, numeric, > 1 min, wordingvariable. 5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller Part 1 of 5
A pen placed 11.0 cm from a concave spherical mirror produces a real image 13.2 cm from
the mirror.
a) What is the focal length of the mirror? 8. virtual, upright, smaller
9. None of these
Holt SF 14B 03
36:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A concave makeup mirror is designed so
that a person 25.0 cm in front of it sees an
upright image at a distance of 50.0 cm behind
the mirror.
a) What is the radius of curvature of the
mirror? Part 2 of 5
b) Calculate the magniﬁcation of the image.
Part 3 of 5
Assume the pen is placed 27.0 cm from the
mirror.
c) What is the position of the new image?
(Answer with −1000 if the image does not
exist.)
Part 4 of 5
d) What is magniﬁcation of the new image?
(Answer with −1000 if the image does not
exist.) Chapter 36, section 3, Images Formed by Concave Mirrors
Part 5 of 5
e) Describe the new image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller 228 8. virtual, upright, smaller
9. None of these
Part 3 of 6
c) Find the magniﬁcation of the image when
an upright pencil is placed 25.0 cm from the
mirror. (Answer with −1000 if the image does
not exist.)
Part 4 of 6
d) Describe the image.
1. real, inverted, larger 7. real, upright, smaller
8. virtual, upright, smaller 2. virtual, inverted, larger
3. real, upright, larger 9. None of these
4. virtual, upright, larger
Holt SF 14Rev 34
36:03, highSchool, numeric, > 1 min, wordingvariable. 5. real, inverted, smaller
6. virtual, inverted, smaller Part 1 of 6
A concave shaving mirror has a radius of
curvature of 25.0 cm.
a) Find the magniﬁcation of the image
when an upright pencil is placed 45.0 cm from
the mirror. (Answer with −1000 if the image
does not exist.)
Part 2 of 6
b) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger 7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Part 5 of 6
e) Find the magniﬁcation of the image when
an upright pencil is placed 5.00 cm from the
mirror. (Answer with −1000 if the image does
not exist.)
Part 6 of 6
f) Describe the image. 3. real, upright, larger
4. virtual, upright, larger 1. real, inverted, larger
2. virtual, inverted, larger 5. real, inverted, smaller
6. virtual, inverted, smaller 3. real, upright, larger
4. virtual, upright, larger 7. real, upright, smaller Chapter 36, section 3, Images Formed by Concave Mirrors
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Holt SF 14Rev 35
36:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A concave spherical mirror can be used to
project an image onto a sheet of paper, allowing the magniﬁed image of an illuminated real
object to be accurately traced.
a) If you have a concave mirror with a focal
length of 8.5 cm, where would you place a
sheet of paper so that the image projected
onto it is twice as far from the mirror as the
object is? 229 Holt SF 14Rev 49
36:03, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A glowing electric light bulb placed 15 cm
from a concave spherical mirror produces a
real image 8.5 cm from the mirror. The light
bulb is moved to a position 25 cm from the
mirror.
a) What is the image position? (Answer
with −1000 if the image does not exist.)
Part 2 of 4
b) Find the magniﬁcation of the ﬁrst image.
Part 3 of 4
c) Find the magniﬁcation of the ﬁnal image.
(Answer with −1000 if the image does not
exist.)
Part 4 of 4
d) Describe the two images.
1. real, inverted, larger Part 2 of 3
b) What is the magniﬁcation of the image?
Part 3 of 3
c) Describe the image. 2. virtual, inverted, larger
3. real, upright, larger
4. virtual, upright, larger 1. real, upright, larger
5. real, inverted, smaller
2. real, inverted, larger
6. virtual, inverted, smaller
3. virtual, upright, larger
7. real, upright, smaller
4. virtual, inverted, larger
8. virtual, upright, smaller
5. real, upright, smaller
9. None of these
6. real, inverted, smaller
7. virtual, upright, smaller Holt SF 14Rev 52
36:03, highSchool, numeric, > 1 min, wordingvariable. 8. virtual, inverted, smaller
9. None of these Part 1 of 3
An object is placed 10.0 cm in front of a
mirror and an image of the object is formed Chapter 36, section 3, Images Formed by Concave Mirrors
on a wall 2.00 m away from the mirror.
a) What is the radius of curvature of the
mirror? 230 6. p = −2q
7. q = 2p Part 2 of 3
b) Find the magniﬁcation of the image.
Part 3 of 3
c) Describe the image.
1. real, upright, larger 8. q = −2p
9. None of these.
Holt SF 14Rev 57
36:03, highSchool, numeric, > 1 min, wordingvariable. 2. real, inverted, larger
3. virtual, upright, larger
4. virtual, inverted, larger Part 1 of 2
An object 2.70 cm tall is placed 12.0 cm
in front of a mirror, which creates an upright
image that is 5.40 cm in height.
a) What is the magniﬁcation of the image? 5. real, upright, smaller
6. real, inverted, smaller Part 2 of 2
b) What is the radius of curvature of the
mirror? 7. virtual, upright, smaller
8. virtual, inverted, smaller Holt SF 14Rev 58
36:03, highSchool, multiple choice, > 1 min,
ﬁxed. 9. None of these
Holt SF 14Rev 54
36:03, highSchool, numeric, > 1 min, ﬁxed.
A ﬂat mirror can be treated as a special
type of spherical mirror that has an “inﬁnite”
radius of curvature.
If the equation
2
11
=+
R
pq
is applied to a ﬂat mirror, which is the correct
relationship between p and q ?
1. p = 0, q = ∞
2. p = ∞, q = 0 A “ﬂoating coin” illusion consists of two
parabolic mirrors, each with a focal length of
7.5 cm, facing each other so that their centers
are 7.5 cm apart (See the following ﬁgure).
Small hole
Parabolic
mirrors
Coins
Place a few coins on the lower mirror. An
image of the coins forms due to the mirror
system. Determine which of the following
statements is true. 4. p = −q 1. The virtual and inverted image is located
right on the lower mirror with the magniﬁcation of −1. 5. p = 2q 2. The real and upright image is located 3. p = q Chapter 36, section 3, Images Formed by Concave Mirrors
right in the top mirror opening with the magniﬁcation of +1.
3. The real and inverted image is located 7.5
cm on top of the top mirror opening with the
magniﬁcation of −1.
4. The virtual and inverted image is located
7.5 cm on top of the top mirror opening with
the magniﬁcation of −2.
5. The virtual and upright image is located
7.5 cm on top of the top mirror opening with
the magniﬁcation of 1.
6. The real and upright image is located 7.5
cm on top of the top mirror opening with the
magniﬁcation of 2.
7. The real and inverted image is located 7.5
cm below the lower mirror with the magniﬁcation of −1.
8. The virtual and upright image is located
7.5 cm below the lower mirror with the magniﬁcation of 1. 231 Chapter 36, section 4, Images Formed by Convex Mirrors 232 3. II and IV only
Conceptual 20 Q21
36:04, highSchool, multiple choice, < 1 min,
ﬁxed. 4. I and IV only
5. II and III only Part 1 of 2
What shape are the security mirrors often
placed high in the corners of stores?
1. Bowed outward 6. All of these
Holt SF 14C 01
36:04, highSchool, numeric, > 1 min, wordingvariable. 2. Bowed inward
3. ﬂat
Part 2 of 2
Why are the security mirrors shaped that
way?
I) to capture a wide ﬁeld of view as possible
II) to focus the cash register
III) to focus the people Part 1 of 4
The image of a crayon appears to be 23.0
cm behind the surface of a convex mirror and
is 1.70 cm tall. The mirror’s focal length is
46.0 cm.
a) How far in front of the mirror is the
crayon positioned?
Part 2 of 4
b) Calculate the magniﬁcation of the image. 1. I only
2. II only Part 3 of 4
c) Describe the image. 3. III only 1. real, inverted, larger 4. All of these 2. virtual, inverted, larger Conceptual 20 Q22
36:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Some of the mirrors you might see in an
amusement park make some parts of you seem
large, while at the same time making other
parts seem smaller.
How is this accomplished?
I)
II)
III)
IV) The mirrors are curved outward
The mirrors are curved inward
The mirrors are ﬂat
The mirrors are distorted 1. I and II only
2. I and III only 3. real, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Part 4 of 4
d) How tall is the actual crayon?
Holt SF 14C 02
36:04, highSchool, numeric, > 1 min, wording Chapter 36, section 4, Images Formed by Convex Mirrors 233 variable.
Part 1 of 4
A convex mirror with a focal length of 0.26
m forms a 0.081 m tall image of an automobile
at a distance of 0.25 m behind the mirror.
a) How far from the mirror is the car located? Part 3 of 4
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger Part 2 of 4
b) What is the magniﬁcation of the image?
Part 3 of 4
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger 4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these 4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Part 4 of 4
d) What is the height of the car?
Holt SF 14C 03
36:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A convex mirror of focal length 33 cm forms
an image of a soda bottle at a distance of 19
cm behind the mirror. The height of the
image is 7.0 cm.
a) Where is the object located? Part 4 of 4
d) How tall is the object?
Holt SF 14C 04
36:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A convex mirror with a radius of curvature
of 0.550 m is placed above the aisles in a store.
a) Determine the image distance of a customer lying on the ﬂoor 3.1 m directly below
the mirror.
Part 2 of 3
b) What is the magniﬁcation of the image?
Part 3 of 3
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger Part 2 of 4
b) What is the magniﬁcation of the image? 4. virtual, upright, larger Chapter 36, section 4, Images Formed by Convex Mirrors
5. real, inverted, smaller
6. virtual, inverted, smaller 234 Part 1 of 3
A candle is 49 cm in front of a convex
spherical mirror that has a focal length of 35
cm.
a) What is the image distance? 7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Holt SF 14C 05
36:04, highSchool, numeric, > 1 min, wordingvariable. Part 2 of 3
b) Calculate the magniﬁcation of the image.
Part 3 of 3
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger Part 1 of 3
A spherical glass ornament is 6.00 cm in
diameter. An object is placed 10.5 cm away
from the ornament.
a) Where will its image form? 3. real, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller Part 2 of 3
b) What is the magniﬁcation of the image?
Part 3 of 3
c) Describe the image. 6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller 1. real, inverted, larger
9. None of these
2. virtual, inverted, larger
3. real, upright, larger Holt SF 14Rev 36
36:04, highSchool, numeric, > 1 min, wordingvariable. 4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller Part 1 of 4
A convex mirror with a radius of curvature
of 45.0 cm forms a 1.70 cm tall image of a
pencil at a distance of 15.8 cm behind the
mirror.
a) Find the object distance for the pencil.
Part 2 of 4
b) Find the magniﬁcation of the image. 9. None of these
Holt SF 14C 06
36:04, highSchool, numeric, > 1 min, wordingvariable. Part 3 of 4
c) Describe the image.
1. real, inverted, larger Chapter 36, section 4, Images Formed by Convex Mirrors 235 2. virtual, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger
3. real, upright, larger
4. virtual, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller
5. real, inverted, smaller
6. virtual, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
7. real, upright, smaller
8. virtual, upright, smaller
8. virtual, upright, smaller
9. None of these
9. None of these
Part 4 of 4
d) What is the height of the object?
Holt SF 14Rev 48
36:04, highSchool, numeric, > 1 min, wordingvariable.
A child holds a candy bar 15.5 cm in front of
the convex sideview mirror of an automobile.
The image height is reduced by one half.
What is the radius of curvature of the mirror?
Holt SF 14Rev 50
36:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A convex mirror is placed on the ceiling at
the intersection of two hallways. If a young
man stands directly underneath the mirror,
his shoe, which is a distance of 195 cm from
the mirror, forms an image that appears 12.8
cm behind the mirror’s surface.
a) What is the mirror’s focal length?
Part 2 of 3
b) What is the magniﬁcation of the image?
Part 3 of 3
c) Describe the image.
1. real, inverted, larger Holt SF 14Rev 51
36:04, highSchool, numeric, < 1 min, wordingvariable.
The sideview mirror of an automobile has
a radius of curvature of 11.3 cm. The mirror
produces a virtual image one third the size of
the object.
How far is the object from the mirror?
Holt SF 14Rev 55
36:04, highSchool, numeric, < 1 min, wordingvariable.
A real object is placed at the zero end of
a meter stick. A large concave mirror at the
100.0 cm end of the meterstick forms an image
of the object at the 70.0 cm position. A small
convex mirror placed at the 20.0 cm position
forms a ﬁnal image at the 10.00 cm point.
What is the radius of curvature of the convex mirror?
Holt SF 14Rev 56
36:04, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
A dedicated sportscar enthusiast polishes
the inside and outside surfaces of a hubcap
that is a section of a sphere. When he looks
into one side of the hubcap, he sees an image Chapter 36, section 4, Images Formed by Convex Mirrors
of his face 30.0 cm behind the hubcap. He
then turns the hubcap over and sees another
image of his face 10.0 cm behind the hubcap.
a) How far is his face from the hubcap?
Part 2 of 4
b) What is the radius of curvature of the
hubcap?
Part 3 of 4
c) What is the magniﬁcation for the ﬁrst image?
Part 4 of 4
d) What is the magniﬁcation for the second
image?
Holt SF 14Rev 59
36:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Use the mirror equation and the equation
for magniﬁcation to determine which of the
following statements is true for the image of a
real object formed by a convex mirror.
1. always upright, real, larger than the object. 236 object.
9. None of these
Part 2 of 2
Use the mirror equation and the equation
for magniﬁcation to determine which of the
following statements is true for the image of
a real object formed by any spherical mirror
with p < f .
1. always upright, real.
2. always inverted, real.
3. always upright, virtual.
4. always inverted, virtual.
5. None of these
Mirrors
36:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
Consider a concave mirror with radius R.
An upright object is placed
in between the interval R/2 and R. 2. always inverted, real, larger than the object.
R R/2 3. always upright, virtual, larger than the
object.
The image is
4. always inverted, virtual, larger than the
object.
5. always upright, real, smaller than the
object. 1. real, inverted, enlarged.
2. real, inverted, reduced.
3. real, upright, enlarged. 6. always inverted, real, smaller than the
object.
7. always upright, virtual, smaller than the
object. 4. real, upright, reduced.
5. virtual, inverted, enlarged.
6. virtual, inverted, reduced. 8. always inverted, virtual, smaller than the Chapter 36, section 4, Images Formed by Convex Mirrors
7. virtual, upright, enlarged.
8. virtual, upright, reduced.
9. real, upright, same size.
10. virtual, upright, same size.
Part 2 of 3
Hint: A sketch may help you answer the
questions.
Consider a new situation for the following
two questions.
The light rays from an upright object, when
reﬂected by a spherical mirror, form a virtual
image.
The absolute value of the magniﬁcation of
this image is less than one.
1. The mirror can only be concave.
2. The mirror can only be convex.
3. The mirror can either be concave or convex.
Part 3 of 3
Consider a same situation in the previous
question, that is
The light rays from an upright object, when
reﬂected by a spherical mirror, form a virtual
image.
The absolute value of the magniﬁcation of
this image is less than one.
1. The virtual image is upright and behind
the mirror.
2. The virtual image is inverted and behind
the mirror.
3. The virtual image is upright and in front
of the mirror.
4. The virtual image is inverted and in front
of the mirror. 237 Chapter 36, section 5, Spherical Mirrors: Ray Tracing
Mirror Convergent Diagram
36:05, highSchool, multiple choice, > 1 min,
wordingvariable. 238 2.
f Hint: The convergent mirror in this problem is a part of a lens/mirror system so the
object in this problem may be either real or
virtual. Construct a ray diagram.
Given: A virtual object is located to the
right of a convergent mirror. The object’s
distance from the mirror and its focal length
are shown in the ﬁgure below. 0 19 19
f
f
31 12 19
f0
31 19
f
12 3.
f f 19
f
12
Which diagram correctly shows the image?
0 4.
f
1.
f 0
19
f0
31 19
f
12 19 19
f
f
31 12 Mirror Divergent Diagram
36:05, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: The convergent mirror in this problem is a part of a lens/mirror system so the
object in this problem may be either real or
virtual. Construct a ray diagram.
Given: A virtual object is located to the
right of a divergent mirror. The object’s distance from the mirror and its focal length are Chapter 36, section 5, Spherical Mirrors: Ray Tracing 239 shown in the ﬁgure below. 3.
f
f 19 −19
f
f
12
7 0 19
f
12
Which diagram correctly shows the image?
0 4.
f
1.
f −19
f
7
19 −19
f
f
12
7 0 f Spherical Mirror A 01
36:05, highSchool, numeric, > 1 min, wordingvariable. h q
0 19
f
12 Part 1 of 2
A concave spherical mirror has a radius of
curvature of 30.2 cm . The object distance is
27.4 cm . 2. −19
f
7 0 19
f
12 Rp f h Scale: 10 cm =
Find the magnitude of the image distance.
Part 2 of 2
Find the magniﬁcation. Chapter 36, section 5, Spherical Mirrors: Ray Tracing
Spherical Mirror A 02
36:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A convex spherical mirror has a radius of
curvature of 30.6 cm . The object distance is
14 cm . 240 Part 2 of 2
Find the magniﬁcation.
Spherical Mirror B 01
36:05, highSchool, numeric, > 1 min, wordingvariable.
A concave spherical mirror forms a real
image 2.36 times the size of the object. The
object distance is 21.5 cm . h
q h
p q f h
p R R f h Scale: 10 cm = Scale: 10 cm =
Find the magnitude of the image distance.
Part 2 of 2
Find the magniﬁcation.
Spherical Mirror A 03
36:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A concave spherical mirror has a radius of
curvature of 30.6 cm . The object distance is
4.8 cm . Find the magnitude of the radius of curvature of the mirror.
Spherical Mirror B 02
36:05, highSchool, numeric, > 1 min, wordingvariable.
A convex spherical mirror forms a virtual
image 0.52 times the size of the object. The
object distance is 13.7 cm . h
h
R f h h
q p
p f R q Scale: 10 cm =
Scale: 10 cm =
Find the magnitude of the image distance. Find the magnitude of the radius of curvature of the mirror.
Spherical Mirror B 03 Chapter 36, section 5, Spherical Mirrors: Ray Tracing
36:05, highSchool, numeric, > 1 min, wordingvariable. image 1.91 times the size of the object. The
distance between object and image is 28.2 cm . A concave spherical mirror forms a virtual
image 1.46 times the size of the object. The
object distance is 4.8 cm . h
h
R p f f p q h h
R 241 q
Scale: 10 m =
Find the magnitude of the radius of curvature of the mirror. Scale: 10 cm =
Find the magnitude of the radius of curvature of the mirror.
Spherical Mirror C 02
36:05, highSchool, numeric, > 1 min, wordingvariable.
A convex spherical mirror forms a virtual
image 0.52 times the size of the object. The
distance between object and image is 21 cm . h
h
q p f R Scale: 10 cm =
Find the magnitude of the radius of curvature of the mirror.
Spherical Mirror C 03
36:05, highSchool, numeric, > 1 min, wordingvariable.
A concave spherical mirror forms a virtual Chapter 36, section 8, Images Formed by Thin Lenses
Conceptual 20 Q23
36:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Compare a lens used to capture an image
to the lens used to project that image back
onto a screen for viewing.
1. Diﬀerent types
2. Same types
Conceptual 20 Q25
36:08, highSchool, multiple choice, < 1 min,
ﬁxed. 242 36:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
An object is placed 20.0 cm in front of a
converging lens of focal length 10.0 cm.
a) Find the image distance.
Part 2 of 3
b) Find the magniﬁcation.
Part 3 of 3
c) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger Why is the image projected onto the back
of the retina in your eyes upside down? 3. real, upright, larger 1. The eye is a converging lens. 4. virtual, upright, larger 2. The focal length of the eye is very long. 5. real, inverted, smaller 3. The eye is a diverging lens. 6. virtual, inverted, smaller 4. None of these 7. real, upright, smaller Hewitt CP9 01 P06
36:08, highSchool, multiple choice, < 1 min,
ﬁxed.
Poke a hole in a piece of cardboard and hold
the cardboard in the sunlight. Note the image
of the sun that is cast below.
Try a square hole; what is the image of the
sun?
1. triangular 8. virtual, upright, smaller
9. None of these
Holt SF 15B 03
36:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
An object is placed 20.0 cm in front of a
diverging lens of focal length 10.0 cm.
a) Find the image distance. 2. round
Part 2 of 3
b) Find the magniﬁcation. 3. square
4. pentagon Part 3 of 3
c) Describe the image. 5. hexagon
Holt SF 15B 01 1. real, inverted, larger Chapter 36, section 8, Images Formed by Thin Lenses
2. virtual, inverted, larger
3. real, upright, larger
4. virtual, upright, larger 243 0.50.
g) Find the image distance if the object
distance is 5.0 cm.
Part 8 of 8
h) Find the focal length. 5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Holt SF 15B 04
36:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 8
Consider a converging lens with focal length
6.0 cm.
a) Find the object distance if the image
distance is −3.0 cm.
Part 2 of 8
b) Find the magniﬁcation.
Part 3 of 8
Consider a converging lens with focal length
2.9 cm.
c) Find the object distance if the image
distance is 7.0 cm. Holt SF 15Rev 24
36:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 6
An object is placed in front of a diverging
lens with a focal length of 20.0 cm.
a) Find the image distance for an object
distance of 40.0 cm.
Part 2 of 6
b) Find the magniﬁcation.
Part 3 of 6
c) Find the image distance for an object distance of 20.0 cm.
Part 4 of 6
d) Find the magniﬁcation.
Part 5 of 6
e) Find the image distance for an object distance of 10.0 cm.
Part 6 of 6
f) Find the magniﬁcation. Part 4 of 8
d) Find the magniﬁcation. Holt SF 15Rev 25
36:08, highSchool, numeric, < 1 min, wordingvariable. Part 5 of 8
Consider a diverging lens of focal length 6.0
cm.
e) Find the image distance if the object
distance is 4.0 cm. Part 1 of 2
A person looks at a gem using a converging
lens with a focal length of 12.5 cm. The lens
forms a virtual image 30.0 cm from the lens.
a) Find the magniﬁcation. Part 6 of 8
f) Find the magniﬁcation. Part 2 of 2
b) Describe the image. Part 7 of 8
Consider a diverging lens of magniﬁcation 1. real, inverted, smaller Chapter 36, section 8, Images Formed by Thin Lenses
2. real, upright, smaller 244 Where must an object be placed to have a
magniﬁcation of 2.00 in front of a converging
lens of focal length 12.0 cm? 3. virtual, upright, smaller
4. virtual, inverted, smaller Holt SF 15Rev 46
36:08, highSchool, numeric, < 1 min, wordingvariable. 5. real, inverted, larger
6. real, upright, larger
7. virtual, upright, larger A diverging lens is used to form a virtual
image of an object. The object is 80.0 cm in
front of the lens, and the image is 40.0 cm in
front of the lens.
Find the focal length of the lens. 8. virtual, inverted, larger
Holt SF 15Rev 26
36:08, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 4
An object is placed in front of a converging
lens with a focal length of 20.00 cm.
a) Find the image distance for an object
distance of 40.00 cm.
Part 2 of 4
b) Find the magniﬁcation.
Part 3 of 4
c) Find the image distance for an object distance of 10.00 cm.
Part 4 of 4
d) Find the magniﬁcation.
Holt SF 15Rev 44
36:08, highSchool, numeric, < 1 min, wordingvariable.
The image of one kind of United States
postage stamp is 1.50 times the size of the
actual stamp in front of a lens.
Find the focal length of the lens if the distance from the lens to the stamp is 2.84 cm.
Holt SF 15Rev 45
36:08, highSchool, numeric, < 1 min, wordingvariable. Holt SF 15Rev 47
36:08, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A microscope slide is placed in front of a
converging lens with a focal length of 2.44 cm.
The lens forms an image of the slide 12.9 cm
from the lens.
a) How far is the lens from the slide if the
image is real?
Part 2 of 2
b) How far is the lens from the slide if the
image is virtual?
Holt SF 15Rev 48
36:08, highSchool, numeric, < 1 min, wordingvariable.
Part 1 of 2
a) Where must an object be placed to form
an image 30.0 cm from a diverging lens with
a focal length of 40.0 cm?
Part 2 of 2
b) Find the magniﬁcation of the image.
Holt SF 15Rev 55
36:08, highSchool, numeric, < 1 min, wordingvariable.
An object’s distance from a converging lens
is 10.0 times the focal length.
How far is the image from the lens? Express Chapter 36, section 8, Images Formed by Thin Lenses 245 the answer in terms of the focal length.
4. virtual, erect, and larger.
Holt SF 15Rev 63
36:08, highSchool, numeric, > 1 min, wordingvariable. 5. virtual, inverted, and larger.
6. real, erect, and smaller. Part 1 of 2
A nature photographer is using a camera
that has a lens with a focal length of 4.80
cm. The photographer is taking pictures of
ancient trees in a forest and wants the lens to
be focused on a very old tree that is 10.0 m
away.
a) How far must the lens be from the ﬁlm
in order for the resulting picture to be clearly
focused? 7. virtual, erect, and smaller.
8. virtual, inverted, and smaller.
Part 2 of 3
The image distance q to the right of the lens
is
1. q = Part 2 of 2
b) How much would the lens have to be moved
to take a picture of another tree that is only
1.75 m away? 2. q = Single Lens 01
36:08, highSchool, multiple choice, > 1 min,
wordingvariable. 4. q = Part 1 of 3
Hint: You may wish to construct a ray
diagram.
11
Given: A real object is located at “ p =
f”
6
to the left of a convergent lens with a focal
length f as shown in the ﬁgure below. 6. q = 3. q = 5. q = 7. q =
8. q =
9. q =
10. q = f f 11
f.
5
13
f.
5
5
f.
2
15
f.
7
11
f.
6
8
f.
3
13
f.
6
7
f.
3
15
f.
8
15
f.
4 Part 3 of 3
Using this lens, the magniﬁcation is
11
6
The image is (× f ) 0 1. real, inverted, and larger.
2. real, inverted, and smaller.
3. real, erect, and larger. 6
1. M = − .
5
5
2. M = − .
2
5
3. M = − .
3
7
4. M = − .
8 Chapter 36, section 8, Images Formed by Thin Lenses
7
5. M = − .
5
6
6. M = − .
7
7
7. M = − .
4
5
8. M = − .
6
8
9. M = − .
7
8
10. M = − .
5 13
f.
4
11
f.
9. q =
4
13
10. q =
f.
7
8. q = Single Lens 03
36:08, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: Construct a ray diagram. 11
f”
Given: A real object is located at “ p =
6
to the left of a convergent lens with a focal
length f as shown in the ﬁgure below. f f 11
0
6
The image distance q to the right of the lens (× f )
is 1. q =
2. q =
3. q =
4. q =
5. q =
6. q =
7. q = 11
f.
5
11
f.
6
5
f.
2
13
f.
6
8
f.
3
7
f.
3
7
f.
2 246 Chapter 36, section 9, Combinations of Lenses and Mirrors
f1 =
5m Double Lenses all versions
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5.2 m . Another concave
lens is placed 5.53 m behind the ﬁrst lens with
a focal length −9.7 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer.
f2 =
f1 =
5. 2 m − 9. 7 m
f1f2 f1 f2 p1
10 m
0 5 15 f2 =
6.3 m f1 f2 f2 p1
10 m
0 5 20 m
10 15 20 25 30 35 40 45 At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens? 5.53 m
10 f1 247 20 25 At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens?
Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object?
Double Lenses version 1
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another convex
lens is placed 20 m behind the ﬁrst lens with
a focal length 6.3 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer. Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object?
Double Lenses version 2
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another convex
lens is placed 4 m behind the ﬁrst lens with a
focal length 7.3 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer.
f1 =
f2 =
5m
7.3 m f1 f2 f1 f2 p1
10 m
0 5 4m
10 15 20 Chapter 36, section 9, Combinations of Lenses and Mirrors
At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens?
Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object?
Double Lenses version 3
36:09, highSchool, numeric, > 1 min, wordingvariable. when compared to the initial object?
Double Lenses version 4
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another concave
lens is placed 5 m behind the ﬁrst lens with a
focal length −8.6 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer.
f1 = f2 =
5 m −8.6 m
f1 f2 Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another convex
lens is placed 15 m behind the ﬁrst lens with
a focal length 12 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer.
f1 =
f2 =
5m
12 m f1
p1 0 5 15 f2 p1
10 m
0 5 5m
10 15 20 25 At what distance is the ﬁrst image from the
ﬁrst lens? Part 3 of 4
At what distance is the second image from the
second lens? 15 m
10 f1 Part 2 of 4
What isfthe magniﬁcation of the ﬁrst image?
2 f2 f1 10 m 248 20 25 At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens?
Part 4 of 4
What is the magniﬁcation of the ﬁnal image, Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object?
Double Lenses version 5
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another concave
lens is placed 18 m behind the ﬁrst lens with
a focal length −12 m (see the ﬁgure below). Chapter 36, section 9, Combinations of Lenses and Mirrors
Note: Make a ray diagram sketch in order
to check your numerical answer.
f1 =
f2 =
−12 m
5m
f1 f1 =
5m f1
p1 f1 2
f p1 0 5 18 m
10 15 20 0
25 At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens?
Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object?
Double Lenses version 6
36:09, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
An object is placed 10 m before a convex
lens with focal length 5 m . Another concave
lens is placed 5 m behind the ﬁrst lens with a
focal length −3.4 m (see the ﬁgure below).
Note: Make a ray diagram sketch in order
to check your numerical answer. f2 =
−3.4 m
f2 f1 f2 f2
10 m 10 m 249 5 5m
10 15 20 At what distance is the ﬁrst image from the
ﬁrst lens?
Part 2 of 4
What is the magniﬁcation of the ﬁrst image?
Part 3 of 4
At what distance is the second image from the
second lens?
Part 4 of 4
What is the magniﬁcation of the ﬁnal image,
when compared to the initial object? Chapter 36, section 10, Thin Lenses: Ray Tracing
Lens A 01
36:10, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A convergent lens has a focal length of
6.7 cm . The object distance is 10.8 cm . h
p 250 Part 2 of 2
Find the magniﬁcation.
Lens A 03
36:10, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A convergent lens has a focal length of
20.3 cm . The object distance is 9.7 cm . q
f f h
h h
fq p f Scale: 10 cm =
Find the distance of the image from the
center of the lens. Scale: 10 cm = Part 2 of 2
Find the magniﬁcation. Find the distance of the image from the
center of the lens. Lens A 02
36:10, highSchool, numeric, > 1 min, wordingvariable. Part 2 of 2
Find the magniﬁcation. Part 1 of 2
A divergent lens has a focal length of 20 cm .
The object distance is 18.2 cm . Lens B 01
36:10, highSchool, numeric, > 1 min, wordingvariable.
A convergent lens forms a real image 1.64
times the size of the object. The object distance is 10.8 cm . h
h
fp q f h
p q
f f
h Scale: 10 cm =
Find the distance of the image from the
center of the lens. Scale: 10 cm =
Find the distance of the focal point from Chapter 36, section 10, Thin Lenses: Ray Tracing 251 the center of the lens. variable. Lens B 02
36:10, highSchool, numeric, > 1 min, wordingvariable. A convergent lens forms a real image 1.64
times the size of the object. The distance
between object and image is 28.4 cm . A divergent lens forms a virtual image 0.52
times the size of the object. The object distance is 18.7 cm . h q p f f h h
h fp q f
Scale: 10 cm =
Find the distance of the focal point from
the center of the lens. Scale: 10 cm =
Find the distance of the focal point from
the center of the lens. Lens C 02
36:10, highSchool, numeric, > 1 min, wordingvariable. Lens B 03
36:10, highSchool, numeric, > 1 min, wordingvariable. A divergent lens forms a virtual image 0.52
times the size of the object. The distance
between object and image is 27.7 cm . A convergent lens forms a virtual image
1.92 times the size of the object. The object
distance is 9.6 cm . h
h
fp q f h
h
fq p f
Scale: 10 cm =
Find the distance of the focal point from
the center of the lens. Scale: 10 cm =
Find the distance of the focal point from
the center of the lens. Lens C 03
36:10, highSchool, numeric, > 1 min, wordingvariable. Lens C 01
36:10, highSchool, numeric, > 1 min, wording A convergent lens forms a virtual image
1.92 times the size of the object. The distance Chapter 36, section 10, Thin Lenses: Ray Tracing 252 between object and image is 8.8 cm . 1.
f h f h
fq p f
19
f
12 19
f
7 0 Scale: 10 cm =
Find the distance of the focal point from
the center of the lens.
2.
Lens Convergent Diagram
36:10, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: The convergent lens in this problem
is a part of a lens system so the object in
this problem may be either real or virtual.
Construct a ray diagram.
Given: A real object is located to the left
of a divergent lens. The object’s distance and
image’s distance from the lens and the lens’
focal length are shown in the ﬁgures below. f 19
f
7 19
f
12 f 0 3.
f f f f
19
f
12 19
f
0
12
Which diagram correctly shows the image? 0 19
f
7 Chapter 36, section 10, Thin Lenses: Ray Tracing 253 1. 4.
f 19
f
7 f 19
f
12 f f 19 19
f
f0
12 31 0 Lens Divergent Diagram
36:10, highSchool, multiple choice, > 1 min,
wordingvariable.
Hint: The convergent lens in this problem
is a part of a lens system so the object in
this problem may be either real or virtual.
Construct a ray diagram.
Given: A real object is located to the left
of a divergent lens. The object’s distance and
image’s distance from the lens and the lens’
focal length are shown in the ﬁgures below. f f 19
f
0
12
Which diagram correctly shows the image? 2.
f 19
f
12 f 0 19
f
31 3.
f 19 19
f
f0
12 31 f Chapter 36, section 10, Thin Lenses: Ray Tracing 4.
f 19
f
12 f 0 19
f
31 254 Chapter 36, section 11, Lensmaker’s Equation 255 tive.
Lens Maker Formula 02
36:11, highSchool, numeric, > 1 min, wordingvariable. 5. nonfocusing since the focal length is
zero. The crosssection of a glass lens with an
index of refraction “1.33”, is shown below. 6. nonfocusing since the focal length is inﬁnite. 0.9 cm
0.7 cm Hint: Include both the magnitude and sign,
which indicates whether this is a divergent or
convergent lens.
Determine the focal length f using the
small angle approximation.
Lens Maker Formula 03
36:11, highSchool, multiple choice, > 1 min,
wordingvariable.
The crosssection of a glass lens with an
index of refraction “1.33”, is shown below. Lens Maker Formula 04
36:11, highSchool, multiple choice, < 1 min,
wordingvariable.
Part 1 of 2
A thin composite lens is shown in the ﬁgure,
1
where R1  = R , R2  = R , and n2 > n1 .
2
Hint: In considering the choice, one may
set n2 = n and n1 = 1. R1 R2
n1 The lens has focal length
1. f =
2. f = 0.9 cm
0.7 cm 3. f =
4. f =
5. f = This lens is
1. divergent since the focal length is negative.
2. convergent since the focal length is positive.
3. divergent since the focal length is positive.
4. convergent since the focal length is nega n2 6. f =
7. f =
8. f =
9. f =
10. f = n1
R.
n1 − n 2
2 n1
R.
n2 − n 1
2 n1
R.
n1 − n 2
n1
R.
n2 − n 1
n1
R.
2 (n 2 − n 1 )
n1
R.
2 (n 1 − n 2 )
2 n2
R.
n2 − n 1
n2
R.
n2 − n 1
n2
R.
2 (n 2 − n 1 )
n2
R.
2 (n 1 − n 2 )
Part 2 of 2 The lens is Chapter 36, section 11, Lensmaker’s Equation
1. divergent and the focal length is negative. 256 8. E, G, X, and K
9. Q, G, and X 2. convergent and the focal length is positive.
3. divergent and the focal length is positive.
4. convergent and the focal length is negative.
5. cannot be determined since the focal
length is zero. 10. Y, X, and E
Thin Lens 06
36:11, highSchool, multiple choice, > 1 min,
ﬁxed.
The magnitudes of the radii of curvature for the spherical surfaces A and B
are, respectively, RA  = a and RB  =
3 a.
The material of which the lens is
made has an index of refraction n = 1.5. 6. nonfocusing since the focal length is inﬁnite.
Lens Selection
36:11, highSchool, multiple choice, > 1 min,
wordingvariable. A Find the focal length of the following thin
lens
1. f = 3 a
2. f = 4 a
3. f = −4 a
4. f = 2 a Q G K X Y D E Which of the glass lenses above, when
placed in air, will cause parallel rays of light
to diverge? 5. f = a
6. f = −a 1. G, D, and E 7. f = −2 a 2. D, K, and Y 8. f = −3 a 3. Q, G, and D
4. D, Y, and E
5. K, Q, and Y
6. E, G, and K
7. K, Y, G, and E B Chapter 36, section 12, The Camera
Concept 28 E42
36:12, highSchool, multiple choice, < 1 min,
ﬁxed.
Cover the top half of a camera lens.
What eﬀect does this have on the pictures
taken?
1. The picture becomes darker.
2. The picture has only the top half of the
original image.
3. The picture has only the bottom half of
the original image.
4. The picture becomes smaller.
Conceptual 20 Q24
36:12, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
When you focus an optical instrument such
as a camera or microscope, what are you actually doing to the lens?
1. One lens is moving while other lens is
stationary.
2. Both lenses are moving with respect to
each other.
3. Lens aperture changes.
4. None of these
Part 2 of 2
What happens to the focal point of the image?
1. Remains the same
2. Changes 257 Chapter 36, section 13, The Eye and Corrective Lenses
Eyeglasses for farsighted
36:13, highSchool, numeric, > 1 min, normal.
A farsighted student has a near point of
100 cm.
Calculate the focal length of the glasses
needed so the near point will be normal
(25 cm). Neglect the space between the eyes
and the eyeglasses.
Holt SF 15Rev 64
36:13, highSchool, numeric, < 1 min, wordingvariable.
The distance from the front to the back of
your eye is approximately 1.90 cm.
If you can see a clear image of a book when
it is 35.0 cm from your eye, what is the focal
length of the lens/cornea system?
Holt SF 15Rev 65
36:13, highSchool, numeric, < 1 min, wordingvariable.
Suppose you look out the window and see
your friend, who is standing 15.0 m away.
To what focal length must your eye muscles
adjust the lens of your eye so that you may
see your friend clearly? Remember that the
distance from the front to the back of your
eye is about 1.90 cm. 258 Chapter 36, section 14, The Simple Magniﬁer
Holt SF 15B 02
36:14, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Sherlock Holmes examines a clue by holding
his magnifying glass (with a focal length of
15.0 cm) 10.0 cm away from an object.
a) Find the image distance.
Part 2 of 3
b) Find the magniﬁcation.
Part 3 of 3
c) Describe the image that he observes.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these
Holt SF 15Rev 43
36:14, highSchool, numeric, < 1 min, wordingvariable.
A magnifying glass has a converging lens of
focal length 15.0 cm.
At what distance from a nickel should you
hold this lens to get an image with a magniﬁcation of +2.00? 259 Chapter 36, section 16, The Telescope
Holt SF 14Rev 46
36:16, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 4
The real image of a tree is magniﬁed −0.085
times by a telescope’s primary mirror. The
tree’s image forms 35 cm in front of the mirror.
a) What is the distance between the mirror
and the tree?
Part 2 of 4
b) What is the focal length of the mirror?
Part 3 of 4
c) What is the value for the mirror’s radius of
curvature?
Part 4 of 4
d) Describe the image.
1. real, inverted, larger
2. virtual, inverted, larger
3. real, upright, larger
4. virtual, upright, larger
5. real, inverted, smaller
6. virtual, inverted, smaller
7. real, upright, smaller
8. virtual, upright, smaller
9. None of these 260 Chapter 37, section 1, Conditions for Interference
Concept 29 23
37:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Will the light from two very close stars
produce an interference pattern?
1. Yes; if they are very close to each other,
the light has large overlapping area.
2. Yes; strong light from the two stars creates very clear interference patterns.
3. No; light from two very close stars is not
likely to have the same frequency.
4. No; the light is too strong to produce a
discernable interference pattern. 261 Chapter 37, section 2, Double Slit Interference: Young’s Experiment
Concept 29 10
37:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Light illuminates two closely spaced thin
slits and produces an interference pattern on
a screen behind.
How will the distance between the fringes of
the pattern diﬀer for red light and blue light?
1. Closer for red light
2. Farther apart for red light
3. The same spacing for both
Concept 29 11
37:02, highSchool, multiple choice, < 1 min,
ﬁxed.
A double slit arrangement produces an interference fringe for yellow sodium light.
To produce narrowerspaced fringes, should
red light or blue light be used? 262 37:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is Young’s experiment more eﬀective
with slits than with the pinholes he ﬁrst used?
1. Pinholes can only be used in diﬀraction experiments because light transmitting
through two pinholes do not interfere with
each other.
2. It is hard to create pinholes with the same
size, which is important to the quality of the
interference pattern.
3. Slits form parallel straightline fringes,
which produce clearer interference patterns
than overlapping circular fringes.
4. None of these
Holt SF 16A 01
37:02, highSchool, numeric, < 1 min, wordingvariable.
A doubleslit interference experiment is
performed with light from a laser. The separation between the slits is 0.50 mm, and the
ﬁrstorder maximum of the interference pattern is at an angle of 0.059◦ from the center of
the pattern.
What is the wavelength of the laser light? 1. Blue
2. Red
3. Either
Concept 29 14
37:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What happens to the distance between interference fringes if the separation between
two slits is increased?
1. Increases Holt SF 16A 02
37:02, highSchool, numeric, > 1 min, wordingvariable.
Light falls on a double slit with slit separation of 2.02 × 10−6 m, and the ﬁrst bright
fringe is seen at an angle of 16.5◦ relative to
the central maximum.
What is the wavelength of the light? 2. Decreases
3. Remains unchanged Holt SF 16A 03
37:02, highSchool, numeric, > 1 min, wordingvariable. 4. The fringes disappear.
Concept 29 15 A pair of narrow parallel slits separated by
a distance of 0.250 mm are illuminated by the Chapter 37, section 2, Double Slit Interference: Young’s Experiment
green component from a mercury vapor lamp
(λ = 546.1 nm).
What is the angle from the central maximum to the ﬁrst bright fringe on either side of
the central maximum? 4. 546.173 nm Holt SF 16A 04
37:02, highSchool, numeric, > 1 min, wordingvariable. 263 7. Unable to determine. A pair of narrow parallel slits separated by
a distance of 0.250 mm are illuminated by the
green component from a mercury vapor lamp
(λ = 546.1 nm).
What is the angle from the central maximum to the second dark fringe on either side
of the central maximum?
Holt SF 16Rev 09
37:02, highSchool, numeric, > 1 min, wordingvariable.
Light falls on two slits spaced 0.330 mm
apart. The angle between the ﬁrst dark fringe
and the central maximum is 0.0800◦ .
What is the wavelength of the light?
Holt SF 16Rev 10
37:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A sodiumvapor street lamp produces light
that is nearly monochromatic. If the light
shines on a wooden door in which there are
two straight, parallel cracks, an interference
pattern will form on a distant wall behind the
door. The slits have a separation of 0.3096
mm, and the secondorder maximum occurs
at an angle of 0.21800◦ from the central maximum.
a) Determine the wavelength of the light.
1. 659.235 nm
2. 588.984 nm
3. 588.984 nm 5. None of these.
6. 656.326 nm Part 2 of 3
b) Determine the angle of the thirdorder
maximum.
Part 3 of 3
c) Determine the angle of the fourthorder
minimum.
Holt SF 16Rev 11
37:02, highSchool, numeric, > 1 min, wordingvariable.
All but two gaps within a set of venetian blinds have been blocked oﬀ to create a
doubleslit system. These gaps are separated
by a distance of 3.2 cm. Infrared radiation
is then passed through the two gaps in the
blinds. The angle between the central and
the secondorder maxima in the interference
pattern is 0.56◦ .
What is the wavelength of the radiation?
Holt SF 16Rev 28
37:02, highSchool, numeric, > 1 min, wordingvariable.
A doubleslit interference experiment is
performed using blue light from a hydrogen
discharge tube (λ = 486 nm). The ﬁfthorder
bright fringe in the interference pattern is
0.578◦ from the central maximum.
How far apart are the two slits separated?
Holt SF 16Rev 29
37:02, highSchool, numeric, > 1 min, wordingvariable.
A beam containing light of wavelengths of
λ1 and λ2 passes through a set of parallel slits.
In the interference pattern, the fourth bright
line of the λ1 light occurs at the same position Chapter 37, section 2, Double Slit Interference: Young’s Experiment
as the ﬁfth bright line of the λ2 light.
If λ1 is known to be 540.0 nm, what is the
value of λ2 ?
Holt SF 16Rev 31
37:02, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
In an arrangement to demonstrate doubleslit interference, λ = 643 nm, θ = 0.737◦ , and
d = 0.150 mm.
a) For light from the two slits interfering
at this angle, what is the path diﬀerence in
millimeters?
Part 2 of 3
b) What is the path diﬀerence in terms of the
number of wavelengths?
Part 3 of 3
c) Will the interference correspond to a maximum, a minimum, or an intermediate condition?
1. maximum
2. minimum
3. intermediate
4. None of these
5. Unable to determine 264 Chapter 37, section 4, Intensity Distribution of the DoubleSlit Interference
Double Slits 01
37:04, highSchool, numeric, > 1 min, normal. θ 19 mm S1 viewing
screen 0.092 mm Part 1 of 2
Two narrow parallel slits are illuminated
with light of wavelength 700 nm. S2 15 m
What is the phase diﬀerence between the
two interfering waves on a screen at a point
19 mm from the central bright fringe?
Part 2 of 2
What is the ratio of the intensity at this
point to the intensity at the center of a bright
fringe? 265 Chapter 37, section 5, Phasor Addition of Waves
MultiSlits 01
37:05, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 3
Given: The setup of a six slit diﬀraction
experiment shown in the ﬁgure. y 2
3
4 δ
L
Figure: Not drawn to scale.
Find the path diﬀerence diﬀerence between
two rays from adjacent slits which gives rise
to the ﬁrst minimum. 2. δ =
3. δ =
4. δ =
6. δ =
7. δ =
8. δ = 5. φ =
2. φ = 4. φ = 7. φ = 6 5. δ = 1. φ = 6. φ = 5 1. δ = rays from adjacent slits which gives rise to the
ﬁrst minimum. 3. φ = 1 1
λ
6
1
λ
4
1
λ
5
2
λ
5
3
λ
4
3
λ
5
2
λ
3
1
λ
2 9. δ = 2 λ 8. φ = 1
π
3
1
π
2
2
π
5
1
π
4
3
π
4
3
π
5
1
π
5
2
π
3 9. φ = 2 π
10. φ = π
Part 3 of 3
What is the phase angle diﬀerence between
two adjacent rays, at the principal maximum?
1. φ = 2 π
2. φ =
3. φ =
4. φ =
5. φ =
6. φ =
7. φ =
8. φ = 10. δ = λ
9. φ =
Part 2 of 3
Find the phase angle diﬀerence between two 266 1
π
3
2
π
3
1
π
4
1
π
2
3
π
4
2
π
5
3
π
5
4
π
5 10. φ = π Chapter 37, section 5, Phasor Addition of Waves 267 two adjacent rays, at the principal maximum?
MultiSlits 02
37:05, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 2
Given: The setup of a six slit diﬀraction
experiment shown in the ﬁgure. 1. φ = 2 π
2. φ =
3. φ =
4. φ = 1
y 2
3 5. φ =
6. φ = 4
7. φ = 5
6 8. φ = δ
L
Figure: Not drawn to scale.
Find the path diﬀerence diﬀerence between
two rays from adjacent slits which gives rise
to the ﬁrst minimum.
1. δ =
5. δ =
2. δ =
3. δ =
4. δ =
6. δ =
7. δ =
8. δ = 1
λ
6
1
λ
4
1
λ
5
2
λ
5
3
λ
4
3
λ
5
2
λ
3
1
λ
2 9. δ = 2 λ
10. δ = λ
Part 2 of 2
What is the phase angle diﬀerence between 9. φ = 1
π
3
2
π
3
1
π
4
1
π
2
3
π
4
2
π
5
3
π
5
4
π
5 10. φ = π
MultiSlits 03
37:05, highSchool, multiple choice, > 1 min,
wordingvariable.
Given: The setup of a four slit diﬀraction
experiment shown in the ﬁgure. y 1
2
3
4
δ
L Figure: Not drawn to scale.
Find the path diﬀerence diﬀerence between
two rays from adjacent slits which gives rise
to the ﬁrst minimum.
1. δ = 1
λ
4 Chapter 37, section 5, Phasor Addition of Waves
5. δ =
2. δ =
3. δ =
4. δ =
6. δ =
7. δ =
8. δ = 2. φ = 1
λ
5
1
λ
6
2
λ
5
3
λ
4
3
λ
5
2
λ
3
1
λ
2 3. φ =
4. φ =
6. φ =
7. φ =
8. φ = 268 2
π
5
1
π
4
3
π
4
3
π
5
1
π
5
2
π
3 9. φ = 2 π
10. φ = π 9. δ = 2 λ
MultiSlits 05
37:05, highSchool, multiple choice, > 1 min,
wordingvariable. 10. δ = λ
MultiSlits 04
37:05, highSchool, multiple choice, > 1 min,
wordingvariable.
Given: The setup of a six slit diﬀraction
experiment shown in the ﬁgure. Given: The setup of a ﬁve slit diﬀraction
experiment is shown in the ﬁgure below. 1 y 2 1
y 2
3 3
4
5 4 δ 5 L 6
δ
L
Figure: Not drawn to scale.
Find the phase angle diﬀerence between two
rays from adjacent slits which gives rise to the
ﬁrst minimum.
1
π
3
1
5. φ = π
2 1. φ = Figure: Not drawn to scale.
Find the phase angle diﬀerence and the
path diﬀerence between each pair of adjacent
rays which gives rise to the ﬁrst minimum.
2
π
5
1
2. φ = π
3
1
3. φ = π
2
2
4. φ = π
5 1. φ = and
and
and
and 1
5
1
δ=
5
1
δ=
5
1
δ=
6
δ= λ
λ
λ
λ Chapter 37, section 5, Phasor Addition of Waves
5. φ =
6. φ =
7. φ =
8. φ =
9. φ = 1
π
3
1
π
2
2
π
5
1
π
3
1
π
2 10. φ = π and δ =
and δ =
and δ =
and δ =
and δ =
and δ = 1
6
1
6
1
4
1
4
1
4 1
λ
2 λ
λ
λ
λ
λ 269 Chapter 37, section 6, Change of Phase Due to Reﬂection
Hewitt CP9 28 P08
37:06, highSchool, numeric, < 1 min, normal. 30 cm 30 cm Consider two ways that light might hypothetically get from its starting point S to its
ﬁnal point F by being reﬂected by a mirror at
either point A or point B. Since light travels
at a ﬁxed speed in air, the path of the least
time will also be the path of the least distance.
S
F
⊗
⊗ 40 cm
A 40 cm
B C Find the diﬀerence in the path lengths SAF
and SBF. 270 Chapter 37, section 7, Interference in Thin Films
An Optical Coating
37:07, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
A light ray is traveling in a medium with an
index of refraction n1 and it is reﬂected at the
boundary of a second medium with an index
of refraction n2 .
Considering the change of the relative
phases ∆φ due to their reﬂections, which of
the following conditions is correct? a wavelength λ = 500 nm and incident angle
θ ≈ 0, what is the minimum nonzero thickness
t of the coating?
1. t =
2. t =
3. t =
4. t =
5. t = 1. If n1 > n2 , then ∆φ = 0 and
if n1 < n2 , then ∆φ = 0. 6. t = 2. If n1 > n2 , then ∆φ = 0 and
π
if n1 < n2 , then ∆φ = .
2 7. t = 3. If n1 > n2 , then ∆φ = 0 and
if n1 < n2 , then ∆φ = π . 8. t = π
and
2
π
if n1 < n2 , then ∆φ = .
2
π
5. If n1 > n2 , then ∆φ = and
2
if n1 < n2 , then ∆φ = π . 9. t = 4. If n1 > n2 , then ∆φ = λ
8n
λ
4n
λ
2n
3λ
4n
λ
n
nλ
8
nλ
4
nλ
2
3nλ
4 10. t = n λ
An Optical Coating S
37:07, highSchool, multiple choice, > 1 min,
ﬁxed. 6. If n1 > n2 , then ∆φ = π and
if n1 < n2 , then ∆φ = π .
Part 2 of 2
Consider the optical coating on a glass lens
where the index of refraction of the coating
is n, where n is greater than the index of
refraction of the air.
12
θ ≈ 0◦ θ
air t 271 n
lens Assume: The index of refraction of the lens
is greater than that of the coating.
To minimize the reﬂection of a ray with A light ray is traveling in air with an index
of refraction of unity and it is reﬂected at the
boundary of a second medium with an index
of refraction n.
Consider the optical coating on a glass lens
where the index of refraction of the coating
is n, where n is greater than the index of
refraction of the air.
12
θ ≈ 0◦ θ
air t n
lens Assume: The index of refraction of the lens
is greater than that of the coating. Chapter 37, section 7, Interference in Thin Films
To minimize the reﬂection of a ray with a
wavelength 500 nm and incident angle θ ≈ 0,
what is the minimum nonzero thickness of the
coating?
1. t =
2. t =
3. t =
4. t =
5. t =
6. t =
7. t =
8. t =
9. t = λ
8n
λ
4n
λ
2n
3λ
4n
λ
n
nλ
8
nλ
4
nλ
2
3nλ
4 10. t = n λ
Coating on a Camera Lens 1
37:07, highSchool, numeric, > 1 min, normal.
A thin ﬁlm of cryolite ( nc = 1.35 ) is applied to a camera lens ( ng = 1.5 ). The
coating is designed to reﬂect wavelengths at
the blue end of the spectrum and transmit
wavelengths in the near infrared.
What minimum thickness gives high transmission at λ = 900 nm? Concept 29 25
37:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Because of wave interference a ﬁlm of oil on
water seems to be yellow to observers directly
above in an airplane.
What color does it appear to a scuba diver
directly below?
1. yellow
2. blue
3. black
4. none of these
Thin Film thickness
37:07, highSchool, multiple choice, > 1 min,
ﬁxed.
A material with index of refraction n = 1.3
is used to coat a piece of glass (nglass = 1.5).
What should be the minimum thickness of
this ﬁlm in order to minimize reﬂection of
light, which has a wavelength λ in vacuum?
1.
2.
3.
4.
5. Coating on a Camera Lens 2
37:07, highSchool, numeric, > 1 min, normal.
A thin ﬁlm of cryolite ( nc = 1.35 ) is applied to a camera lens ( ng = 1.5 ). The
coating is designed to reﬂect wavelengths at
the blue end of the spectrum and transmit
wavelengths in the near infrared.
What minimum thickness gives high reﬂectivity at 450 nm? 272 6.
7.
8.
9. λ
2
λ
3
λ
4
λn
2
λn
3
λn
4
λ
n
λ
2n
λ
3n Chapter 37, section 7, Interference in Thin Films
10. λ
4n 273 Chapter 38, section 1, Diﬀraction 274 TV signal in lower numbered channels.
Concept 29 02
38:01, highSchool, multiple choice, < 1 min,
ﬁxed.
In our everyday environment, diﬀraction is
much more evident for sound waves than for
light waves.
Why is this so? 2. Low frequency signals can carry more
information than high frequency signals.
3. Low frequency signals encounter less resistance from the air than high frequency signals
while traveling.
4. None of these 1. Light waves travel much faster than sound
waves.
2. Light waves have much shorter wavelength than sound waves.
3. We see light more often than we hear
sound in our everyday environment. Hewitt CP9 29 R03
38:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Is diﬀraction more pronounced through a
small or a large opening?
1. small 4. None of these
2. large
Concept 29 03
38:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why do radio waves diﬀract around buildings, while light waves do not?
1. Radio waves travel much slower than light
waves.
2. Radio waves are electromagnetic waves
while light waves are not.
3. Radio waves have a much longer wavelengths than light waves.
4. None of these
Concept 29 05
38:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why can TV channels of lower numbers
give better pictures in regions of poor TV
reception? (Lower channel numbers represent
lower carrier frequencies.)
1. Diﬀraction around buildings is easier for 3. It depends on the frequency of the light. Chapter 38, section 12, The Diﬀraction Grating
Concept 30 08
38:12, highSchool, multiple choice, < 1 min,
ﬁxed.
If we use a prism or a diﬀraction grating to
compare the red light from a common neon
tube and the red light from a helium neon
laser, what striking diﬀerence do we see?
1. The light from a common neon tube is
brighter.
2. The light from a common neon tube will
be diﬀracted into several shades of red light
while the light from a helium neon laser is
monochromatic.
3. The light from heilum neon laser is too
strong to be diﬀracted.
4. None of these
Holt SF 16B 01
38:12, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
A diﬀraction grating with 2.500 × 103
lines/cm is used to examine the sodium spectrum.
a) Calculate the angular separation of the
two closely spaced yellow lines of sodium
(588.995 nm and 589.592 nm) in the ﬁrst order. 275 A diﬀraction grating with 4525 lines/cm is
illuminated by direct sunlight. The ﬁrstorder
solar spectrum is spread out on a white screen
hanging on a wall opposite the grating.
a) At what angle does the ﬁrstorder maximum for blue light with a wavelength of 422
nm appear?
Part 2 of 2
b) At what angle does the ﬁrstorder maximum for red light with a wavelength of 655
nm appear?
Holt SF 16B 03 04
38:12, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A grating with is illuminated with light of
wavelength 565 nm.
a) What is the highestorder number that
can be observed if the grating has 1605
lines/cm? (Hint: Remember that sin θ can
never be greater than 1.)
Part 2 of 2
b) What is the highestorder number that
can be observed if the grating has 16050
lines/cm?
Holt SF 16B 05
38:12, highSchool, numeric, > 1 min, normal. Part 2 of 3
b) Calculate the angular separation for the
two lines in the second order. A diﬀraction grating is calibrated by using
the 546.1 nm line of mercury vapor. The
ﬁrstorder maximum is found at an angle of
21.2◦ .
Calculate the number of lines per centimeter on this grating. Part 3 of 3
c) Calculate the angular separation for the
two lines in the third order. Holt SF 16Rev 19 20
38:12, highSchool, numeric, > 1 min, wordingvariable. Holt SF 16B 02
38:12, highSchool, numeric, > 1 min, wordingvariable. Part 1 of 2
Light with a wavelength of 707 nm is
passed through a diﬀraction grating with 795
slits/cm.
a) Find the angle at which one would ob Part 1 of 2 Chapter 38, section 12, The Diﬀraction Grating
serve the ﬁrstorder maximum.
Part 2 of 2
b) If the wavelength of the light were 353
nm, at what angle would the secondorder
maximum appear?
Holt SF 16Rev 21
38:12, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 6
By attaching a diﬀractiongrating spectroscope to an astronomical telescope, one
can measure the spectral lines from a star
and determine the star’s chemical composition. Assume the grating has 3661 slits/cm.
The wavelengths of the star’s light are
λ1 = 478.500 nm, λ2 = 647.400 nm, and
λ3 = 696.400 nm.
a) Find the angle at which the ﬁrstorder
spectral line for λ1 occurs.
Part 2 of 6
b) Find the angle at which the ﬁrstorder
spectral line for λ2 occurs.
Part 3 of 6
c) Find the angle at which the ﬁrstorder
spectral line for λ3 occurs.
Part 4 of 6
d) Find the angle at which the secondorder
spectral line for λ1 occurs.
Part 5 of 6
e) Find the angle at which the secondorder
spectral line for λ2 occurs.
Part 6 of 6
f) Find the angle at which the secondorder
spectral line for λ3 occurs.
Holt SF 16Rev 26
38:12, highSchool, numeric, > 1 min, normal.
The 546.1 nm line in mercury is measured
at an angle of 81◦ in the thirdorder spectrum
of a diﬀraction grating. 276 Calculate the number of lines per milimeter
for the grating.
Holt SF 16Rev 30
38:12, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
Visible light from an incandescent light
bulb ranges from 400.0 nm to 700.0 nm. When
this light is focused on a diﬀraction grating,
the entire ﬁrstorder spectrum is seen, but
none of the secondorder spectrum is seen.
a) What is the maximum spacing between
lines on this grating?
Part 2 of 2
b) What is the minimum spacing between
lines on this grating? Chapter 39, section 3, Postulates: Speed of Light 277 1. Yes.
Concept 35 04
39:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose that a person riding on the top of
a freight car shines a searchlight beam in the
direction in which the train is traveling.
How does the speed of the light beam relative to the ground compare to the speed of
beam when the train is at rest?
1. Faster 2. No.
Concept 35 10
39:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose that the light bulb in the rocket
ship (shown in the ﬁgures below) is closer to
the front than to the rear of the compartment,
so that the observer in the ship sees the light
reaching the front before it reaches the back. 2. Slower
3. No change
Concept 35 07
39:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Light travels more slowly in glass than in
air.
Does this contradict the theory of relativity?
1. Yes; the theory of relativity cannot be
applied in a transparent medium.
2. Yes; but the theory of relativity is correct
in air.
3. No; another theory supports the contradiction.
4. No; the speed of light in space is constant.
Concept 35 08
39:03, highSchool, multiple choice, < 1 min,
ﬁxed.
If two lightning bolts hit exactly the same
place at exactly the same time in one frame of
reference, is it possible that observers in other
frames will see the bolts hitting at diﬀerent
times or at diﬀerent places? Is it still possible that an outside observer
will see the light reaching the back ﬁrst?
1. Yes
2. No
Concept 35 12
39:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Can an electron beam sweep across the face
of a cathoderay tube at a speed greater than
the speed of light, and why?
1. Yes; though no material nor information
can travel faster than light.
2. Yes; some material moves faster than
light.
3. No; nothing is faster than light.
4. No; only an electron travel faster than
light.
Conceptual 28 03
39:03, highSchool, multiple choice, < 1 min, Chapter 39, section 3, Postulates: Speed of Light
ﬁxed.
Astronomers have routinely observed distant galaxies moving away from the Milky
Way galaxy at speeds over 10% of the speed
of light (30,000 km/s).
At what speed does this distant light reach
astronomers?
1. 60000 km/s
2. 30000 km/s
3. 15000 km/s
4. 10000 km/s
5. 7500 km/s
Conceptual 28 Q18
39:03, highSchool, multiple choice, < 1 min,
normal.
Someone shines a light while moving toward
you at 1000 m/s.
With what speed will the light strike you?
(The speed of light is 300,000,000 m/s) 278 Chapter 39, section 4, The MichelsonMorley Experiment
Concept 35 05
39:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why did Michelson and Morley at ﬁrst consider their experiment a failure?
1. They ignored the experimental errors.
2. They did not have the equipment they
originally wanted.
3. They did not conﬁrm the expected result.
4. They did not measure the exact quantities. 279 Chapter 39, section 5, Consequences of Special Relativity
Concept 35 01
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
The idea that force causes acceleration
doesn’t seem strange. This and other ideas of
Newtonian mechanics are consistent with our
everyday experience.
Why do the ideas of relativity seem
strange?
1. The eﬀects of relativity become apparent
only at very high speeds very uncommon to
everyday experience.
2. The principles of relativity apply outside
Earth. 280 ﬁres a gun pointed forward.
Relative to the ground, is the bullet moving faster or slower when the train is moving
than when it is standing still? Relative to
the freight car, is the bullet moving faster or
slower when the train is moving than when
the train is standing still?
1. Faster; faster
2. Faster; the same
3. Faster; slower
4. Slower; faster
5. Slower; the same
6. The same; the same 3. For the eﬀects of relativity to become
apparent large masses are needed. 7. The same; faster 4. Earth’s rotation doesn’t let us observe
relativity that applies to systems moving in
straight trajectories. Concept 35 06
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 35 02
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. When you drive down the highway you are
moving through space.
What else are you moving through? If you were in a smoothriding train with
no windows, could you sense the diﬀerence
between uniform motion and rest or between
accelerated motion and rest? 1. Time
2. Dimension
3. Length 1. Only accelerated motion can be sensed.
4. Speed
2. Only uniform motion can be sensed.
3. Both acclerated and uniform motion can
be sensed.
4. No motion can be sensed.
Concept 35 03
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 35 09
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Event A occurs before event B in a certain
frame of reference.
How could event B occur before event A in
some other frame of reference?
1. It’s impossible. A person riding on the roof of a freight train Chapter 39, section 5, Consequences of Special Relativity
2. Its a matter of relative distance.
3. The spaces are distorted.
4. It’s a matter of relative velocity.
Concept 35 11
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
The speed of light is a speed limit in the
universe, at least for the fourdimensional universe we comprehend. No material particle
can attain or surpass this limit even when a
continuous, unremitting force is exerted on it.
Why is this so?
1. The momentum of an object has a limit.
2. It is contradictory to the theory of relativity. 281 things.
3. The moving points are imaginary.
4. This is an exception of the theory of special relativity.
Concept 35 18
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Is it possible for a son or daughter to be
biologically older than his or her parents?
1. Yes if the parents travel very long time in
a highspeed space ship.
2. Yes if the child travels very long time in a
highspeed space ship.
3. No; children always stay younger than
their parents. 3. The photon has a speed limit.
4. Time dilations makes it impossible.
4. Light vanishes when it travels faster than
c.
Concept 35 13
39:05, highSchool, multiple choice, < 1 min,
xed.
Consider the speed of the point where scissors blades meet when scissors are closed. The
closer the blades are to being closed, the faster
the point moves. The point could, in principle, move faster than light. Likewise for the
speed of the point where an ax meets wood
when the ax blade meets the wood almost
horizontally. The contact point travels faster
than the ax. Similarly, a pair of laser beams
that are crossed and moved toward being parallel produce a point of intersection that can
move faster than light.
Why do these examples not contradict special relativity? Concept 35 19
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If you were in a rocket ship traveling away
from the Earth at a speed close to the speed
of light, what changes would you note in your
pulse? In your volume?
1. Slower pulse and smaller volume
2. Faster pulse and larger volume
3. No changes; you observed yourself in the
same reference frame.
4. No changes because of time dilation
Concept 35 20
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. 1. The moving points are not massive.
2. The moving points are not material If you were on Earth monitoring a person in
a rocket ship traveling away from the Earth Chapter 39, section 5, Consequences of Special Relativity
at a speed close to the speed of light, what
changes would you note in his pulse? In his
volume?
1. Slower pulse and smaller volume
2. Faster pulse and larger volume
3. No changes; you are in the diﬀerent reference frame from him.
4. No changes because of time dilation
Concept 35 22
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
How does the measured density of a body
in motion compare to its density at rest? 282 length decreases and vice versa.
Concept 35 25
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Light is reﬂected from a moving mirror.
How is the reﬂected light diﬀerent from the
incident light and how is it the same?
1. The frequency changes, and both the
wavelength and the speed of light stay the
same.
2. Both the frequency and the wavelength
change, and the speed of light stays the
same.
3. The wavelength changes, and both the frequency and the speed of light stay the same. 1. Increases
2. Decreases
3. The density cannot be measured when
bodies move very fast. 4. No change in the frequency, the wavelength, nor the speed of light.
Concept 35 30
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. 4. No diﬀerence
Concept 35 24
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
The formula relating speed, frequency, and
wavelength of electormagnetic waves, c = f ν ,
was known before relativity was developed.
Relativity has not changed this equation
but it has added which new feature to it? Part 1 of 3
Electrons end their trip down the Stanford
accelerator with an energy thousands of times
their rest energy.
In theory, if you could travel with them,
would you notice an increase in their energy?
1. Electrons would have the same increase
in energy.
2. Electrons would have their rest energy. 1. The speed of light is a constant in all
reference frames.
2. The frequency is dependent on the reference frames.
3. The wavelength is changed by the reference frames.
4. As the frequency increases, the wave 3. Electrons would have zero energy.
4. Electrons’ energy would increase, but not
as much as in the accelerator’s frame of reference.
Part 2 of 3
Would you notice an increase in their momentum? Chapter 39, section 5, Consequences of Special Relativity
1. Electrons would have the same relativistic
momentum.
2. Electrons would have zero momentum.
3. Electrons would have a classical nonzero
momentum.
4. Electrons’ momentum would increase, but
not as much as in the accelerator’s frame of
reference. 283 Concept 35 32
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
A chunk of radioactive material encased in
an idealized perfectly insulating blanket gets
warmer as its nuclei decay and release energy.
How do the masses of the radioactive material and the blanket, respectively, change?
1. Decreases; decreases
2. Decreases; increases
Part 3 of 3
In your moving frame of reference, what would
be the approximate speed of the target they
are about to hit?
1. Much less than the speed of light
2. Equal to the speed of light
3. Close to the speed of light
4. Greater than the speed of light
Concept 35 31
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Two safety pins, identical except that one
is latched and one is unlatched, are placed in
identical acid baths.
After the pins are dissolved, what, if anything, is the diﬀerence in the two acid baths?
1. The bath that dissolved the latched pin
will be colder and more massive.
2. The bath that dissolved the unlatched
pin will have more mass than that of latched
pin.
3. The unlatched pin will not be dissolved,
while the latched pin will be dissolved well.
4. The bath that dissolved the unlatched pin
will be colder with no diﬀerence in mass. 3. Increases; increases
2. Increase; decrease
Concept 35 33
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
The electrons that illuminate the screen
in a typical television picture tube travel
at nearly onefourth the speed of light and
have nearly 3% more energy than hypothetical nonrelativistic electrons traveling at the
same speed.
Does this relativistic eﬀect tend to increase
or decrease your electic bill?
1. Increases; the relativistic electrons require
extra momentum and energy.
2. Decreases; the relativistic electrons travel
very fast.
3. No eﬀect; there is no change in momentum and energy of relativistic electrons.
4. Your bill is independent of the momentum
and energy of electrons.
Concept 35 34
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Can the idea of the correspondence principle be applied outside physical science? Chapter 39, section 5, Consequences of Special Relativity 284 cally.
1. Yes; it just makes good sense.
2. No; it does not work outside of physics.
3. No; it works only in the relativistic
physics.
4. The correspondence principle is not valid
these days.
Concept 35 38
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
One of the fads of the future might be “century hoping,” where occupants of highspeed
spaceships would depart from the Earth for
several years and return centuries later.
What are the presentday obstacles to such
a practice?
1. We are in the same frame of reference. 4. No; the theory does not show that time
dilation has no limit.
Concept 36 01
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
An astronaut awakes in her closed capsule,
which actually sits on the moon.
Can she tell whether her weight is the result
of gravitation or of accelerated motion?
1. She can tell her weight is the result of
gravitation.
2. She knows her weight is caused by accelerated motion.
3. She can feel both of them.
4. She does not recognize the diﬀerence between them. 2. We cannot distort the time space.
3. We cannot live in the rocket which travels
at the speed of light.
4. We do not have enough energy to accelerate to the speed of light.
Concept 35 39
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Is the statement by the philosopher
Kierkegaard that “Life can only be understood backwards; but it must be lived forwards” consistent with the theory of special
relativity? Concept 36 02
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
You wake up at night in your berth on a
train to ﬁnd yourself being “pulled” to one
side of the train. You naturally assume that
the train is rounding a curve but you are
puzzled that you don’t hear any sounds of
motion.
Which of the following is NOT a possible
explanation?
1. The train has stopped on a banked section
of a track. 1. Yes; the theory shows that there are various frames of reference. 2. The train has stopped next to some superdense matter to which you are highly attracted. 2. Yes; the theory does not provide for traveling backward in time. 3. The car is leaning because of a derailment. 3. No; we can travel backward theoreti 4. Only acceleration around a curve can Chapter 39, section 5, Consequences of Special Relativity
cause their eﬀect.
Concept 36 03
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Since gravity can duplicate the eﬀects of
acceleration, it can also balance the eﬀects
of acceleration. How and when can an astronaut experience no net force (as measured
by a scale) because of the canceling eﬀects of
gravity and acceleration?
1. When an astronaut is being launched, the
eﬀect of gravity and the eﬀect of the thrust
force of rocket cancel.
2. When an astronaut is in orbit, the effect of gravity and the eﬀect of the frame’s
acceleration cancel.
3. When an astronaut travels in a spaceship
in the universe, no gravity acts on his or her
body.
4. When an astronaut travels at the speed
of light, he or she cannot feel any force.
Concept 36 04
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
An astronaut is provided a “gravity” when
the ship’s engines are activated to accelerate
the ship. This requires the use of fuel.
Is there a way to accelerate and provide
“gravity” without the sustained use of fuel?
1. If the ship travels with the constant acceleration, an astronaut in it feels “gravity”.
2. Once the ship reaches the speed of light,
an astronaut feels “gravity” and there is no
consumption of fuel.
3. If the ship is set into rotation, an astronaut experiences “gravity” without the consumption of fuel. 285 4. Any “gravity” requires the sustained use
of fuel.
Concept 36 05
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
In his famous novel Journey to the Moon,
Jules Verne stated that occupants in a spaceship would shift their orientation from up to
down when the ship crossed the point where
the moon’s gravitation became greater than
the Earth’s.
Is this correct?
1. Yes; the space ship travles with a constant
acceleration, so the occupants recognize up or
down.
2. Yes; the moon’s gravitation and the
Earth’s one are the occupants recognize the
up or down.
3. No; the occupants travel very fast near a
huge gravitational object (the moon and the
Earth) so they have no sense of up or down.
4. No; the occupants are in the state of
freefall and have no sense of up or down.
Concept 36 06
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
What happens to the separation distance
between two people if they both walk north
at the same rate from two diﬀerent places on
the Earth’s equator? And just for fun, where
in the world is a step in every direction a step
south?
1. Decrease; at the north pole.
2. Decrease; at the south pole.
3. Increase; at the north pole.
4. Increase; at the south pole. Chapter 39, section 5, Consequences of Special Relativity
Concept 36 07
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
We readily note the bending of light by
reﬂection and refraction, but why is it we do
not ordinarily notice the bending of light by
gravity?
1. The Earth is too small to notice the effect.
2. Light travels too fast to notice the eﬀect
in our everyday life.
3. The gravities of the Sun, the Moon, and
other planets make the eﬀect vanish.
4. The gravity of the Earth is too weak for
us to notice the eﬀect. 286 its otherwise straightline path in a gravitational ﬁeld of 1 g .
By what distance would a beam of light
drop from its otherwise straightline path if it
traveled in a uniform ﬁeld of 1 g for 1 s?
Part 2 of 2
For 2 s?
Concept 36 10
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Light changes its energy when it “falls” in
a gravitational ﬁeld. This change in energy is
not evidenced by a change in speed, however.
What is the evidence for this change in
energy?
1. The polarization state is inverted. Concept 36 08
39:05, highSchool, multiple choice, < 1 min,
ﬁxed. 2. The electric ﬁeld of light is changed. Why do we say that light travels in straight
lines? Is it strictly accurate to say that a
laser beam provides a perfectly straight line
for purposes of surveying? 4. The light is red shifted. 1. Yes; the main character of a laser is that
it travels in a perfect straight line.
2. Yes; the principle of the laser beam is
based on the stimulated emission of radiation.
3. No; the laser beam travels in an almost
straight line, not perfect.
4. No; the laser beam is distorted near very
huge objects.
Concept 36 09
39:05, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
At the end of 1 s, a horizontally ﬁred bullet
has dropped a vertical distance of 4.9 m from 3. The intensity of light is lowered. Concept 36 24
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does the gravitational attraction between the sun and Mercury vary? Would it
vary if the orbit of Mercury were perfectly
circular?
1. The orbit of Mercury about the sun is
not perfect circle; no variation of the sun’s
gravitational ﬁeld.
2. The mass of Mercury charges during its
orbit; no variation of the Sun’s gravitational
ﬁeld.
3. A comet travels near Mercury periodically; no variation of the Sun’s gravitational
ﬁeld.
4. Mercury is located very close to the sun; Chapter 39, section 5, Consequences of Special Relativity
no variation of the sun’s gravitational ﬁeld.
Concept 36 27
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Based on what you know about the emission and absorption of electromagnetic waves,
how are gravitational waves are emitted or
absorbed? (Scientists seeking to detect gravitational waves must arrange for them to be
absorbed.)
1. A gravitation ﬁeld is distorted. 287 1. accelerated, uniformly moving, accelerated
2. uniformly moving, accelerated, accelerated
3. All are accelerated.
4. All are uniformly moving.
5. accelerated, uniformly moving, uniformly
moving
6. uniformly moving, accelerated, uniformly
moving 2. A radiation is detected.
3. Masses oscillate.
4. Charges oscillate.
Conceptual 28 08
39:05, highSchool, numeric, < 1 min, normal.
Calculate the Lorentz factor for objects
traveling at 99.9% of the speed of light.
Conceptual 28 09
39:05, highSchool, numeric, < 1 min, normal.
What is the apparent mass of a 1kg object that has been accelerated to 99% of light
speed?
Conceptual 28 Q01
39:05, highSchool, multiple choice, < 1 min,
wordingvariable.
For each of the following situations specify
whether you are in a uniformly moving reference frame or an accelerated reference frame,
respectively.
A. You are in your car, slowing down to make
a stop;
B. You are ﬂoating deep in space, far from
the eﬀects of gravity;
C. You are standing still on the surface of the
earth. 7. uniformly moving, uniformly moving, accelerated
8. accelerated, accelerated, uniformly moving
Conceptual 28 Q02
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Imagine taking a ride on a perfectly quiet
train that rides on a perfectly smooth and
straight tracks.
If the train is moving at a constant speed
and you throw a ball straight up, it appears
as though
1. it is falling straight back down
2. it is falling backwards
3. it is falling forward
4. it is not falling
Part 2 of 2
If the train is accelerating forward, the ball
1. is falling straight back down
2. is falling backwards Chapter 39, section 5, Consequences of Special Relativity 288 3. is falling forward
2. the backward laser light moves faster.
4. is not falling
3. they both move at the same speed.
Conceptual 28 Q03
39:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
You are riding on a ﬂatbed truck moving
at 50 kilometers per hour. You have two
identical guns, one aimed forward and one
aimed backward, and you ﬁre them at the
same time.
According to an observer in the ground,
1. the forward bullet appears to move
faster.
2. the backward bullet appears to move
faster.
3. they both appear to move at the same
speed. Part 2 of 2
According to an observer on the truck
1. the forward laser light moves faster.
2. the backward laser light moves faster.
3. they both move at the same speed.
Conceptual 28 Q08
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Does relativity theoretically allow you to go
backward in time into the past?
1. Yes
2. No Part 2 of 2
According to an observer on the truck,
1. the forward bullet appears to move
faster.
2. the backward bullet appears to move
faster. Part 2 of 2
An object travelling at the speed of light can
be accelerated all the way to (or faster than)
the speed of light.
1. true
2. false 3. they both appear to move at the same
speed.
Conceptual 28 Q04
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
You are riding on a ﬂatbed truck moving
at 100 kilometers per hour. You have two
identical lasers, one aimed forward and one
aimed backward.
According to an observer in the ground, Conceptual 28 Q10
39:05, highSchool, multiple choice, < 1 min,
wordingvariable.
As you ride in an elevator, when is the
apparent acceleration smaller than the acceleration due to gravity outside the elevator (on
the surface of the Earth)?
1. when the elevator is accelerating downward
2. when the elevator is at rest 1. the forward laser light moves faster. Chapter 39, section 5, Consequences of Special Relativity
3. when the elevator is accelerating upward
Conceptual 28 Q11
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If you are in a spaceship far from the reaches
of gravity, under what conditions will it feel to
you as if the spaceship were sitting stationary
on Earth’s surface?
1. when the tidal eﬀects of sun is not present
2. when the spaceship is accelerating at 9.81
m/s2
3. when the spaceship is at rest
4. when the spaceship is inﬂuenced by the
gravitational force of another planet
Conceptual 28 Q14
39:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is it that we don’t ordinarily notice
the bending of light?
1. Light travels at a very high speed.
2. Light doesn’t really bend.
3. What few light rays that bend are overpowered by those that do not bend.
Conceptual 28 Q19
39:05, highSchool, numeric, < 1 min, normal.
If you can do 39 pushups on the surface of
Earth, how many can you do in a spaceship,
far from gravity, accelerating at g ? 289 Chapter 39, section 6, The Lorentz Transformation for Displacements
Concept 35 23
39:06, highSchool, multiple choice, < 1 min,
ﬁxed.
If stationary observers measure the shape of
a passing object to be exactly circular, what is
the shape of the object according to observers
traveling with it?
1. It depends on the speed of object.
2. It’s also circular.
3. It’s an ellipse (shorter in the direction of
motion).
4. It’s an ellipse (longer in the direction of
motion).
Concept 35 29
39:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does the twomile linear accelerator at
Stanford University in California “appear” to
be less than a meter long to the electrons that
travel in it.
1. Electrons travel faster than the speed of
light. 290 What is the width of the building as measured by a friend standing at rest next to the
building?
Part 2 of 2
What height of the building would be measured by the friend?
Conceptual 28 Q13
39:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Due to the length contraction, you notice
that a passing train appears to be shorter
than when it is stationary.
What do the people in the train observe
about you?
1. They observe you to appear longer than
when you are at stationary.
2. They observe you to appear as you are at
stationary.
3. They observe you to appear shorter than
when you are at stationary
Problems 35 06
39:06, highSchool, numeric, < 1 min, normal. 2. The decrease in volume makes the electron smaller. A bus moving at 0.99 c is 70 feet long
according to its passengers and driver.
What is its length from your vantage point
on a ﬁxed planet? 3. Length contraction reduces the apparent
length. Problems 35 08
39:06, highSchool, numeric, < 1 min, normal. 4. Time dilation makes the lifetime of electrons longer. A bus is 70 feet long according to its passengers and driver.
If the bus driver decided to drive at 0.9999 c
in order to make up some time, what would
you measure the length of the bus to be? Conceptual 28 05
39:06, highSchool, numeric, < 1 min, normal.
Part 1 of 2
Elliot is traveling by a building at
150000 km/s, moving along the width of the
building. He measures the building to be 50 m
wide and 100 m tall. Chapter 39, section 7, The Lorentz Transformation for Time 291 1. Possible only if he travels very long time formed high in the atmosphere by the interactions of cosmic rays with atomic nuclei in the
upper atmosphere. They receive a lot of energy from the original cosmic ray and travel
at speeds close to the speed of light. Muons
have an average lifetime of about two millionths of a second and according to classical
physics should decay before reaching the sea
level. Laboratory measurements, however,
show that muons in great number do reach
the Earth’s surface.
What is the explanation? 2. Possible only if he travels at the speed of
light 1. Muons travel faster as they enter the lower
atmosphere. 3. Impossible; only the speed of aging can
change. 2. The timing in the muons’ frame of reference is diﬀerent from ours. Concept 35 17
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
A twin who makes a long trip at relativistic
speeds returns younger than his twin sister
who stayed at home.
Could he return before his twin sister was
born? 4. Time dilation makes it impossible.
Concept 35 21
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
If you lived in a world where people regularly traveled at speeds near the speed of
light, why would it be risky to make a dental
appointment for 10:00 AM next Thursday?
1. You and your dentist are in the diﬀerent reference frames; your clock and his will
indicate diﬀerent times.
2. Spaces around you and your dentist are
distorted; you cannot meet him.
3. You and your dentist will be in diﬀerent time space, and your watches cannot be
synchronized. 3. Muons interact with some particles in the
air.
4. Experimental physics is wrong.
Concept 35 37
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
When we look out into the universe, we
see the past. John Dobson, founder of the
San Francisco Siderwalk Astronomers, says
that we cannot even see the backs of our own
hands now. In fact, we can’t see anything
now. Do you agree?
1. Yes; there is always a ﬁnite time interval
between an event and our perception of it.
2. Yes; we cannot see the future events.
3. No; our hands are very close to our eyes. 4. Time dilation confuses you and your dentist about the correct time.
Concept 35 36
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Muons are elementary particles that are 4. No; we cannot recognize the time interval.
Concept 36 11
39:07, highSchool, multiple choice, < 1 min,
ﬁxed. Chapter 39, section 7, The Lorentz Transformation for Time
Would we notice a slowing down or speeding up of a clock if we carried it to the bottom
of a very deep well?
1. The clock will run slower. 292 the center of a rotating kingdom. Charity
goes to live at the edge of the kingdom for a
time and then returns home.
Which twin is older when they rejoin? (Ignore any timedilation eﬀects associated with
travel to and from the edge.) 2. The clock will run faster.
1. Prudence
3. The clock will run the same as at the
surface.
Concept 36 15
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Will a clock at the equator run slightly
faster or slightly slower than an identical clock
at one of the Earth’s poles?
1. The clock runs slower.
2. The clock runs faster.
3. The clocks run the same.
4. The speed of clock depends on the position at the equator.
Concept 36 16
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Splitting hairs, should a person who worried about growing old live at the top or at
the bottom of a tall apartment building? 2. Charity
3. There will be no diﬀerence.
4. More information is needed.
Conceptual 28 04
39:07, highSchool, numeric, < 1 min, normal.
Anna is watching the stars late at night
when she sees a spaceship pass at 80% of the
speed of light; 10 seconds pass on Earth as she
watches a clock on the spaceship.
How much time passes on the spaceship
clock?
Conceptual 28 Q06
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
You and a friend buy two identical watches.
Some days later you see your friend travelling
relative to you at 25% of the speed of light.
Which watch is running factor?
1. friend’s 1. At the top 2. yours 2. At the bottom 3. same speed 3. There will be no diﬀerence. Conceptual 28 Q07
39:07, highSchool, numeric, < 1 min, normal. 4. It depends on the growth speed.
Concept 36 17
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Prudence and Charity are twins raised at You take your pulse while sitting in your
room and you measure 57 beats per minute
(bpm).
All else being equal, what would your pulse
measure if you took it while on a fastmoving
train? Chapter 39, section 7, The Lorentz Transformation for Time
Conceptual 28 Q15
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
To an outside observer, where would you
appear to age faster?
1. on top of a mountain
2. at the sea level
3. 100 m below sea level 293 Conceptual 28 Q20
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
You are jealous of your younger brother,
who looks very young for his age. You are
interested in reducing the rate at which you
age relative to him. Having heard of general
relativity and the eﬀect of gravity on time,
you decide that you need to spend more time
at an altitude that makes you age more slowly
relative to your brother.
Using only gravity considerations, which
job would meet your needs? 4. in the space station
1. park ranger high in the mountains
Conceptual 28 Q16
39:07, highSchool, multiple choice, < 1 min,
ﬁxed. 2. a worker at a space station
3. a taxi cab driver at sea level You’ve decided to let your sister, a NASA
astronaut, cook the Thanksgiving turkey this
year. Normally the turkey takes 6 hours to
cook, but your sister decides to cook it on
her spaceship while travelling at close to the
speed light. According to your watch, she was
gone for 6 hours.
What was the condition of the turkey?
1. The turkey was overcooked.
2. The turkey was undercooked.
3. The turkey was just right.
Conceptual 28 Q17
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Because of relative motion, you notice a
friend’s clock running slowly.
How does your friend view your clock?
1. running faster than his clock
2. running slower than his clock 4. a miner at below sea level
Problems 35 01
39:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider a highspeed rocket ship equipped
with a ﬂashing light source.
If the frequency of ﬂashes when the ship
is approaching is twice what it was when the
ship was a ﬁxed distance away, by how much
is the period (time interval between ﬂashes)
changed? Is this period constant for a constant relative speed? For accelerated motion?
Defend your answer.
1. Each ﬂash has less distance and the frequency increase more, and the period decrease
more as well.
2. Each ﬂash has the same distance and the
frequency increase more, but the period is
constnat.
3. Each ﬂash has the same distance and the
frequency and the period are also constant. 3. running the same
4. Each ﬂash has more distance and the Chapter 39, section 7, The Lorentz Transformation for Time
frqeuency decrease more, and the period increase more as well .
Problems 35 04
39:07, highSchool, numeric, < 1 min, normal.
A passenger on an interplanetary express
bus traveling at v =0.99 c takes 5 minutes
catnap by his watch.
How long does the nap last from your vantage point on a ﬁxed planet?
Problems 35 07
39:07, highSchool, numeric, < 1 min, normal.
A passenger on an interplanetary express
bus traveling at 0.1 c takes 5 minutes catnap
by his watch.
How long would you measure the passenger’s catnap to be?
Problems 35 09
39:07, highSchool, numeric, < 1 min, normal.
Assume that rocket taxis of the future move
about the solar system at 0.5 c . For a 1 hour
trip as measured by a clock in the taxi, a
driver is paid 10 stellars. The taxi driver’s
union demands that pay be based on Earth
time instead of taxi time.
If their demand is met, what will be the
new pay for the same trip? 294 Chapter 39, section 8, The Lorentz Transformation for Velocities
Conceptual 28 06
39:08, highSchool, numeric, < 1 min, normal.
An interplanetary spaceship has windows
that are 3 meters wide.
How fast must it pass by a planet so that an
observer on that planet measures the width of
the windows to be 1.5 meters?
Conceptual 28 10
39:08, highSchool, numeric, < 1 min, ﬁxed.
If a moving clock appears to be ticking onehalf as fast as normal, at what percentage of
light speed is traveling? 295 The starship Enterprise, passing the Earth
at 0.8 c , sends a drone ship forward at 0.5 c
relative to the Enterprise.
What is the drone’s speed relative to the
Earth? (Where, c is the speed of light)
Problems 35 03
39:08, highSchool, numeric, < 1 min, ﬁxed.
Pretend that the starship Enterprise in the
previous problem is somehow traveling at c
with respect to the Earth, and it ﬁres a drone
forward a speed c with respect to itself.
Using the equation for the relativistic addition of velocities, what is the speed of the
drone with respect to the Earth? Figuring Physics 07
39:08, highSchool, multiple choice, < 1 min,
ﬁxed. 1. 0.5c Assume: The sun passes between the Earth
and a pair of stars as shown below, and the
moon passes in from of the sun and totally
eclipses it so the stars are visible. 3. c 2. 0.98c 4. 2c
Relative Speeds
39:08, highSchool, multiple choice, > 1 min,
ﬁxed. STAR STAR
SUN MOON
OBSERVER According to General Relativity, the stars
will appear to be slightly
1. closer together.
2. farther apart. A ﬂashbulb is placed in the middle of a
bus. When the ﬂashbulb goes oﬀ, light from
the bulb strikes the rear and front of the bus
simultaneously, as seen by an observer, Karl,
sitting in the bus.
As seen by another observer, Fred, standing
on the curb as the bus moves past, the light
1. hits the front of the bus slightly before it
hits the rear.
2. hits the rear of the bus slightly before it
hits the front. 3. distorted, but not closer or farther
apart. 3. hits the front and back of the bus simultaneously. Problems 35 02
39:08, highSchool, numeric, < 1 min, normal. 4. Not enough information to form a conclusion. Chapter 39, section 8, The Lorentz Transformation for Velocities
Relativistic Speeds 02
39:08, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Our hero is ﬁred upon by the dastardly
space villain whose space howitzer has a muzzle velocity of 0.5 c . Moreover, the space
villain is speeding toward our hero at 0.7 c
when she ﬁres her evil weapon?
How fast does our hero see the projectile
rushing at him (as a multiple of c)?
Assume: The positive direction is from our
hero towards the dastardly space villain.
Part 2 of 2
Our hero sees the weapon ﬁred from a mere
1 Gm away.
How long does he have to raise his deﬂector
screens? (Remember, it also takes some time
for the light to get to him, and the projectile
is already on its way.) The speed of light is
3 × 108 m/s. 296 Chapter 39, section 9, Relativistic Momentum and Relativistic Form of
Concept 35 26
39:09, highSchool, multiple choice, < 1 min,
ﬁxed.
As a meter stick moves past you, your measurments show its momentum to be twice its
classical momentum and its length to be 1 m.
In what direction is the stick pointing?
1. Along the direction of motion
2. Perpendicular to the direction of motion
3. 60◦ to the direction of motion
4. 30◦ to the direction of motion
Concept 35 27
39:09, highSchool, multiple choice, < 1 min,
ﬁxed.
If a meter stick is moving with a relativistic
momentum that is twice its classical momentum in a direction along its length (like a
properly thrown spear), how long will you
measure its length to be?
1. 0.5 m
2. 0.87 m
3. 1 m
4. 2 m
Problems 35 05
39:09, highSchool, numeric, < 1 min, normal.
According to Newtonian mechanics, the
momentum of a bus is p = mv. According
the relativity, it is p = γ mv.
How many times greater the actual momentum of the bus moving at 0.99 c compare
with the momemtum it would have if classical
mechanics were valid? 297 Chapter 39, section 10, Relativistic Energy
Conceptual 12 01
39:10, highSchool, numeric, > 1 min, normal.
Part 1 of 2
According to Einstein’s famous equation
E = mc 2 how much energy is contained in 1 lb of feathers?
Part 2 of 2
What relationship would the above energy E1
and the energy E2 of 1 lb of lead have?
1. E1 > E2
2. E1 < E2
3. E1 = E2
4. Unable to determine
Conceptual 12 02
39:10, highSchool, numeric, < 1 min, normal.
According to Einstein’s famous equation
E = m c2
how much energy is contained in 100 kg of
matter?
Conceptual 12 07
39:10, highSchool, numeric, > 1 min, normal.
Part 1 of 3
In the Sun, 1 g of hydrogen consumed in
nuclear fusion reactions produce 0.9929 g of
helium; the other 0.0071 g of material is converted into other forms of energy.
How much energy does this process produce?
Part 2 of 3
How high could you raise the Mt. Palomar
5m telescope (of mass 450000 kg) with this
energy? 298 Part 3 of 3
If you could convert 1 g of hydrogen into
energy every second through nuclear fusion,
the energy produced would be equivalant to
how many 1gigawatt power plants?
Conceptual 28 12
39:10, highSchool, numeric, < 1 min, normal.
Part 1 of 2
If you were able to extract 100% of the
energy available in 1 kg of hydrogen, how
much energy would you have?
Part 2 of 2
How much energy would be available from
1 kg of uranium if the same 100% eﬃciency
were attained in this extraction?
Figuring Physics 33
39:10, highSchool, multiple choice, > 1 min,
ﬁxed.
Einstein’s celebrated equation, E = m c2
states that energy is equal to the mass of
an object multiplied by the speed of light
squared.
What the equation means is
1. energy and mass both travel at the speed
of light.
2. when mass travels at the speed of light it
becomes pure energy.
3. when mass travels at the speed of light
squared it becomes pure energy.
4. mass and energy are related.
5. (all of these).
6. (none of these).
Problems 35 10
39:10, highSchool, numeric, > 1 min, ﬁxed.
The fractional change of masses to energy in
a ﬁssion reactor is about 0.1uranium that un Chapter 39, section 10, Relativistic Energy
dergoes ﬁssion, how much energy is released?
If energy costs three cents per megajoule,
how much is this energy worth in dollars? 299 Chapter 39, section 11, Mass as a Measure of Energy
Concept 35 35
39:11, highSchool, multiple choice, < 1 min,
ﬁxed.
What does the equation E = m c2 mean?
1. We cannot move faster than the speed of
light.
2. It is a very important clue for makers of
nuclear bombs.
3. Energy and mass are equivalent.
4. Light carries enormous energy. 300 Chapter 39, section 13, Conservation of Relativistic Momentum, Mass, and Energy
Concept 35 28
39:13, highSchool, multiple choice, < 1 min,
ﬁxed.
If a highspeed spaceship appears shrunken
to half its normal length, how does its momentum compare with the classical formula
p = m v?
1. 0.5 m v
2. 0.87 m v
3. m v
4. 2 m v 301 Chapter 39, section 17, General Relativity and Accelerating Reference Frames 302 the same color you send?
Concept 36 12
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
If we witness events taking place on the
moon, where gravitation is weaker than on
Earth, would we expect to see a gravitational
red shift or a gravitational blue shift?
1. Red shift; events on the moon run slower
than on Earth. 1. Yes; the frequency of light does not
change, so the color she received is the same
as the color you sent.
2. No; the frequency of light is increased, so
the color is red shifted.
3. No; the frequency of light is decreased, so
the color is blue shifted.
4. We need to know the exact frequency. 2. Blue shift; events on the moon run faster
than on Earth.
3. It depends on the speed of event.
4. No shift; events run at the same speed on
the moon and Earth.
Concept 36 13
39:17, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 36 19
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Is light emitted from the surface of a massive star redshifted or blueshifted by gravity?
1. Red shifted
2. Blue shifted Armed with highly sensitive detection
equipment, you are in the front of a railroad car that is accelerating forward. Your
friend at the rear of the car shines green light
toward you.
Do you ﬁnd the light to be redshifted (lowered in frequency), blueshifted (increased in
frequency), or neither?
1. red shift
2. blue shift
3. It depends on the speed.
4. no shift
Concept 36 18
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Splitting hairs, if you shine a beam of colored light to a friend above in a high tower,
will the color of light your friend receives be 3. No shift
4. It depends on the mass of star.
Concept 36 20
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
From our frame of reference on Earth,
objects slow to a stop as they approach
black holes in space because time is inﬁnitely
stretched by the strong gravity near the black
hole.
If astronauts accidentally falling into a
black hole tried to signal back to Earth by
ﬂashing a light, what kind of “telescope”
would we need to see the signals?
1. one sensitive to the Xrays
2. one sensitive to the ultra violet light
3. one sensitive to the visible lights Chapter 39, section 17, General Relativity and Accelerating Reference Frames 303 1. Yes.
4. one sensitive to radio waves
2. No.
Concept 36 21
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Would an astronaut falling into a black hole
see the surrounding universe redshifted or
blueshifted? Concept 36 26
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Do binary stars (doublestar systems that
orbit about a common center of mass) radiate
gravitational waves? Why or why not? 1. Red shifted
1. Yes; they are the accelerating masses.
2. Blue shifted
3. No shift
4. It depends on the gravity of the black
hole.
Concept 36 22
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
How can we observe a black hole if neither
matter nor radiation can escape from it?
1. We can observe the radiation from it.
2. We can use Xray telescopes which are
very sensitive to very short wavelengths. 2. Yes; they are more massive than one
star.
3. No; their orbit is not circular.
4. No; radiating gravitational waves is one
characteristic of a single star, not a doublestar system.
Concept 36 28
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Comparing Einstein’s and Newton’s theories of gravitation, can the correspondence
principle be applied?
1. Yes. 3. We can detect its emitted gravitational
radiation.
4. We can observe the gravitational eﬀect of
the black hole on a visible star’s orbit located
near it.
Concept 36 25
39:17, highSchool, multiple choice, < 1 min,
ﬁxed.
In the astronomical triangle, with sides deﬁned by light paths, the sum of the interior
angles is more than 180 degrees.
Is there any astronomical triangle whose
interior angles sum to less than 180 degrees? 2. No. Chapter 40, section 1, The Photon, the Quantum of Light 304 ﬁxed.
Concept 40 1
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What is correct about quantum physics?
1. Quantum physics is characterized by absolute predictability.
2. Quantum physics rules don’t apply for
subatomic particles. What does it mean to say that something
is quantized?
1. It could be regarded as macroscopic particles.
2. It doesn’t have any property of wave.
3. It only has particle properties.
4. It is composed of elementart units. 3. Quantum physics is primarily the physics
know before 1900 that includes the study of
motion according to Newton’s laws and the
study of electromagnetism in accordance with
the laws of Maxwell. Concept 40 30
40:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Quantum physics rules are rules of propability, not certainly. If a particle is smaller than the wavelength
of visible light, with which microscope could
we discern it? Concept 40 19
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The camera that takes photograph of a
woman’s face used ordinary lenses that are
well known to refract waves. Yet the stepbystep formation of the images is evidence of
photons.
Which of the following is not right?
1. Light refracting through the lens system is
understandable via the wave model of light.
2. The arrival of light spot by spot to form
the image is understandable via the particle
model of light. 1. the electron microscope
2. the optical microscope
3. both
4. neither
Concept 40 31
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Would a beam of protons in a “proton microscope” exhibit greater or less diﬀraction
than electrons of the same speed in an electron microscope?
1. greater 3. Single photons only have particle properties whereas light, composed of many photons,
has wave properties. 2. less
3. the same 4. Light has both wave and particle properties.
Concept 40 2
40:01, highSchool, multiple choice, < 1 min, 4. More information is needed.
Concept 40 32
40:01, highSchool, multiple choice, < 1 min, Chapter 40, section 1, The Photon, the Quantum of Light
ﬁxed.
Suppose nature were entirely diﬀerent so
that an inﬁnite number of photons would be
needed to make up even the tiniest amount
of radiant energy, the wavelength of material
particles were zero, light would have no particle properties, and matter would have no wave
properties. This would be the classical world
described by the mechanics of Newton and
the electricity and magnetism of Maxwell.
What would be the value of Planck’s constant for such a world with no quantum effects?
1. extraordinarily large 305 Consider E = h f , the formula of a proton’s energy where f in the formula is a wave
frequency, which of the following is not right?
1. The formula links a particle property (the
photon energy E ) to a wave property, the
frequency f .
2. Since f is a wave frequency, the formula
illustrates that the photon could be regarded
as wave.
3. If h were zero, there would be no quantum
phenomena.
4. The formula illstrates that the photon has
both wave and particle properties. 2. positive
3. negative
4. zero
Concept 40 33
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose you lived in a hypothetical world
where you’d be knocked down by a single photon, where matter would be so wavelike that it
would be fuzzy and hard to grasp, and where
the uncertainty principle would impinge on
simple measurements of position and speed in
a laboratory, making results irreproducible.
In such a world, how would Planck’s constant compare to what it is in reality? Concept 40 41
40:01, highSchool, numeric, < 1 min, ﬁxed.
A typical wavelength of infrared radiation
emitted by your body is 2.5 × 10−5 m.
What is the energy per photon of such radiation?
Concept 40 4
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The frequency of violet light is about twice
that of red light.
How does the energy of a violet photon
compare with the energy of a red photon?
1. twice as energetic as red photons 1. extremely large 2. half as energetic as red photons 2. extremely small 3. the same as red photons 3. equal 4. It requires a casebycase analysis. 4. More information is needed.
Concept 40 3
40:01, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 40 5
40:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following is not right? Chapter 40, section 1, The Photon, the Quantum of Light
1. The energy of a green photon is larger
than that of a red one.
2. The energy of a violet photon is larger
than that of a green one.
3. The wavelength of a red photon is larger
than that of a violet one.
4. The energy of a white photon is larger
than that of a violet one.
Concept 40 6
40:01, highSchool, multiple choice, < 1 min,
ﬁxed. 306 photon jumps from B to A.
Part 2 of 2
Find the wavelength λ3 emitted when the
photon jumps from C to A.
Hewitt CP9 32 E02
40:01, highSchool, multiple choice, > 1 min,
ﬁxed.
Which color of light comes from a greater
energy transition?
1. Red
2. Yellow If a beam of red light and a beam of blue
light have exactly the same energy, which
beam contains the greater number of photons?
1. the beam of red light
2. the beam of blue light
3. The beams have the same number of photons.
4. It requires a casebycase analysis.
Hewitt CP9 30 P01
40:01, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
In the diagram, the energy diﬀerence between states A and B is twice the energy
diﬀerence between states B and C. In a transition (quantum jump) from C to B an electron
emits a photon of wavelength 600 nm.
C
B
A Find the wavelength λ2 emitted when the 3. Green
4. Blue
Holt SF 23A 02
40:01, highSchool, numeric, < 1 min, wordingvariable.
A vibrating massspring system has a frequency of 0.56 Hz.
How much energy of this vibration is carried
away in a onequantum change?
Holt SF 23A 03
40:01, highSchool, numeric, < 1 min, wordingvariable.
A photon in a laboratory experiment has
an energy of 5.0 eV.
What is the frequency of this photon?
Holt SF 23A 04
40:01, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
Radiation emitted from human skin reaches
its peak at λ = 940 µm.
a) What is the frequency of this radiation?
Part 2 of 3
b) What type of electromagnetic waves are Chapter 40, section 1, The Photon, the Quantum of Light 307 these?
1. infrared waves A photon of a certain color of visible light
has 2.9 × 10−19 J of energy.
What color is the light? 2. microwaves
1. Blue
3. radio waves
2. Red
4. visible light
3. White
5. ultraviolet light
4. Yellow
6. x rays
5. None of these
7. gamma rays
Part 3 of 3
c) How much energy is carried by one quantum of these electromagnetic waves?
Holt SF 23Rev 14
40:01, highSchool, numeric, < 1 min, wordingvariable.
A quantum of electromagnetic radiation
has an energy of 2.0 keV.
What is its frequency?
Holt SF 23Rev 15
40:01, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 3
The energy of a photon increases as its
wavelength decreases.
a) What is the energy of a microwave photon with a wavelength of 5.00 cm?
Part 2 of 3
b) What is the energy of a visible photon
with a wavelength of 5.00×10−7 m?
Part 3 of 3
c) What is the energy of an Xray photon
with a wavelength of 5.00 × 10−8 m?
Holt SF 23Rev 45
40:01, highSchool, multiple choice, < 1 min,
normal. Holt SF 23Rev 50
40:01, highSchool, numeric, < 1 min, wordingvariable.
How many photons are emitted every 1.00
s by a 100.0 W sodium lamp if the wavelength
of sodium light is 589.3 nm?
Holt SF 23Rev 51
40:01, highSchool, numeric, < 1 min, wordingvariable.
From the scattering of sunlight, Thomson
found that the classical radius of the electron
is 2.82 × 10−15 m. If sunlight with an intensity of 5.00 × 102 W/m2 falls on a disk with
this radius, estimate the time required to accumulate 1.0 eV of energy. Assume that light
is a classical wave and that the light striking
the disk is completely absorbed.
How does your estimate compare with the
observation that photoelectrons are emitted
within 10−9 s?
Wavelength of a Photon
40:01, highSchool, numeric, < 1 min, normal.
A quantum of electromagnetic radiation
has an energy of 2 keV.
What is its wavelength? The speed of light
is c = 2.99792 × 108 m/s, and Planck’s constant is h = 6.62608 × 10−34 J s. Chapter 40, section 3, Blackbody Radiation and Planck’s Hypothesis
Company distances of two stars
40:03, highSchool, multiple choice, > 1 min,
ﬁxed.
Suppose two stars of the same apparent
brightness are also believed to be the same
size. The spectrum of one star peaks at λ1
whereas that of other peaks at λ2 .
Use Wien’s law λ T = 2.9 × 10−3 mK and
the StefanBoltzman law (L ∝ A T 4 , where
A is the surface area of the star) to estimate
the ratio D2 /D1 , where D1 and D2 are their
respective distances from us. 308 1. No; the ﬁlament will have the same temperature as its environment.
2. No; the ﬁlament will be dark at room
temperature.
3. Yes; the ﬁlament will be at a temperature
that is greater than absolute zero.
4. Yes; the ﬁlament has a smaller heat capacity than its environment.
Concept 30 37
40:03, highSchool, multiple choice, < 1 min,
ﬁxed. D2
1.
=
D1 λ1
λ2 2 D2
2.
=
D1 λ2
λ1 2 D2
=
D1 λ1
λ2 3/2 1. Red D2
=
4.
D1
D2
=
5.
D1
D2
6.
=
D1 λ2
λ1
λ1
λ2
λ2
λ1 3/2 2. White D2
=
7.
D1 λ1
λ2 1/2 3. If we continue heating a piece of initially
roomtemperature metal in a dark room,
what will be its ﬁrst visible color? 3. Violet
4. There will be no color at all. 1/2 D2
λ2
8.
=
D1
λ1
D2
9.
=1
D1
D2
10.
= (λ1 λ2 )1/3
D1
Concept 30 34
40:03, highSchool, multiple choice, < 1 min,
ﬁxed.
We know that a lamp ﬁlament at 2500 K
radiates white light.
Does the lamp ﬁlament also radiate energy
when it is at room temperature? Figuring Physics 13
40:03, highSchool, multiple choice, < 1 min,
ﬁxed.
You’re a consultant to a manufacturer of
space gear that wants to encase instruments
in a covering that will have two properties: (1)
absorb as little energy as possible on the side
of the package facing the sun, and (2) emit
as little energy as possible on the side facing
away from the sun. You should recommend a
covering with
1. the side facing the sun black and the other
side shiny.
2. the side facing the sun shiny and the other
side black.
3. both sides shiny. Chapter 40, section 3, Blackbody Radiation and Planck’s Hypothesis
4. both sides black.
Holt SF 23A 01
40:03, highSchool, numeric, < 1 min, wordingvariable.
Assume that the pendulum of a grandfather
clock acts as one of Planck’s resonators.
If it carries away an energy of 8.1 × 10−15
eV in a one quantum change, what is the
frequency of the pendulum? 309 Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect 310 ﬁxed.
Concept 30 21
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Your friend reasons that if ultraviolet light
can activate the process of ﬂuorescence, infrared light should also. Your friend looks to
you for approval or disapproval of this idea.
What is your position?
1. Your friend is correct; if the intensity of
the infrared light is strong enough, ﬂuorescence will be easily activated.
2. Your friend could be wrong; the energy
of the ultraviolet photon is higher than the
energy of infrared photon, so the ﬂuorescence
activated by the ultraviolet light may not necessarily be activated by the infrared light.
3. It depends; we need to know the intensity
and the duration of the irradiation that will
be used to activate the ﬂuorescence. In the photoelectric eﬀect, does brightness
or frequency determine the kinetic energy of
the ejected electrons? The number of the
ejected electrons?
1. Brightness; brightness.
2. Brightness; frequency.
3. Frequency; brightness.
4. Frequency; frequency.
Concept 40 11
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
A very bright source of red light has much
more energy than a dim source of blue light.
What has no eﬀect in ejecting electrons
from a certain photosensitive surface?
1. Bright source of red light 4. None of these
2. Dim source of blue light
Concept 30 22
40:04, highSchool, multiple choice, < 1 min,
ﬁxed. 3. Equally possible.
4. It requires a casebycase analysis. When ultraviolet light falls on certain dyes,
visible light is emitted.
What will happen when infrared light falls
on these dyes? Concept 40 12
40:04, highSchool, multiple choice, < 1 min,
ﬁxed. 1. Visible light will be emitted with the same
intensity. What is ejected when light strikes a metal
surface? 2. There will be no visible light at all.
3. Ultraviolet light with very low intensity
will be emitted. 1. Electrons
2. Photons
3. Neutrons 4. Infrared light with a shorter wavelength
than the incident light will be emitted.
Concept 40 10
40:04, highSchool, multiple choice, < 1 min, 4. Both electrons and photons
Concept 40 13
40:04, highSchool, multiple choice, < 1 min, Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect 311 ﬁxed.
3. The charge remains the same.
The photoelectric eﬀect is used to open
automatic doors when someone approaches.
The door utilizes a beam of light that continuously shines on a photodetector.
Why does the door open automatically
when you block the beam by walking through
it?
1. The generation of electrons in the photodetector ceases.
2. The generation of protons in the photodetector ceases.
3. The number of protons generated in the
photodetector decreases.
4. The number of electrons generated in the
photodetector increases.
Concept 40 14
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
If you shine an ultraviolet light on the metal
ball of a negatively charged electroscope, what
will happen?
1. The charge increases.
2. The charge decreases.
3. The charge remains the same.
4. It requires a casebycase analysis.
Concept 40 15
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
If you shine an ultraviolet light on the metal
ball of a positively charged electroscope, what
will happen? 4. It depends on a casebycase analysis.
Concept 40 16
40:04, highSchool, multiple choice, > 1 min,
ﬁxed.
What is not correct about the usage of
photoelectric eﬀect?
1. Electric eye: A beam of light is directed
to a photosensitive surface that completes the
path of an electric circuit. When the beam is
interrupted, the circuit is broken. The entire
photoelectric circuit may be used as a switch
for another circuit.
2. Light meter: The variation of photoelectric current with variation in light intensity
activates a galvanometer (or its equivalent),
which is calibrated to show light intensity.
3. Sound track: An optical sound track on
motion picture ﬁlm is a strip of emulsion of
variable density that transmits light of variable intensity onto a photosensitive surface,
which in turn produces an electric current of
the desired variations. This current is ampliﬁed and activates the loudspeaker.
4. Automatic door: The doors utilize a beam
of light that continuously shines on a photodetector. When you block the beam by walking
through it, the current in the photodetector
increases. This change of current then activates the opening of the door.
Concept 40 17
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which aspect of the property of light does
the photoelectric eﬀect support? What about
the interference experiment? 1. The charge increases.
2. The charge decreases. 1. Both support the corpuscular model of
light. Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect 312 Which color do you expect it to be?
2. Both support the wave model of light.
1. red
3. Corpuscular model; wave model
2. blue
4. Wave model; corpuscular model
3. green
Concept 40 18
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider Einstein’s explanation of the photoelectric eﬀect and Young’s explanation of
the doubleslit experiments.
Which is/are correct?
1. Only Einstein’s
2. Only Young’s
3. Both are correct. 4. yellow
Concept 40 8
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Silver bromide is a lightsensitive substance
used in some types of photographic ﬁlm. To
cause exposure of ﬁlm, it must be illuminated
with light having suﬃcient energy to break
apart the molecules. This ﬁlm may be handled without danger of exposure in a darkroom illuminated with a certain light.
Which light? 4. Both are wrong.
1. very bright red light
Concept 40 20
40:04, highSchool, multiple choice, < 1 min,
ﬁxed. 2. very dim blue light
3. very bright blue light Which of the following is NOT evidence of
the wave nature of light?
1. diﬀraction
2. polarization
3. interference
4. photoelectric eﬀect 4. common blue light
Concept 40 9
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Sunburn produces cell damage in the skin.
Which of the following is the most capable
of producing this damage? Concept 40 7
40:04, highSchool, multiple choice, < 1 min,
ﬁxed. 1. ultraviolet radiation One of the technical challenges facing the
original developers of color television was the
design of an image tube (camera) for a certain
color of the image. It’s diﬃcult to ﬁnd a
material that would respond to light of this
color. 3. intense visible radiation 2. visible radiation 4. ultrared radiation
Conceptual 22 Q13
40:04, highSchool, multiple choice, < 1 min, Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect 313 ﬁxed.
Which light photon is more eﬀective at inducing the photoelectric eﬀect than visible
light photons?
1. Ultraviolet light has more energy per photon than visible light. Therefore an ultraviolet
photon is more likely able to give an electron
enough energy to escape a metal surface.
2. Visible light has more energy per photon than ultraviolet light . Therefore a visible
light photon is more likely able to give an
electron enough energy to escape a metal surface.
Hewitt CP9 31 P01
40:04, highSchool, numeric, > 1 min, ﬁxed.
A typical wavelength of infrared radiation
emitted by your body is 2.5 × 10−5 m .
Find the energy per photon of such radiation.
The speed of light is 2.998 × 108 m/s.
Holt SF 23B 01
40:04, highSchool, numeric, < 1 min, wordingvariable. Holt SF 23B 03
40:04, highSchool, numeric, < 1 min, wordingvariable.
Light of frequency 1.00 × 1015 Hz illuminates a sodium surface. The ejected photoelectrons are found to have a maximum kinetic energy of 1.86 eV.
Calculate the work function of sodium.
Holt SF 23B 04
40:04, highSchool, multiple choice, < 1 min,
wordingvariable.
Which of the following metals will exibit
the photoelectric eﬀect when light with a frequency of 7.0 × 1014 Hz frequency is shone on
it?
a. lithium, hft = 2.3eV
b. silver, hft = 4.7eV
c. cesium, hft = 2.14eV
1. Lithium and cesium
2. Lithium
3. Cesium
4. Lithium and silver In the photoelectric eﬀect, it is found that
incident photons with 5.00 eV of energy will
produce electrons with a maximum kinetic
energy of 3.00 eV.
What is the threshold frequency of this material?
Holt SF 23B 02
40:04, highSchool, numeric, > 1 min, ﬁxed. 5. Silver
6. None of these
Holt SF 23Rev 16
40:04, highSchool, numeric, < 1 min, wordingvariable. Part 1 of 2
Light of wavelength 350 nm falls on a potassium surface, and the photoelectrons have a
maximum kinetic energy of 1.3 eV.
a) What is the work function of potassium? Light of frequency 1.5 × 1015 Hz illuminates a piece of tin, and the tin emits photoelectrons with a maximum kinetic energy of
1.2 eV.
What is the threshold frequency of the
metal? Part 2 of 2
b) What is the threshold frequency for potassium? Holt SF 23Rev 17
40:04, highSchool, numeric, > 1 min, wordingvariable. Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect
Part 1 of 2
Light of wavelength 3.0 × 10−7 m shines on
the metals lithium, iron, and mercury, which
have work functions of 2.3 eV, 3.9 eV, and
4.5 eV, respectively.
a) Which of these metals will exhibit the
photoelectric eﬀect?
1. Lithium
2. Iron
3. Mercury
4. Lithium and iron
5. Iron and mercury
6. None of these
Part 2 of 2
b) For those metals that do exhibit the photoelectric eﬀect, what is the maximum kinetic
energy of the photoelectrons?
1. 5.2 eV and 2.4 eV
2. 1.84375 eV and 0.24375 eV
3. 10.1 eV
4. 7.4 eV, 5.0 eV and 2.1 eV
5. None of these
Holt SF 23Rev 18
40:04, highSchool, numeric, < 1 min, wordingvariable.
The threshold frequency of silver is 1.14 ×
10 Hz.
What is the work function of silver?
15 314 speeds ranging up to 460 km/s when light
with a wavelength of λ = 625 nm is used.
a) What is the work function of this surface?
Part 2 of 2
b) What is the threshold frequency for this
surface?
Holt SF 23Rev 46
40:04, highSchool, numeric, < 1 min, wordingvariable.
A light source of wavelength λ illuminates a
metal and ejects photoelectrons with a maximum kinetic energy of 1.00 eV. A second light
1
source of wavelength λ ejects photoelectrons
2
with a maximum kinetic energy of 4.00 eV.
What is the work function of the metal?
Holt SF 23Rev 47
40:04, highSchool, numeric, < 1 min, wordingvariable.
Given: g = 9.81 m/s2 .
A 0.50 kg mass falls from a height of 3.0
m. If all of the energy of this mass could
be converted to visible light of wavelength
5.0 × 10−7 m, how many photons would be
produced?
Holt SF 23Rev 48
40:04, highSchool, numeric, > 1 min, wordingvariable.
Red light (λ = 670.0 nm) produces photoelectrons from a certain material. Green
light (λ = 520.0 nm) produces photoelectrons
from the same material with 1.50 times the
previous maximum kinetic energy.
What is the material’s work function? Holt SF 23Rev 43
40:04, highSchool, numeric, < 1 min, normal. Holt SF 23Rev 52
40:04, highSchool, numeric, > 1 min, wordingvariable. Part 1 of 2
Electrons are ejected from a surface with Ultraviolet light is incident normally on the
surface of a substance that has a work func Chapter 40, section 4, Light Quantization and the Photoelectric Eﬀect
tion of 3.44 eV. The incident light has an
intensity of 0.055 W/m2 , and the electrons
are photoelectrically emitted with a maximum speed of 5.2×105 m/s.
Assuming that all of the photons are absorbed, how many electrons are emitted from
a square centimeter of the surface every 1.0
s?
Modern Physics
40:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Choose two topics below which were important in the development of quantum physics.
a) photoelectric eﬀect
b) Bohr’s atomic model
c) relativity
d) Hall eﬀect
e) Maxwell equations 1. a and b
2. a and c
3. a and d
4. a and e
5. b and e
6. b and c
7. b and d
8. c and d
9. c and e
10. d and e 315 Chapter 40, section 5, The Compton Eﬀect
Concept 40 24
40:05, highSchool, multiple choice, < 1 min,
ﬁxed.
When a photon hits an electron and gives it
energy, what happens to the frequency of the
photon after bouncing from the electron?
1. The frequency increases.
2. The frequency decreases.
3. The frequency remains the same.
4. It requires a casebycase analysis. 316 Chapter 40, section 6, ParticleWave Complementarity, Duality: Double Slits
Concept 40 21
40:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Light has been argued as being a wave and
then a particle, and back again.
Which of the following is right?
1. Light’s true nature is as a particle.
2. Light’s true nature is as a wave.
3. Light’s true nature lies somewhere in between wave and particle models.
4. Light’s true nature is waveparticle duality.
Concept 40 22
40:06, highSchool, multiple choice, < 1 min,
ﬁxed.
What laboratory device utilizes the wave
nature of electrons?
1. optical telescope
2. ammeter
3. electron microscope
4. thermometer
Hewitt CP9 31 R11
40:06, highSchool, multiple choice, < 1 min,
ﬁxed.
What evidence can you cite for the particle
nature of light?
1. Photoelectric eﬀect of light
2. Refraction phenomenon of light
3. Diﬀraction phenomenon of light
4. The many colors of light manifests the
particle nature of light. 5. None of these 317 Chapter 40, section 7, Eﬀect of Gravity on Light
Concept 36 23
40:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Should it be possible in principle for a photon to circle a star?
1. Yes, if the star is massive enough to make
light follow a circular path.
2. Yes, if the star rotates very fast to make
light follow a circular path.
3. No; photons travel only in straight
paths. 318 Chapter 41, section 1, The Atomic Nature of Matter 319 Concept 41 11
41:01, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 41 28
41:01, highSchool, multiple choice, < 1 min,
ﬁxed. Is Brownian motion apparent for microscopic or macroscopic particles? Helium is an inert gas, meaning it doesn’t
readily combine with other elements.
Which of the following elements would you
expect to also be an inert gas? 1. Brownian motion is apparent only for
microscopic particles. 1. hydrogen
2. Brownian motion is apparent only for
macroscopic particles.
3. Brownian motion is apparent both for
microscopic and macroscopic particles. 2. carbon
3. nitrogen
4. oxygen 4. It depends on a casebycase analysis.
5. neon
Concept 41 12
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Are atoms visible with electron microscopes
or optical microscopes?
1. only with electron microscopes
2. only with optical microscopes
3. with both electron and optical microscopes Concept 41 30
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following elements would you
pedict to have properties most like those of
silicon?
1. aluminum
2. phosphorus
3. germanium 4. with neither microscope
4. radium
Concept 41 20
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A tree is composed mainly of carbon.
Where does it get this carbon?
1. from sunshine
2. from soil
3. from water
4. from carbon dioxide in the air Concept 41 33
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The atoms that compose your body are
mostly empty space, and structures such as
the chair you’re sitting on are composed of
atoms that are also mostly empty space.
Why don’t you fall through the chair?
1. Macroscopic matter is too big to get
through the microscopic empty space. Chapter 41, section 1, The Atomic Nature of Matter
2. The process of falling through the chair
takes so long time that we can hardly observe
it.
3. The protons are tightly bound. 320 2. liquid
3. equally strong
4. It requires a casebycase analysis. 4. The electrical repulsion between atoms
keeps us from falling through our chairs. Concept 41 45
41:01, highSchool, numeric, < 1 min, ﬁxed. Concept 41 3
41:01, highSchool, multiple choice, < 1 min,
ﬁxed. Part 1 of 3
The diameter of an atom is about 1.0 ×
10−10 meter.
How many atoms make a line a millionth of
a meter long? A cat strolls across your backyard. An hour
later a dog with his nose to the ground follows
the trail of the cat.
Explain this occurrence from a molecular
point of view.
1. The movement of the cat speed up the
average speed of molecules of the air along its
trail. The dog follows the trail by the variance
of temperature.
2. The movement of the cat takes away some
molecules and atoms of the grass along its
trail, so the dog follows the trail by the density
of the grass.
3. The cat leaves a trail of molecules and
atoms on the grass. These in turn leave the
grass and mix with the air, where they enter
the dog’s nose, activating its sense of smell.
4. The cat leaves a trail of molecules and
atoms on the grass, which changes the density
of molecules of the grass. The dog follows the
trail by the density of the grass. Part 2 of 3
How many atoms cover a square a millionth
of a meter on a side?
Part 3 of 3
How many atoms ﬁll a cube a millionth of a
meter on a side?
Concept 41 6
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Which are older, the atoms in the body of
an elderly person or those in the body of a
baby?
1. an elderly person
2. a baby
3. of equal age
4. It requires a casebycase analysis. Concept 41 35
41:01, highSchool, multiple choice, < 1 min,
ﬁxed. Concept 41 7
41:01, highSchool, multiple choice, < 1 min,
ﬁxed. If you have a solid and a liquid at room
temperature, which has stronger interatomic
forces? Where were the atoms that make up a newborn “manufactured”? 1. solid 1. in the mother’s body
2. explosions of ancient stars Chapter 41, section 1, The Atomic Nature of Matter 321 particles?
3. a chemical reaction
1. collisions among gas molecules
4. Unable to determine
Concept 41 8
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A class of meteorites called chondrites contains a relative abundance of elements identical to the relative abundance observed in the
sun (except for the volatile gases hydrogen
and helium).
What does this scientiﬁc ﬁnding suggest
about the origin of the solar system?
1. The entire solar system probably had a
common origin.
2. It took millions of years for most of the
solar system to appear after the ﬁrst particles
appeared.
3. No conclusion can be drawn.
4. Attempting to correlate meteorite composition and the origin of the solar system is
bad science. 2. collisions of gas molecules with the dust
particles
3. collisions among dust particles
Conceptual 21 Q03
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Rutherford’s experiment involved ﬁring
nucleussized bullets at atoms of gold. He
found that one atom in 1000 bounced backward.
How could the experiment have turned out
if the atoms were completely uniform in mass?
1. If the atoms were uniform in mass, the
‘bullets’ would all have done the same thing.
2. If the atoms were not uniform then mostly
may have gone through, coming out on the
other side with much lower speed.
3. Both of these
4. None of these Conceptual 09 Q2
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
A carbon atom and an iron atom are moving in the same speed.
Which atom has more kinetic energy?
1. The carbon atom
2. The iron atom
3. They have the same kinetic energy.
Conceptual 09 Q8
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What causes the Brownian motion of dust Conceptual 21 Q04
41:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Advertisers often describe improvements in
their products as a “quantum leap.”
Is this an appropriate use of the term?
I) A quantum leap is a jump with no stops
in between.
II) A quantum leap is an appropriate analog if the product make a signiﬁcant improvement.
III) A quantum leap is not an appropriate
analog if the product make a signiﬁcant
improvement.
1. I only Chapter 41, section 1, The Atomic Nature of Matter
2. II only
3. III only
4. I and II only
5. I and III only
Part 2 of 2
How big is a quantum leap?
1. very small
2. very big
3. smaller than an atom
4. Cannot be determined 322 Chapter 41, section 2, The Composition of Atoms 323 2. adding one proton to each gold nucleus
Concept 41 10
41:02, highSchool, multiple choice, < 1 min,
ﬁxed. 3. equally valuable
4. It requires a casebycase analysis. Can two diﬀerent elements contain the
same number of protons or neutrons?
1. the same number of protons but not the
same number of neutrons
2. the same number of neutrons but not the
same number of protons
3. the same number of both neutrons and
protons Concept 41 23
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
If two protons and two neutrons are removed from the nucleus of an oxygen atom,
what nucleus remains?
1. original oxygen
2. an isotope of oxygen 4. neither the same number of neutrons nor
of protons
Concept 41 16
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
The atomic masses of two isotopes of cobalt
are 59 and 60.
How many protons, neutrons and orbiting
electrons are in each when the isotopes are
electrically neutral? 3. nitrogen
4. carbon
Concept 41 24
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What element results if you add a pair of
protons to the nucleus of mercury?
1. original mercury 1. Co59: 32, 27, 59; Co60: 33, 27, 60.
2. an isotope of mercury
2. Co59: 27, 59, 59; Co60: 27, 60, 60.
3. thallium
3. Co59: 27, 59, 27; Co69: 27, 60, 27.
4. lead
4. Co59: 27, 32, 27; Co60: 27, 33, 27.
5. platinum
Concept 41 22
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Which would be the more valued result:
taking one proton from each nucleus in a sample of gold or adding one proton to each gold
nucleus?
1. taking one proton from each gold nucleus Concept 41 25
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What element results if two protons and
two neutrons are ejected from a radium nucleus?
1. original radium Chapter 41, section 2, The Composition of Atoms 324 2. an isotope of radium
3. polonium
4. radon
5. thorium
6. uranium Carbon, with a halffull outer shell of electrons, readily shares its electrons with other
atoms and forms a vast number of molecules,
many of which are the organic molecules that
form the backbone of living matter.
Looking at the periodic table, which element might play a role like carbon in life
forms on some other planet? Concept 41 26
41:02, highSchool, multiple choice, < 1 min,
ﬁxed. 1. hydrogen You could swallow a capsule of germanium
without ill eﬀect, but if a proton were added
to each of the germanium nuclei, why would
you not want to swallow the capsule? 3. oxygen 2. carbon 4. silicon
5. aluminum 1. Protons (the hydrogen atoms) are toxic
to human body.
2. Germanium atoms, when combined with
hydrogen atoms, are toxic to human body.
3. Arsenic atoms are toxic to human body.
4. Adding a proton creates a heavy metal,
which is toxic. Concept 41 32
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Which contributes more to an atom’s mass:
electrons or protons? Which contributes more
to an atom’s size?
1. protons; electrons Concept 41 29
41:02, highSchool, multiple choice, < 1 min,
ﬁxed. 2. protons; protons What element results if one of the neutrons
in a nitrogen nucleus is converted by radioactive decay into a proton? 4. electrons; electrons 1. original nitrogen
2. an isotope of nitrogen
3. carbon 3. electrons; protons Conceptual 21 Q05
41:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What can be said about the Rutherford
model of an atom based on Newton’s laws of
motion, the laws of thermodynamics, and the
nature of electromagnetic radiation? 4. oxygen
Concept 41 31
41:02, highSchool, multiple choice, < 1 min,
ﬁxed. 1. The electrons are accelerating, so they
would be giving oﬀ energy.
2. Continuous source of energy must be sup Chapter 41, section 2, The Composition of Atoms 325 plied to the atom.
3. Rutherford model of the atom could not
work
4. All of these
5. None of these
Hewitt CP9 32 E03
41:02, highSchool, numeric, > 1 min, ﬁxed.
How does Rutherford’s model of the atom
account for the backscattering of alpha particles directed at the gold leaf?
1. A gold nucleus is positively charged and
so is an alpha particle.
2. The nucleus is heavy and so is an alpha
particle.
3. There is a dense concentration of positive
charge and mass in the nucleus.
4. Negative charge of an electron is spread
throughout the volume of the atom.
Hewitt CP9 32 E04
41:02, highSchool, multiple choice, > 1 min,
ﬁxed.
At the time of Rutherford’s gold leaf experiment, scientists knew that negatively
charged electrons existed within the atom,
but they did not know where the positive
charge resided.
What information about the positive
charge was provided by Rutherford’s experiment?
1. The positive charge can freely move
within the atom.
2. The positive charge must be concentrated
in a small core (the atomic nucleus).
3. The positive charge is spread throughout
the atom. 4. There is no positive charge associated
with an atom. Chapter 41, section 3, Molecules
Concept 11 01
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How many individual atoms are in a water
molecule? 326 41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
If no molecules in a body could escape,
would the body have any odor?
1. Yes; the odor is composed of waves radiated by the body. 1. three: one hydrogen and two oxygen
2. two: both hydrogen 2. Yes; odor has nothing to do with
molecules. 3. three: one oxygen and two carbon 3. Yes, but the odor would be diﬀerent. 4. three: one oxygen and two hydrogen 4. No 5. two: one oxygen and one hydrogen
6. It depends on the state of the water
molecule.
Concept 11 02
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
When a container of gas is heated, what
happens to the average speed of its molecules? Concept 41 15
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
How many atoms are in a molecule of
ethanol?
1. six
2. three
3. two 1. decreases
4. nine
2. increases
5. ten
3. No change
4. It cannot be determined without a direct
measurement.
Concept 11 41
41:03, highSchool, multiple choice, < 1 min,
normal.
During a certain thermodynamic process a
sample of gas expands and cools, reducing its
internal energy by 3000 J, while no heat is
added or taken away.
How much work is done during this process?
Concept 11 4 Concept 41 19
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
Gasoline contains only hydrogen and carbon atoms. Yet nitrogen oxide and nitrogen
dioxide are produced when gasoline burns.
What is the source of the nitrogen atoms?
1. created from the hydrogen atoms of gasoline by burning
2. created from the carbon atoms of gasoline
by burning
3. created from the interaction of the carbon Chapter 41, section 3, Molecules 327 and hydrogen atoms of gasoline by burning
4. the air
Concept 41 27
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
What results when water is chemically decomposed?
1. vapor
2. mixture of water and vapor Concept 41 43
41:03, highSchool, numeric, < 1 min, normal.
Gas A is composed of diatomic molecules
of a pure element. Gas B is composed of
monatomic molecules of another pure element. Gas A has 3 times the mass of an
equal volume of gas B at the same temperature and pressure.
How do the atomic masses of elements A
and B compare?
Concept 41 44
41:03, highSchool, numeric, < 1 min, ﬁxed. 3. hydrogen and oxygen
4. It requires a casebycase analysis.
Concept 41 34
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
50 cubic centimeters of alcohol are mixed
with 50 cubic centimeters of water.
Why is the volume of the mixture is only 98
cubic centimeters?
1. Some alcohol evaporates.
2. The process of mixing releases heat.
3. Some water vaporizes.
4. The water and alcohol molecules ﬁt into
one another.
Concept 41 41
41:03, highSchool, numeric, < 1 min, normal.
How many grams of oxygen are in 18 g of
water?
Concept 41 42
41:03, highSchool, numeric, < 1 min, normal.
How many grams of hydrogen are in 16 g of
methane gas which has a chemical formula of
CH4 ? A teaspoon of an organic oil dropped on the
surface of a quiet pond spreads out to cover
almost an acre. The oil ﬁlm has a thickness
equal to the size of a molecule. In the lab
when you drop 0.001 milliliter of the organic
oil on the still surface of water, you ﬁnd that it
spreads to cover an area of 1.0 square meter.
If the layer is one molecule thick, what is
the size of a single molecule?
Concept 41 46
41:03, highSchool, numeric, < 1 min, ﬁxed.
There are approximately 1 × 1023 water
molecules in a thimbleful of water and 1 ×
1046 water molecules in the Earth’s oceans.
Suppose that Columbus threw a thimbleful
of water into the ocean and that these water
molecules have by now mixed uniformly with
all the water molecules in the oceans.
If you dip a sample thimbleful of water
from anywhere in the ocean, how many of the
molecules from Columbus’s thimble are you
likely to scoop up?
Concept 41 47
41:03, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
There are approximately 1 × 1022 molecules
in a single mediumsized breath of air and approximately 1 × 1044 molecules in the atmosphere of the whole world. Chapter 41, section 3, Molecules
How many breaths of air are in the world’s
atmosphere? 328 massive?
1. The C60 atom Part 2 of 2
If all the molecules from Julius Caesar’s last
dying breath are now thoroughly mixed in the
atmosphere, how many of these on the average
do we inhale with each single breath?
Concept 41 48
41:03, highSchool, numeric, < 1 min, ﬁxed.
Assume that the present world population
of about 6 × 109 people is about 1/20 the
number of people who ever lived on Earth.
How does the number of people who ever
lived compare to 1 × 1022 , the number of air
molecules in a single breath?
Concept 41 5
41:03, highSchool, multiple choice, < 1 min,
ﬁxed.
The average speed of a perfume vapor
molecule at room temperature may be about
300 m/s, but the speed at which the scent
travels across the room is much less. Why?
1. Vapor molecules travel slower than air
molecules.
2. Vapors move randomly.
3. There are many collisions with other
molecules in the air.
4. Scent will actually travel across a room at
almost 300 m/s.
Conceptual 09 Q3
41:03, highSchool, numeric, > 1 min, ﬁxed.
Fullerenes are large molecules of carbon
containing at least 60 carbon atoms. Discovered in 1985, fullerenes take a roughly
spherical shape, with the carbon atoms arranged in such a way to make them look like
soccer balls.
Is a C60 molecule or a single gold atom more 2. The gold atom
3. A C60 atom is as massive as a gold
atom. Chapter 41, section 4, The Bohr Atom
Concept 30 06
41:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why doesn’t a neon sign ﬁnally “run out”
of excited atoms and produce dimmer and
dimmer light?
1. There are numerous excited atoms in a
neon sign; it takes a very long time for them
to be exhausted.
2. Exhausted atoms will be reexcited by the
energy source and emit light again.
3. The brightness of light is not determined
by the number of excited atoms but by the
energy diﬀerence between the excited atoms
and the unexcited atoms. 329 2. six; level 4 to level 1 transition; level 4 to
level 3 transition.
3. three; level 4 to level 1 transition; level 4
to level 3 transition.
4. three; level 2 to level 1 transition; level 4
to level 3 transition.
Part 2 of 3
An electron deexcites from the fourth quantum level to the third and then directly to the
ground state. Two photons are emitted.
How does the sum of their frequencies compare to the frequency of the single photon
that would be emitted by deexcitation from
the fourth level directly to the ground state?
1. The sum is larger than the frequency of
the single photon. 4. None of these
Concept 30 43
41:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 3
Consider just four of the energy levels in a
certain atom, as shown in the diagram below.
n=4
n=3 1. The sum is equal to the frequency of the
single photon.
1. The sum is smaller than the frequency of
the single photon.
4. None of these
Part 3 of 3
Suppose the four energy levels were somehow
evenly spaced.
How many spectral lines would result? n=2
1. six
2. four
n=1 3. ﬁve How many spectral lines will result from
all possible transitions among these levels?
Which transition corresponds to the highestfrequency light emitted? Which transition
corresponds to the lowestfrequency? 4. three
Concept 41 4
41:04, highSchool, multiple choice, < 1 min,
ﬁxed. 1. three; level 4 to level 3 transition; level 2
to level 1 transition. If no molecules in a body could escape,
would the body have any odor? Chapter 41, section 4, The Bohr Atom
1. Yes; odor has nothing with molecules that
could escape from the body itself. 4. 2.90933 × 1016 Hz 2. Yes; bodies change the property of the
molecules around them diﬀerently. We can
detect the odor of a body when the changed
molecules enter our noses. 330 6. 2.03653 × 1015 Hz 3. No; a body has odor only if some of its
molecules enter a nose.
4. It requires a casebycase analysis.
Conceptual 21 Q06
41:04, highSchool, multiple choice, < 1 min,
ﬁxed.
When you shine invisible ultraviolet light
(black light) on certain objects, they glow
with brilliant colors.
Explain this behavior in terms of the Bohr
atom.
1. UV light excites an electron in the atom
to a higher energy level. 5. 7.27334 × 1015 Hz 7. 3.63667 × 1014 Hz
8. 3.63667 × 1016 Hz
9. 9.09167 × 1015 Hz
10. 2.54567 × 1015 Hz
Hewitt CP9 32 E06
41:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does classical physics predict that
atoms should collapse?
1. Classical physics was not based on experiments.
2. Classical physics predicts the future of
the atomic world. 2. When electron moves down to a lower
energy level it stops at several intermediate
levels. 3. Classically an electron is attracted to a
nucleus and eventually should fall on it. 3. A photon of visible light is emitted for
each jump to the lower level. 4. Classically an electron accelerating
around its orbit should emit radiation. 4. All of these
5. None of these
Frequency of a Lyman line
41:04, highSchool, numeric, > 1 min, ﬁxed.
Determine the frequency of the second Lyman line, the transition from n = 3 to n = 1.
1. 2.90933 × 1015 Hz
2. 3.63667 × 1015 Hz
3. 2.90933 × 1014 Hz Hewitt CP9 32 E07
41:04, highSchool, multiple choice, < 1 min,
ﬁxed.
If an electron in a hydrogen atom obeyed
classical mechanics instead of quantum mechanics, what kind of spectrum would it emit?
1. line spectrum
2. partially line and partially continuous
spectrum
3. continuous spectrum Chapter 41, section 4, The Bohr Atom
4. It wouldn’t emit any spectrum.
Hewitt CP9 32 E10
41:04, highSchool, multiple choice, < 1 min,
ﬁxed.
How can elements with low atomic numbers
have so many spectral lines?
1. Electrons can be boosted to many energy
levels, thus making many diﬀerent transitions
to ground level and levels between.
2. Elements with low atomic numbers have
small masses.
3. Elements with low atomic numbers have
many free electrons.
4. Elements with low atomic numbers usually don’t react chemically with other elements. 331 Chapter 42, section 1, de Broglie Waves 332 ﬁxed.
Concept 40 25
42:01, highSchool, multiple choice, < 1 min,
ﬁxed.
If a proton and an electron have identical
speed, which has the longer wavelength? We don’t notice the wavelength of moving
matter in our ordinary experience.
Which of the following is right?
1. The wavelength is extraordinarily large. 1. the proton 2. The wavelength is extraordinarily small. 2. the electron 3. The wavelength could be either extraordinarily large or small. 3. They have the same wavelength.
4. The wavelength is ordinary.
4. More information is needed.
Concept 40 26
42:01, highSchool, multiple choice, < 1 min,
ﬁxed.
One electron travels twice as fast as another.
Which has longer wavelength? Concept 40 29
42:01, highSchool, multiple choice, < 1 min,
ﬁxed.
If a cannonball and a BB have the same
speed, which has the longer wavelength?
1. The cannonball 1. The faster one 2. The BB 2. The slower one 3. The two have the same wavelength. 3. The two have the same wavelength. 4. More information is needed. 4. More information is needed.
Concept 40 27
42:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What happens to the de Broglie wavelength
of a proton as its velocity increases?
1. Increases
2. Decreases
3. Remains the same
4. More information is needed.
Concept 40 28
42:01, highSchool, multiple choice, < 1 min, Concept 40 42
42:01, highSchool, numeric, < 1 min, normal.
What is the de Broglie wavelength of an
electron that strikes the back of the face of a
1
TV screen at
the speed of light?
10
Concept 40 43
42:01, highSchool, numeric, < 1 min, ﬁxed.
You decide to roll a 0.1 kg ball across the
ﬂoor so slowly that it will have a small momentum and a large de Broglie wavelength.
If you roll it at 0.001 m/s, what will its
wavelength be?
Conceptual 22 Q09
42:01, highSchool, multiple choice, < 1 min,
ﬁxed. Chapter 42, section 1, de Broglie Waves
A hydrogen atom and a uranium atom are
moving at the same speed.
Which one has the longer wavelength?
1. hydrogen
2. uranium 333 42:01, highSchool, numeric, < 1 min, wordingvariable.
If the de Broglie wavelength of an electron is
equal to 5.00 × 10−7 m, how fast is the electron
moving?
The mass of an electron is 9.10939 ×
−31
10
kg and Planck’s constant is 6.63×10−34
J/s. 3. same for both
Conceptual 22 Q10
42:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
An electron and a proton are traveling at
the same speed.
Which one has more momentum? Holt SF 23C 03
42:01, highSchool, numeric, < 1 min, wordingvariable.
How fast would one have to throw a 0.15 kg
baseball if it were to have a wavelength equal
to 5.00 × 10−7 m?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23C 04
42:01, highSchool, numeric, < 1 min, wordingvariable. 1. Electron
2. Proton
Part 2 of 2
Which one has a longer wavelength?
1. Electron What is the de Broglie wavelength of a
1375 kg car traveling at 43 km/h?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23C 05
42:01, highSchool, numeric, < 1 min, wordingvariable. 2. Proton
Hewitt CP9 31 P02
42:01, highSchool, numeric, > 1 min, ﬁxed.
What is the de Brogile wavelength of an
electron that strikes the back of the face of a
TV screen at 0.1 the speed of light?
The speed of light is 2.998 × 108 m/s.
Holt SF 23C 01
42:01, highSchool, numeric, < 1 min, wordingvariable.
With what speed would a 50.0 g rock have
to be thrown if it were to have a wavelength
of 3.32 × 10−34 m?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23C 02 A bacterium moving across a petri dish
at 3.5 µm/s has a de Broglie wavelength of
1.9 × 10−13 m.
Planck’s constant is 6.63 × 10−34 J · s.
What is the bacterium’s mass?
Holt SF 23Rev 39
42:01, highSchool, numeric, < 1 min, normal.
How fast must an electron move if it is to
have a de Broglie wavelength of 5.2 × 10−11 m?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23Rev 40
42:01, highSchool, numeric, < 1 min, normal.
Calculate the de Broglie wavelength of
0.15 kg baseball moving at 45 m/s? Chapter 42, section 1, de Broglie Waves
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23Rev 41
42:01, highSchool, numeric, < 1 min, wordingvariable.
What is the speed of a proton with a de
Broglie wavelength of 4.00 × 10−14 m?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23Rev 42
42:01, highSchool, numeric, < 1 min, normal.
A mosquito moving at 12 m/s has a de
Broglie wavelength of 5.5 × 10−30 m.
Planck’s constant is 6.63 × 10−34 J · s.
What is the mass of this mosquito?
Holt SF 23Rev 44
42:01, highSchool, numeric, < 1 min, wordingvariable.
What is the de Broglie wavelength of a
proton traveling at 1.0 × 107 m/s?
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23Rev 49
42:01, highSchool, numeric, < 1 min, wordingvariable.
Find the de Broglie wavelength of a ball
with a mass of 0.200 kg just before it strikes
the Earth after it has been dropped from a
building 50.0 m tall.
Planck’s constant is 6.63 × 10−34 J · s.
Holt SF 23Rev 53
42:01, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
The wave nature of electrons makes an electron microscope, which uses electrons rather
than light, possible. The resolving power of
any microscope is approximately equal to the
wavelength used. A resolution of approximately 1.0 × 10−11 m would be required in
order to ”see” an atom.
Planck’s constant is 6.63 × 10−34 J · s.
a) If electrons were used, what minimum ki 334 netic energy of the electrons (in eV) would be
required to obtain this degree of resolution?
Part 2 of 2
b) If photons were used, what minimum photon energy would be required? Chapter 42, section 5, The Heisenberg Uncertainty Principle
Uncert in Posit for Giancoli
42:05, highSchool, numeric, < 1 min, normal.
This problem is for PHY302L only,
using Giancoli’s book.
A 50 g ball moves at 30 m/s. If its speed is
measured to an accuracy of 0.1%, what is the
minimum uncertainty in its position?
Uncert of Momentum for Giancoli
42:05, highSchool, numeric, < 1 min, normal.
This problem is for PHY302L only,
using Giancoli’s book.
Assume we can localize a particle to an
uncertainty of 0.5 nm. What will be the resulting minimum uncertainty in the particle’s
momentum? 335 Chapter 43, section 14, Observables and Operators
1. No
Conceptual 22 Q02
43:14, highSchool, multiple choice, < 1 min,
wordingvariable. Wave Function Your friend, John and Jean, are both driving from Chicago to Des Moines. You know
that Jean is on the road, and you know when
she left Chicago. On the other hand, you
know that John is on the road, but you have
no idea when he left. 2
1 Chicago Des Moines Which one is for John ?
1. 2
2. 1
Conceptual 22 Q06
43:14, highSchool, multiple choice, < 1 min,
ﬁxed.
Chaotic systems are, for all practical purposes, unpredictable.
How does this sort of unpredictability diﬀer
from that associated with quantum mechanics?
1. Classical chaotic systems are deterministic; quantum systems are not deterministic.
2. Quantum systems are deterministic; classical chaotic systems are not deterministic.
Conceptual 22 Q07
43:14, highSchool, multiple choice, < 1 min,
ﬁxed.
If you threw baseballs through a large twoslit apparatus, would you produce a diﬀraction pattern? 2. Yes 336 Chapter 45, section 2, Particle in a ThreeDimensional Box
Angular Momentum 26
45:02, highSchool, numeric, < 1 min, ﬁxed.
What are the total angular momentum values that are obtained in the addition of l = 2
and s = 1/2 ?
5
1. ,
2
7
2. ,
2
5
3. ,
2
3
4. ,
2 3
2
5
2
31
,
22
1
2 Angular Momentum 26b
45:02, highSchool, numeric, < 1 min, ﬁxed.
What are the total angular momentum values that are obtained in the addition of l = 1
and s = 3/2 ?
7
1. ,
2
7
2. ,
2
5
3. ,
2
3
4. ,
2 5
,
2
5
2
3
,
2
1
2 3
2 1
2 Angular Momentum 26c
45:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What are the total angular momentum
values that are obtained in the addition of
l = 1/2 and s = 1/2 ?
5
1. ,
2
3
2. ,
2
1
3. ,
2 3
2
1
2
0 4. 1, 0 337 Chapter 45, section 4, Space Quantization
Angular Momentum 27
45:04, highSchool, numeric, < 1 min, ﬁxed.
What angularmomentum states result
when angular momentum l1 = 3 is added
to angular momentum l2 = 2?
Check that the degeneracies 2l + 1 for these
states add up to the total number of states
(2 l1 + 1) (2 l2 + 1).
Angular Momentum 31
45:04, highSchool, numeric, < 1 min, normal.
The magnetic moment associated with the
orbital motion of an atomic electron has magnitude 3.20933 × 10−23 C · m2 /sA m2 .
What is the angularmomentum quantum
number of the electron orbit? 338 Chapter 46, section 2, Atomic Spectra 339 of the planets.
Conceptual 21 05
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
If a oneelectron atom can occupy any of
four diﬀerent energy levels, how many lines
might appear in that atom’s spectrum?
1. six 2. By analyzing the spectrum of the atmosphere of the planets.
3. By analyzing the atoms that composed
the planets.
4. By analyzing the molecules that compose
the planets. 2. four 5. All of these 3. ﬁve 6. None of these 4. seven
5. None of these
Conceptual 21 Q08
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Space probes often carry compact spectrometers among their scientiﬁc hardware.
What kind of spectroscopy might scientists
use to determine the surface composition of
the cold, outer planets that orbit the Sun? Conceptual 21 Q09
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose a particular atom has only two
allowable electron orbits.
How many diﬀerent wavelength photons
(spectral lines) would result from all electron
transitions in this atom?
1. one
2. two
3. three 1. Each atom of molecule gives oﬀ a set of
photons when it is excited.
2. Excited photons changes chemical property.
3. The photons emit light energy when they
change the energy levels.
4. All of these
5. None of these
Part 2 of 2
How might they use spectroscopy to determine the atmospheric composition of these
planets?
1. By analyzing the spectrum of the surface 4. four
5. None of these
Conceptual 21 Q15
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
In his famous experiment, Rutherford ﬁred
alpha particles at a thin gold ﬁlm. Most of the
alpha particles went through the ﬁrm and a
very few bounced back. Suppose instead that
about onehalf the alpha particles bounced
back and onehalf went through.
How would this have changed his conclusion
about the structure of the atom?
1. Atom is mostly empty space. Chapter 46, section 2, Atomic Spectra 340 2. The laser produce beam of light.
2. Nucleus is about 1/2 the size of the
atom. 3. Both of these 3. The atom has no nucleus. 4. More information is needed. 4. The nucleus covers the entire atom. 5. None of these 5. None of these
Conceptual 21 Q16
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
In the process of ﬂuorescence, an atom absorbs a photon of ultraviolet light and emits
two or more photons of visible light.
Is the reverse process possible? (That is, is
it possible for an atom to absorb a photon of
visible light and emit photons of ultraviolet
light?)
1. Yes; ultraviolet photons have less energy
than visible light.
2. No; ultraviolet photons have more energy
than the visible light.
3. Yes; the energy is equal;
4. More information is needed.
5. None of these
Conceptual 21 Q17
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
A 100watt bulb becomes warm and glows
brightly enough to light a small room. On the
other hand, a 100watt laser can cut holes in
steel and would not be eﬀective at lighting a
small room.
What is true about the light coming from
these two sources that accounts for these differences?
1. The light bulb illuminate a room. Hewitt CP9 32 R08
46:02, highSchool, multiple choice, < 1 min,
ﬁxed.
What is true about the light emitted by an
atom?
1. The emitted photon’s frequency is the
classic frequency at which an electron vibrates.
2. An electron accelerating around its orbit
continuously emits radiation.
3. The energy of the emitted photon is equal
to the diﬀerence in energy between the two
orbits.
4. None of these Chapter 46, section 5, The SpinOrbit Interaction and Other Magnetic Eﬀects
Complex Atoms and Molecules 1
46:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Write the conﬁguration for the ground state
of the magnesium atom(Z = 12).
If the closed shells always have Ltot =
Stot = 0, what is the total angular momentum of magnesium?
1. 1s2 2s2 2p6 3s2 , Jtot = 1/2
2. 1s2 2s2 2p5 3s3 , Jtot = 1
3. 1s2 2s2 2p5 3s3 , Jtot = 1/2
4. 1s2 2s2 2p6 3s2 , Jtot = 0
Complex Atoms and Molecules 2
46:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider the ground state of the silicon
atom (Z = 14).
What is the electronic conﬁguration for this
state?
1. 1s2 2s2 2p6 3s2 3p2
2. 1s2 2s2 2p6 3s3 3p1 1
2
3
4. = 2, s =
2
3. = 1, s = Part 2 of 2
What are the possible values of the total angular momentum J ? Given the fact that there is
a spinorbit interaction, predict which of the
J values has a lower energy. (Hint: Use what
you learned about the spinorbit coupling in
hydrogen.)
3
3
5
1. , 2, , Jlowest =
2
2
2
5
3
5
2. , 2, , Jlowest =
2
2
2
5
3. 3, , 2, Jlowest = 2
2
31
4. 2, , , Jlowest = 24
22
Complex Atoms and Molecules 4
46:05, highSchool, multiple choice, < 1 min,
ﬁxed.
The last (most energetic) electron in
sodium is in a 3s state.
What do you expect the order of the energies to be for the last electrons in the three
possible states 3s, 3p, and 3d? 3. 1s2 2s2 2p6 3s1 3p3 1. 3d > 3p > 3s 4. 1s3 2s3 3p2 3s3 3p3 2. 3d > 3s > 3p Complex Atoms and Molecules 3
46:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
What are the orbital angular momentum
and spin of the ground state of scandium (Z =
21)?
1
2
3
2. = 1, s =
2 1. = 2, s = 341 3. 3p > 3s > 3d
4. 3s > 3p > 3d
5. 3s = 3p = 3d Chapter 46, section 10, Exchange Symmetry and the Exclusion Principle
Conceptual 24 Q14
46:10, highSchool, multiple choice, < 1 min,
ﬁxed.
The Pauli exclusion priciple says that no
two electrons can occupy the same energy
state unless their spin point in opposite directions.
In reference to this principle what happens
if the atoms have an even number of electrons.
1. have small Curie constants; magnetic ﬁeld
of the spins cancel out
2. have large Curie constants; magnetic ﬁeld
of spins add up with each other
3. None of these 342 Chapter 46, section 13, The Periodic Table
Conceptual 21 01
46:13, highSchool, multiple choice, < 1 min,
wordingvariable.
How many protons does hydrogen (H)
have?
1. 1 343 5. 36
Conceptual 21 04
46:13, highSchool, multiple choice, < 1 min,
wordingvariable.
How many protons does +1 of sodium (Na)
have? 2. 20 1. 11 3. 6 2. 35 4. 53 3. 82 5. 16 4. 26 Conceptual 21 02
46:13, highSchool, multiple choice, < 1 min,
wordingvariable.
How many electrons does hydrogen (H)
have?
1. 1
2. 6 5. 20
Conceptual 21 06
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
If you were told that ﬂuorine is an extremely reactive element (that is, it combines
readily with other elements), what other element(s) would be extremely reactive? 3. 53 1. All elements in the same column 4. 20 2. All elements on the same row 5. 16 3. All elements after ﬂuorine Conceptual 21 03
46:13, highSchool, multiple choice, < 1 min,
wordingvariable.
How many electrons does +1 of sodium
(Na) have? 4. All elements before ﬂuorine
5. None of these
Conceptual 21 07
46:13, highSchool, multiple choice, < 1 min,
ﬁxed. 1. 10
2. 18 If you were told that argon (Ar) is an exceptionally unreactive element, what other
elements would also be extremely unreactive? 3. 23
1. All elements in the same column
4. 78 Chapter 46, section 13, The Periodic Table
2. All elements on the same row 344 46:13, highSchool, multiple choice, < 1 min,
ﬁxed. 3. All elements after argon
4. All elements before argon Why do two hydrogen (H) atoms combine
with one oxygen (O) atom to form water
(H2 O)? 5. None of these
Conceptual 21 Q18
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
Silicon (Si) and nitrogen (N) are adjacent
to carbon (C) on the periodic table. Si and C
have many similar chemical properties but C
and N do not.
What does NOT account for the diﬀerence?
1. Carbon and silicon are in the same column
of the periodic table.
2. Carbon and silicon have same number of
electrons in their outer shells.
3. Carbon and Nitrogen are in the same
group
4. None of these 1. Two hydrogen donates its electron to oxygen.
2. Two hydrogen share its electrons with one
oxygen.
3. None of these
Conceptual 26 Q03
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
An atom has six neutrons, six protons, and
six electrons.
Which element or ion is it?
1. Ca2+
2. C
3. Li Conceptual 21 Q19
46:13, highSchool, multiple choice, < 1 min,
ﬁxed. 4. N Why is sodium chloride (NaCl) such a stable compound? 6. Mg2+ 5. Na+ 7. O2− 1. Sodium donates its electrons to chlorine.
8. None of these
2. Sodium donates the electron in it’s outer
most shell to chlorine.
3. Sodium and chlorine share the electrons. Conceptual 26 Q04
46:13, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Sodium and chlorine are volatile until
they form the compound. An atom has 143 neutrons, 92 protons, and
91 electrons. What element is it? 5. None of these
Conceptual 21 Q20 1. Pa
2. Th Chapter 46, section 13, The Periodic Table
3. Pu 345 Since most known isotopes are unstable,
how could this state of aﬀairs have arisen? 4. U 1. The unstable nuclei decayed long ago. 5. Cm 2. Very few atoms decay. 6. None of these
Conceptual 26 Q05
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
We know that the strong force acts very
short distances. Suppose the range of the
strong force were twice what it is now. (In
other words, it would attract the same particles with the same force as now, even though
they were twice as far away.)
What will happen to the halflife of
Uranium238?
1. decrease
2. increase 3. Unstable nuclei exist for only a small
period of time.
Hewitt CP9 32 E05
46:13, highSchool, multiple choice, > 1 min,
ﬁxed.
Uranium is 238 times more massive than
hydrogen.
Why, then, isn’t the diameter of the uranium atom 238 times that of the hydrogen
atom?
1. Uranium has 92 times as much positive
charge as hydrogen; this greater charge pulls
the surrounding electrons into tighter orbits.
2. There are very strong forces between nuclei in the uranium atom. 3. no change
Conceptual 26 Q06
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
Why does radioactivity seem to be more
common with heavier elements?
1. They have more number of electrons. 3. There are very few electrons in the uranium atom.
4. Most of the atom’s mass is localized in
the nucleus and most of the volume is deﬁned
by electrons’ orbits.
Hewitt CP9 32 E12
46:13, highSchool, multiple choice, < 1 min,
ﬁxed. 2. They have more number of protons.
3. They have less number of electrons. Why do atoms that have the same number
of electron shells decrease in size with increasing atomic number? 4. They have less number of protons.
Conceptual 26 Q07
46:13, highSchool, multiple choice, < 1 min,
ﬁxed.
Almost all of the atoms with which we come
into daily contact have stable nuclei. 1. The greater the atomic number, the fewer
electrons the atom can have.
2. The electron shells are pulled in more
tightly because of the larger number of protons in the nucleus. Chapter 46, section 13, The Periodic Table
3. Atoms decrease in size with increasing
atomic number in order to release energy.
4. Elements with great atomic numbers usually don’t react chemically with other elements. 346 Chapter 46, section 17, Lasers and Holography
Conceptual 21 Q07
46:17, highSchool, multiple choice, < 1 min,
ﬁxed.
Diﬀerent lasers have beams with diﬀerent
colors.
Which of these is NOT true?
1. Diﬀerent lasers use diﬀerent materials.
2. Diﬀerent materials have diﬀerent energy
levels for the electrons.
3. Diﬀerent energy photons emitted by electron transition between levels.
4. Diﬀernet lasers have diﬀerent electromagnetic radiation for diﬀerent materials.
5. None of these 347 Chapter 47, section 4, An Application of FermiDirac Statistics:
Many Particles 12
47:04, highSchool, numeric, < 1 min, ﬁxed.
Calculate the Fermi energy for potassium, for which the freeelectron density is
1.4 × 1028 electrons/m3 .
Many Particles 13
47:04, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Calculate the Fermi energy for Cu, for
which A = 63.5, ρ = 8950 kg/m3 and approximately one electron per atom is free.
Part 2 of 2
Repeat the calculation for lead, for which
A = 207.2, ρ = 11400 kg/m3 . Assume in the
case of lead that there are two free electrons
per atom. 348 Chapter 48, section 1, Bonding Mechanisms
Conceptual 09 Q4
48:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Consider techniques used to separate compounds and mixtures into components.
Which statement is false?
1. In a compound, molecules must be broken
apart to separate components.
2. In a mixture, components can be separated without destroying molecules.
3. Molecular structures are maintained
when separating compounds or mixtures into
components.
Conceptual 26 Q02
48:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Reacting hydrogen and oxygen atoms together produces water H2 O.
What would result from the fusion of two
hydrogen nuclei with an oxygen nucleus?
1. Oxygen
2. Hydrogen
3. Neon
4. Sodium
5. Magnesium
6. None of these 349 Chapter 48, section 99, Associated problems in Chapter 48 350 2. metallic bonds
Conceptual 23 01
48:99, highSchool, multiple choice, < 1 min,
wordingvariable. 3. covalent bonds
4. Either Part 1 of 2
Some elements readily form ionic or covalent bonds and some elements do not participate in chemical bonding at all.
Which element has an atomic number of 6? Conceptual 23 Q03
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What type of chemical bonds is the most
prevalent in biological molecules? 1. carbon
2. nitrogen 1. ionic bonds 3. hydrogen 2. metallic bonds Part 2 of 2
Is this element likely to participate in chemical bonding? Why?
1. Yes; it has an incomplete valance shell.
2. No; it has a full outer shell.
Conceptual 23 Q01
48:99, highSchool, multiple choice, < 1 min,
ﬁxed. 3. covalent bonds
4. Either
Conceptual 23 Q04
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following materials is your last
choice to build a house?
1. ionicbonded materials Which is a better choice to ﬁll a balloonlike
airship, hydrogen or helium?
1. Hydrogen; it is ligheter than helium. 2. metallicbonded materials
3. covalentbonded materials 2. Hydrogen; it is cheaper than helium. 4. materials held together by van der Waals
forces 3. Helium; hydrogen is very reactive.
Conceptual 23 Q05
48:99, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Helium; it smells good.
Conceptual 23 Q02
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What types
strongest? of chemical bonds the What is the relationship between the properties of a newly formed chemical compound
and the properties of the individual elements
that compose it?
1. Their properties can be very diﬀerent. 1. ionic bonds
2. Their properties are similar. Chapter 48, section 99, Associated problems in Chapter 48 351 1. MgCl
3. Their physical properties are similar.
2. MgCl2
4. Their chemical properties are similar.
3. Mg2 Cl
Conceptual 23 Q06
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
Diamonds and graphite are both made from
carbon atoms.
Why is graphite so much weaker?
1. Graphite is held together only by van der
Waals forces.
2. Graphite is held together only by ionic
bonds. 4. Mg2 Cl2
Conceptual 23 Q10
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the chemical formula for the covalent compound carbon chloride (carbon and
chlorine)?
1. CCl
2. CCl2 3. Graphite is only covalently bonded in
certain planes of atoms. Parallel planes are
bonded together with weak van der Waals
forces.
4. Diamonds are metallicbonded while
graphite is covalentbonded.
Conceptual 23 Q07
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What type of chemical bond does NaF
(sodium ﬂuoride) form? 3. CCl3
4. CCl4
Conceptual 23 Q11
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the chemical formula for the ionic
compound magnesium oxide (magnesium and
oxygen)?
1. MgO 1. ionic bond 2. MgO2 2. metallic bond 3. Mg2 O 3. covalent bond 4. MgO4 4. None of these
Conceptual 23 Q08
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
What is the chemical formula for the compound formed by magnesium and chlorine ? Conceptual 23 Q12
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
Potassium iodide can be used as a thyroidblocking agent in the event of a radiation
emergency.
What is the chemical formula for the ionic
compound potassium iodide (potassium and Chapter 48, section 99, Associated problems in Chapter 48 352 iodine)?
2. AlCl2
1. KI
3. AlCl3
2. KI2
4. Al2 Cl3
3. K2 I
5. Al2 Cl
4. KI4
Conceptual 23 Q13
48:99, highSchool, multiple choice, < 1 min,
ﬁxed. Part 2 of 2
Which element becomes the positive ion in
this compound?
1. Al Part 1 of 2
Magnesium (Mg) and bromine (Br) form
an ionic compound.
What is its chemical formula?
1. MgBr
2. BrMg
3. MgBr2 2. Cl
Conceptual 23 Q16
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
Chlorine and argon appear in adjacent
spots on the periodic table.
Which one is more reactive, chlorine or argon? Why? 4. Mg2 Br
5. Br2 Mg
6. BrMg2
Part 2 of 2
Which element becomes the positive ion in
this compound?
1. Mg
2. Br
Conceptual 23 Q15
48:99, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Aluminum (Al) and chlorine (Cl) combine
to form an ionic compound.
What is its chemical formula?
1. AlCl 1. Argon is more reactive; it has more electrons.
2. Chlorine is more reactive; argon has a full
outer shell.
3. Unable to determine Chapter 49, section 1, Bonding in Solids
Conceptual 26 Q01
49:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Mixing copper and zinc atoms forms the
alloy brass.
What would form if you fused the nucleus
of a copper atom with the nucleus of a zinc
atom?
1. Praseodymium
2. Zinc
3. Copper
4. Neodymium
5. Cerium
6. None of these
Hewitt CP9 12 E02
49:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What supports the claim that crystals are
composed of atoms that are arranged in speciﬁc patterns?
1. good conductivity
2. transparency
3. symmetric diﬀraction patterns
4. hardness 353 Chapter 49, section 9, Semiconductor Devices
Conceptual 25 01
49:09, highSchool, numeric, < 1 min, normal.
Part 1 of 2
There is an eﬀort in the world today to convert television into socalled high deﬁnition
TV(HDTV). In HDTV, the picture is split up
into many as 1100 by 1100 (as opposed to 550
by 550) pixels.
What is the information content of an
HDTV picture?
Give the answer in megabits.
Part 2 of 2
What is the information content that must be
transmitted each second in an HDTV broadcast?
Give the answer in gigabits per second.
Conceptual 25 04
49:09, highSchool, numeric, < 1 min, ﬁxed.
How many seconds do you have to listen
to a CD to receive as much information as
is contained in an average book? Assume an
average book contains about 4 × 106 bits of
information and a CD processes information
at a rate of 705000 bit/second.
Conceptual 25 05
49:09, highSchool, numeric, < 1 min, normal.
Part 1 of 3
The Encyclopedia Britannica contains
about 1800 words per page. There are 28 volumes and each volume has about 1000 pages.
What is the information content of the
words in a set of the encyclopedia in bits?
Give the answer in gigabits.
Part 2 of 3
What is the information content of the words
in a set of the encyclopedia in bytes?
Give the answer in megabytes.
Part 3 of 3
If a data storage capacity of 1 × 1012 bits per
square inch is reached, how many sets (not 354 volume) of the encyclopedia could ﬁt on an
ordinary CD?
Conceptual 25 07
49:09, highSchool, numeric, < 1 min, normal.
How much information is contained in a 300
page book? Assume 500 words on each page
and 36 bit of information in each word.
Conceptual 25 08
49:09, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Rosa writes a 20page paper for her extracredit history grade. Each page has an average of 26 lines, with 12 words words per
line.
How many bits of information has Rosa
generated in her paper?
Part 2 of 2
Can she store her paper on a normal mode
3.5inch ﬂoppy disk?
Conceptual 25 09
49:09, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
The Cyrillic alphabet (used to write Russian and some other Eastern European languages) was devised in the ninth century and
had 43 letters, whereas the alphabet used for
modern Russian has 30.
How many bits would it take to specify a
single letter in modern alphabets?
Part 2 of 2
How many bits would it take to specify a
single letter in Cyrillic alphabets?
Conceptual 25 10
49:09, highSchool, numeric, > 1 min, ﬁxed.
The version of modern written Japanese
called ”kanji” has 1945 diﬀerent characters.
How many bits would it take to specify
kanji character? Chapter 49, section 9, Semiconductor Devices
Conceptual 25 Q01
49:09, highSchool, multiple choice, < 1 min,
ﬁxed. 3. terahertz radiation If water in a pipe is analogous to electricity
in a wire, what is analogous to a diode and to
a transistor? 355 5. radiowaves 1. nothing; faucet
2. pipes; nothing 4. microwave Conceptual 25 Q09
49:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Which method most likely requires more
digital storage capacity? 3. faucet; pipes
4. Tconnection; elbow
5. elbow ; faucet 1. storing the words of a song using a wordprocessing program
2. storing an actual recording of the song on
a CD 6. Non of these.
3. storing using punch cards
Conceptual 25 Q06
49:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Would a diode result from taking two ntype semiconductor and placing them together?
1. No. An electrical ﬁeld will not be created
in an nn junction.
2. Yes. An electrical ﬁeld will be created in
an nn junction.
3. No. There will not be enough holes to create electric ﬁeld but some amount of electric
ﬁeld will be present.
Conceptual 25 Q08
49:09, highSchool, multiple choice, < 1 min,
ﬁxed.
Which would be more eﬀective at making a
photovoltaic cell work?
1. infrared light
2. ultraviolet light Conceptual 25 Q10
49:09, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
You have ﬁve pennies and ﬁve nickels in a
hat. You draw them out randomly and ﬂip
each coin.
How many bits of information are required
to record the sequence of coins drawn from
the hat (e.g., penny, nickel, penny, ....)?
Part 2 of 2
How many bits are required to record the
sequence of heads/tails? Chapter 49, section 10, Doped Semiconductors 356 ductor
Conceptual 25 Q02
49:10, highSchool, multiple choice, < 1 min,
wordingvariable.
What would a silicon semiconductor doped
with boron be?
1. ptype
2. itype
3. ntype
Conceptual 25 Q04
49:10, highSchool, multiple choice, < 1 min,
ﬁxed.
In order to make an ntype semiconductor,
silicon can be doped with a small amount of
phosphorus.
Why is arsenic also a good element to use
as a dopant?
1. Arsenic has many allotropic forms.
2. Arsenic has the same number of outer
shell electrons does of phosphorus.
3. Arsenic has similar atomic mass to phosphorus.
4. Arsenic has a similar atomic radius to
phosphorus.
Conceptual 25 Q05
49:10, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following has the highest electrical conductivity?
1. two phosphorus doped silicon semiconductor
2. three phosphorus doped silicon semiconductor
3. one phosphorus doped silicon semicon 4. silicon semiconductor without any doping Chapter 51, section 1, Discovering the Nucleus
Holt SF 25Rev 38
51:01, highSchool, numeric, > 1 min, ﬁxed.
Consider the hydrogen atom to be a sphere
with a radius equal to the Bohr radius,
0.53 × 10−10 m, and calculate the approximate value of the ratio of atomic density to
nuclear density.
Holt SF 25Rev 39
51:01, highSchool, numeric, > 1 min, ﬁxed.
Certain stars are thought to collapse at the
end of their lives, combining their protons and
electrons to form a neutron star. Such a star
could be thought of as a giant atomic nucleus.
If a star with a mass equal to that of the sun
(1.99 × 1030 kg) were to collapse into neutrons,
what would be the radius of the star? 357 Chapter 51, section 2, Some Nuclear Properties
Binding energy
51:02, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Calculate the total binding energy for 28 Si.
14
The mass of 28 Si is 27.9769 u, the mass of
14
the proton is 1.00782 u and the mass of the
neutron is 1.00866 u.
1. 236.539 MeV
2. 246.539 MeV 358 Calcuate the Qvalue for the He burning
reaction
4
2 He + 4 He → 8 Be + γ .
2
4 Take the mass of 4 He is 4.0026 u and of 8 Be is
8.0053 u, 1 uc2 = 931.5 MeV.
Express your ﬁnal answer in MeV.
Part 2 of 2
Calcuate the Qvalue for the He burning reaction
4
2 He + 8 Be → 12 C + γ .
4
6 Take the mass of 12 C is 12 u.
Express your ﬁnal answer in MeV. 3. 256.539 MeV
4. 266.539 MeV Holt SF 25A 01
51:02, highSchool, numeric, > 1 min, ﬁxed. 5. 226.539 MeV
6. 216.539 MeV
7. None of these
Part 2 of 2
What is the binding energy of the last protonelectron pair in 28 Si? The mass of 27 Al is
13
14
26.9815 u.
1. 11.5841 MeV Part 1 of 2
Calculate the total binding energy of 20 Ne.
10
Part 2 of 2
Calculate the total binding energy of 40 Ca.
20
Holt SF 25A 02
51:02, highSchool, numeric, > 1 min, ﬁxed.
Determine the diﬀerence in the binding energy of 3 H and 3 He.
2
1 2. 10 MeV
3. 0.115841 MeV
4. 21.5841 MeV Holt SF 25A 03
51:02, highSchool, numeric, > 1 min, ﬁxed.
Calculate the binding energy of the last
neutron in the 43 Ca nucleus. (Hint: Compare
20
the mass of 43 Ca with the mass of 42 Ca plus
20
20
the mass of a neutron.) 5. 31 MeV
6. 1.15841 MeV Holt SF 25A 04
51:02, highSchool, numeric, > 1 min, ﬁxed. 7. 115.841 MeV
8. None of these
He burning reaction
51:02, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2 Find the binding energy per nucleon of 238 U
92
in MeV.
Holt SF 25A 05
51:02, highSchool, numeric, > 1 min, ﬁxed. Chapter 51, section 2, Some Nuclear Properties
Two isotopes having the same mass number
are known as isobars.
Calculate the diﬀerence in binding energy
per nucleon for the isobars 23 Na and 23 Mg.
11
12
Holt SF 25Rev 07
51:02, highSchool, numeric, > 1 min, ﬁxed.
Calculate the total binding energy of 12 C.
6
Holt SF 25Rev 08
51:02, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Calculate the total binding energy of tritium (3 H).
1
Part 2 of 2
Calculate the total binding energy of helium3
(3 He).
2
Holt SF 25Rev 09
51:02, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Calculate the average binding energy per
nucleon of 24 Mg.
12
Part 2 of 2
Calculate the average binding energy per nucleon of 85 Rb.
37
Holt SF 25Rev 43
51:02, highSchool, numeric, > 1 min, ﬁxed.
A pair of nuclei for which Z1 = N2 and Z2 =
N1 are called mirror isobars (the atomic and
neutron numbers are interchangeable). Binding energy measurements on such pairs can
be used to obtain evidence of the charge independence of nuclear forces. Charge independence means that the protonproton, protonneutron, and neutronneutron forces are approximately equal.
Calculate the diﬀerence in binding energy
for the two mirror nuclei, 15 O (15.003065 u)
8
and 15 N (15.000108 u).
7
Holt SF 25Rev 44 359 51:02, highSchool, numeric, > 1 min, ﬁxed.
Find the threshold kinetic energy that the
incident neutron must have to produce the
following reaction:
1
4
0 n + 2 He → 2H + 3H
1
1 Chapter 51, section 3, Binding Energy and Nuclear Forces
Hewitt CP9 32 E31
51:03, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The higher the energy level occupied by an
electron in the hydrogen atom, the larger the
atom. The size of the atom is proportional to
n2 , where n = 1 labels the lowest, or ground
state, n = 2 is the second state, n = 3 is the
third state, and so on.
If the atom’s diameter is 1 × 10−10 m in its
lowest energy state, what is its diameter in
state number 25?
Part 2 of 2
How many unexcited atoms could ﬁt within
this one giant atom? 360 Chapter 51, section 4, Nuclear Models
Hewitt CP9 33 E01
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
X rays are most similar to which of the
following? 361 4. No; hydrogen cannot be broken apart.
Hewitt CP9 33 E042
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why are gamma rays not deﬂected? 1. Alpha rays
1. They have no electric charge.
2. Beta rays
2. They have a short lifetime.
3. Gamma rays
3. They have strong penetration ability.
Hewitt CP9 33 E02
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is a sample of radioactive material
always a little warmer than its surroundings?
1. The radioactive material has better heat
conduction than other materials.
2. The radiating alpha or beta particles impart internal energy to the atoms of the sample. 4. They don’t react chemically with other
materials.
5. They carry great energy.
Hewitt CP9 33 E04
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Why are alpha and beta rays deﬂected in
opposite directions in a magnetic ﬁeld?
1. They have diﬀerent masses. 3. The radioactive material always has a
rapid chemical reaction inside.
4. Heat is easier to get into radioactive materials than other materials.
Hewitt CP9 33 E03
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Some people say that all things are possible.
Is it possible for a hydrogen nucleus to emit
an alpha particle? 2. They have diﬀerent lifetimes.
3. They have diﬀerent penetration abilities.
4. They are oppositely charged.
5. They have diﬀerent chemical characteristics.
Hewitt CP9 33 E06
51:04, highSchool, multiple choice, < 1 min,
ﬁxed. 1. Yes
2. No; hydrogen cannot participate in nuclear reactions.
3. No; an alpha particle has four nucleons –
two protons and two neutrons. How do the paths of alpha, beta, or gamma
rays compare in an electric ﬁeld?
1. Alpha and beta particles are pushed in
the same direction by an electric ﬁeld; gamma
rays are unaﬀected. Chapter 51, section 4, Nuclear Models
a uranium mine?
2. Gamma and beta rays are pushed oppositely by an electric ﬁeld; alpha rays are
unaﬀected. 1. alpha
2. beta 3. Alpha and gamma rays are pushed oppositely by an electric ﬁeld; beta rays are
unaﬀected.
4. Alpha and beta particles are pushed oppositely by an electric ﬁeld; gamma rays are
unaﬀected.
5. Alpha, beta and gamma rays are pushed
in the same direction.
Hewitt CP9 33 E07
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which type of radiation produces the greatest change in mass number when emitted by
an atomic nucleus?
1. alpha
2. beta
3. gamma
Hewitt CP9 33 E08
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which type of radiation produces the least
change in mass number?
1. alpha
2. beta
3. gamma
Hewitt CP9 33 E09
51:04, highSchool, multiple choice, < 1 min,
ﬁxed.
Which type of radiation predominates
within an enclosed elevator descending into 3. gamma 362 Chapter 51, section 5, Radioactivity 363 Conceptual 26 Q10
51:05, highSchool, multiple choice, < 1 min,
ﬁxed. A radioactive isotope is found to decay to
onesixteenth its original amount in 12 years.
What is the halflife of this isotope? Suppose you are a scientist from the future
who has discovered the ruins of the Empire
State Building.
How would you go about estimating the
date when it was built? Conceptual 26 Q13
51:05, highSchool, numeric, < 1 min, ﬁxed. 1. Try to ﬁnd artifacts made of organic material.
2. Try to ﬁnd old belongings to consult with
a historian.
Conceptual 26 Q11
51:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Carbon14 decays by beta decay with a half
life of 5700 years.
What does a carbon14 nucleus become
when it undergoes beta decay?
1. Nitrogen14 A radioactive isotope is found to decay to
oneeighth its original amount in 30 years.
What is the halflife of this isotope?
Conceptual 26 Q14
51:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Part 1 of 2
Is it possible for a radioactive nucleus to decay two times and end up as the same element
that it started as?
1. Yes; if it were two gamma decays.
2. Yes; if it were alpha and gamma decays.
3. Yes; if it were beta and gamma decays.
4. No; its impossible to end up as the same
element. 2. Uranium234
3. Radium226 Part 2 of 2
What if the nucleus were restricted to alpha
and beta decays only? 4. Lead206
5. Polonium218 1. Yes; if it were two alpha decays.
2. Yes; if it were two beta decays. 6. Bismuth214
3. Yes; if it were beta and alpha decays.
Part 2 of 2
If an ancient campﬁre were analyzed, and
it was found to have only about oneeighth
the carbon14 that is normally found in living things, how long ago was that campﬁre
extinguished?
Conceptual 26 Q12
51:05, highSchool, multiple choice, < 1 min,
ﬁxed. 4. No; its impossible.
Holt SF 25B 01
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Complete this radioactivedecay formula:
→? +−0e + ν
1 12
5B Chapter 51, section 5, Radioactivity
1. 12 C
6
2. 12 Be
4
3. 11 O
8 364 Holt SF 25B 04
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Complete this radioactivedecay formula:
→221 Fr +?
87 4. 10 F
9 225
89 Ac 5. 10 B
5 1. 4 He
2 6. None of these 2. 2 2 H
1 Holt SF 25B 02
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Complete this radioactivedecay formula:
→?+4 He
2 212
83 Bi 1. 208 Tl
81
2. 208
81 Hg 3. 216
85 At 4. 216 Po
85
5. 208 At
85
6. 216
81 Tl 3. The reaction is impossible.
4. None of these
Holt SF 25B 06
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
The isotope 56
27 Co. 56
26 Fe decays into the isotope By what process will this decay occur? 1. β −
2. β +
3. α
4. γ 7. None of these
5. None of these
Holt SF 25B 03
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Complete this radioactivedecay formula:
? →14 N +−0 e + ν
7
1
1. 14 C
6
2. 12 C
6
3. 14 O
8
4. 15 B
6
5. None of these Holt SF 25C 01
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2 The halflife of 214 Po is 164
84 µs. A polonium214 sample contains 2.0 × 106 nuclei.
a) What is the decay constant for the decay?
Part 2 of 2
b) How many polonium nuclei, in curies, will
decay per second?
Holt SF 25C 02 Chapter 51, section 5, Radioactivity
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The halflife of 214 Bi is 19.7 min.
A
83
9
bismuth214 sample contains 2.0 × 10 nuclei.
a) What is the decay constant for the decay?
Part 2 of 2
b) How many bismuth nuclei, in curies, will
decay per second?
Holt SF 25C 03
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The halflife of 131 I is 8.07 days.
53
a) Calculate the decay constant for this
isotope.
Part 2 of 2
b) What is the activity in Ci for a sample that
contains 2.5 × 1010 iodine131 nuclei?
Holt SF 25C 04
51:05, highSchool, numeric, > 1 min, normal.
Suppose that you start with 1.23 g of a pure
radioactive substance and determine 4 h later
that only 0.076875 g of the substance is left
undecayed.
What is the halflife of this substance?
Holt SF 25C 05
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
222
Radon222 ( 86 Rn) is a radioactive gas with
a halflife of 3.82 days. A gas sample contains
4.0 × 108 radon atoms initially.
a) Determine how many radon atoms will
remain after 12 days.
Part 2 of 2
b) Determine how many radon nuclei will have
decayed by this time. 365 Holt SF 25Rev 23
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Determine the missing product of the following reaction:
7
4
1
3 Li+2 He →? +0 n
1. 10 B
5
2. 11 B
5
3. 10 Be
5
4. 11 C
5
5. 3 H
1
Holt SF 25Rev 24
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
A nuclear reaction of signiﬁcant historical note occurred in 1932, when a beryllium
target was bombarded with alpha particles.
Analysis of the experiment indicated that the
following reaction occurred:
4
9
12
2 He+4 Be → 6 C+X
What is X in this reaction?
1. 1 n
0
2. 0 n
1
3. 0 e
1
4. 1 e
0
5. γ
6. None of these
Holt SF 25Rev 25
51:05, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Complete the following nuclear reaction: Chapter 51, section 5, Radioactivity
?+14 N →1 H+17 O
7
1
8
1. 4 He
2
2. 2 H
1
3. 2 He
2
4. 22 H
1 366 variable.
The amount of carbon14 (14 C) in a wooden
6
artifact is measured to be 6.25 percent the
amount in a fresh sample of wood from the
same region. The halflife of carbon14 is 5730
years.
Assuming the same amount of carbon14
was initially present in the artifact, determine
the age of the artifact. 5. None of these
Part 2 of 2
Complete the following nuclear reaction:
7
1
4
3 Li+1 H →2 He+?
1. 4 He
2
2. 8 Be
4
3. 3 He
2
4. 22 H
1
5. None of these
Holt SF 25Rev 26
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
A radioactive sample contains 1.67 × 1011
atoms of 108 Ag ( halflife= 2.42 min) at some
47
instant.
Calculate the decay constant.
Part 2 of 2
b) Calculate the activity of the sample in
mCi.
Holt SF 25Rev 27
51:05, highSchool, numeric, > 1 min, ﬁxed.
How long will it take a sample of polonium210 with a halflife of 140 days to decay to
onesixteenth its original strength?
Holt SF 25Rev 28
51:05, highSchool, numeric, > 1 min, wording Holt SF 25Rev 29
51:05, highSchool, numeric, > 1 min, wordingvariable.
A sample of organic material is found to
contain 18 g of carbon. Based on samples of
pottery found at the site, investigators believe
the material is about 23000 years old.
Estimate what percentage of the material’s
carbon14 has decayed.
Holt SF 25Rev 54
51:05, highSchool, numeric, > 1 min, wordingvariable.
A piece of charcoal known to be approximately 25000 years old contains 7.96 × 1010
C14 atoms.
Determine the number of decays per minute
expected from this sample.
Holt SF 25Rev 55
51:05, highSchool, numeric, > 1 min, wordingvariable.
Part 1 of 2
The halflife of radium228 is 5.76 years.
At some instant a sample contains 2.0 × 109
nuclei.
a) Calculate the decay constant.
Part 2 of 2
b) Calculate the activity of the sample in Ci.
Holt SF 25Rev 56
51:05, highSchool, numeric, > 1 min, wordingvariable. Chapter 51, section 5, Radioactivity
A sample of a radioactive isotope is measured to have an activity of 240.0 mCi.
If the sample has a halflife of 14 days, how
many nuclei of the isotope are there at this
time?
Holt SF 25Rev 57
51:05, highSchool, numeric, > 1 min, wordingvariable.
At some instant of time the activity of a
sample of radioactive material is 5.0 µCi.
If the sample contains 1.0 × 109 radioactive
nuclei, what is the halflife of the material?
Holt SF 25Rev 58
51:05, highSchool, numeric, > 1 min, ﬁxed.
Smoke detectors use the isotope 241 Am in
their operation. The halflife of Am is 432
years.
If the smoke detector is improperly discarded in a landﬁll, estimate how long it will
take for its activity to reduce to a relatively
safe level of 0.1 percent of its original activity?
(Hint: The estimation process you should use
notes that the activity reduces to 50% in one
halflife, to 25% in two halflives, and so on.) 367 Chapter 51, section 6, Decay Processes
Holt SF 25Rev 41
51:06, highSchool, numeric, > 1 min, ﬁxed.
Find the energy released in the alpha decay
of 238 U. Use the masses in the following table:
92
Nucleus Mass 238
92 U 238.050 784 u 234
90 Th 234.043 593 u 4
2 He 4.002 602 u 368 Chapter 51, section 8, Beta Decay
Holt SF 25B 05
51:08, highSchool, multiple choice, > 1 min,
ﬁxed.
Nickel63 decays by β − emission to copper63.
Write the complete decay formula for this
process.
1. 63 Ni →63 Cu +−0e + ν
28
29
1
2. 63 Ni →63 Cu +0e + ν
28
29
1
3. 63 Ni →63 Cu + γ
28
28
0
4. 63 Ni →63 Cu +4 He +−1e
28
29
2 5. None of these
Holt SF 25Rev 40
51:08, highSchool, numeric, > 1 min, ﬁxed.
Tritium, 3 H, decays to 3 He by beta emis2
1
sion.
Determine the energy released in the process. 369 Chapter 51, section 12, Radioactive Dating
Hewitt CP9 33 q07
51:12, highSchool, multiple choice, < 1 min,
ﬁxed.
Carbon dating allows us to
1. understand the motion of the Moon
around the Earth.
2. explain global warming.
3. discover the age of dead bodies.
4. keep an accurate daily calendar. 370 Chapter 52, section 1, Nuclear Reactions 371 obtained?
Atomic Nucleus 25
52:01, highSchool, numeric, > 1 min, ﬁxed.
Mirror nuclei are pairs of nuclei in which
the numbers of protons and neutrons are exchanged. 11 B(boron; Z = 5) and 11 C(carbon;
Z = 6) are examples.
Show that if the nn nuclear force diﬀered
from the pp nuclear force, the masses of the
mirror nuclei would have a nonzero contribution from this eﬀect. Such a term is explicitly
ruled out in the semiempirical mass formula.
Compare a calculation of the mass diﬀerence
from the semiempirical mass formula with the
measured mass diﬀerence of 1.98 MeV/c2 .
Atomic Nucleus 29
52:01, highSchool, numeric, < 1 min, ﬁxed. 1. nuclear reactor
2. gaseous diﬀusion
3. ultra centrifuge
4. mines
Hewitt CP9 33 q02
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
How is Pu239 for atomic weapons currently
obtained?
1. nuclear reactor
2. gaseous diﬀusion What is the minimum energy that can be
released in the reaction n +235 U →93 Rb +141
Cs + 2 n?
(The mass of 93 Rb is 92.9217 u, the mass
of 141 Cs is 140.919 u, the mass of 235 U is
235.044 u and the mass of n is 1.00866 u.)
Atomic Nucleus 31
52:01, highSchool, numeric, > 1 min, ﬁxed.
In his experiment to identify the neutron,
Chadwick used the reaction
α +11 B → n +14 N.
He measured the kinetic energies of the particles involved, which were 5.26 MeV for the
αparticle, 3.26 MeV for the neutron, and
0.57 MeV for the nitrogen nucleus; the boron
nucleus was at rest. The mass of 11 B is
11.0093 u, the mass of 14 N is 14.0031 u and
the mass of αparticle is 4.0026 u.
Using these data, ﬁnd the mass of the neutron.
Hewitt CP9 33 q01
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
How is U235 for atomic weapons currently 3. ultra centrifuge
4. mines
Hewitt CP9 33 q03
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What explains why chain reactions do not
take place in pure natural uranium?
1. The main component of natural uranium
U235 does not lead to chain reactions.
2. The main component of natural uranium
U238 doesn’t ﬁssion.
3. There is usually not enough uranium
localized in one place to overcome critical
mass.
4. Natural uranium is not pure.
Hewitt CP9 33 q04
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
What did Rutherford discover? Chapter 52, section 1, Nuclear Reactions 372 of U238 in uranium ore.
1. radioactive decay
2. Gold is heavier than lead.
3. Electrons do not scatter alpha particles.
4. The nucleus is much smaller than the
atom.
Hewitt CP9 33 q05
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Which of the following was explained by
the Bohr atom?
1. the fact that most of the mass of an atom
is in the nucleus
2. the photoelectric eﬀect 2. Uranium ore doesn’t contain particles active enough to induce a chain reaction.
3. Uranium in ore is mixed with other substances that impede the reaction and has no
moderator to slow down the neutrons.
4. There is no uranium deposit in the world
large enough for a chain reaction.
Hewitt CP9 34 E02
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Some heavy nuclei, containing even more
protons than the uranium nucleus, undergo
“spontaneous ﬁssion”, splitting apart without
absorbing a neutron.
Why is spontaneous ﬁssion observed only
in the heaviest nuclei? 3. atomic spectra
4. nuclear ﬁssion
Hewitt CP9 33 q06
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
To achieve a chain reaction, what is most
important?
1. high density 1. Gravitational forces are small for light
nuclei.
2. In a heavy atom, the outmost electrons
are very far from the center of the atom.
3. A light nucleus does not have enough
energy for ﬁssion.
4. The electric attraction between protons is
weaker than the repulsive nuclear force in the
heaviest nuclei. 2. high temperature
3. neutron multiplication less than 1 Hewitt CP9 34 E03
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. 4. neutron multiplication greater than 1
Hewitt CP9 34 E01
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why doesn’t uranium ore spontaneously
undergo a chain reaction?
1. There is not a high enough concentration Why is nuclear ﬁssion not likely to be used
directly for powering automobiles?
1. A ﬁssion reactor has a critical mass. Its
minimum size is too large to power a small
vehicle.
2. The power generated by nuclear ﬁssion is
enormous and cannot be reduced to meet the Chapter 52, section 1, Nuclear Reactions 373 needs of one automobile. tional force. 3. External nuclear radioactivity can harm
the driver. 4. Larger materials have a greater electric
force. 4. We haven’t found a good way to control
nuclear ﬁssion. Hewitt CP9 34 E06
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. 5. Nuclear reactions are harmful for the environment.
Hewitt CP9 34 E04
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. Which shape is likely to need less material
for a critical mass?
1. a cube
2. a cone Why does a neutron make a better nuclear
probe than a proton or an electron?
1. A neutron is more stable than a proton or
an electron. 3. a sphere
4. a hexahedron
5. a cylinder 2. A neutron takes more power when it
moves.
3. A neutron has greater mass than both a
proton and an electron.
4. A neutron does not react chemically with
other neuclei.
5. A neutron has no electric charge and
is therefore not repelled by an atomic nucleus. Hewitt CP9 34 E07
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Does the average distance that a neutron
travels through ﬁssionable material before escaping increase or decrease when two pieces
of ﬁssionable material are assembled into one
piece? Does this assembly increase or decrease the probability of an explosion?
1. Both decrease. Hewitt CP9 34 E05
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. 2. increases; decreases
3. decreases; increases Why will the escape of neutrons be proportionally less in a large piece of ﬁssionable
material than in a smaller piece? 4. Both increase. 1. Larger materials have a greater nuclear
force. Hewitt CP9 34 E09
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. 2. Larger materials have proportionally less
surface area per volume. Why does plutonium not occur in appreciable amounts in natural ore deposits? 3. Larger materials have a greater gravita 1. Plutonium has a relatively short half Chapter 52, section 1, Nuclear Reactions
life.
2. Plutonium has a relatively long half life. 374 4. to restrict radioactive contamination to
the reactor itself and to prevent interaction
of the contaminants with the outside environment 3. Plutonium has a relatively heavy mass.
4. Plutonium easily reacts chemically with
other materials.
5. Plutonium is a gas.
Hewitt CP9 34 E10
52:01, highSchool, multiple choice, < 1 min,
ﬁxed. Hewitt CP9 34 E13
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Why is carbon better than lead as a moderator in nuclear reactors?
1. Carbon can be manipulated easier than
lead. Why, after a uranium fuel rod reaches the
end of its fuel cycle (typically 3 years) does
most of its energy come from the ﬁssioning of
plutonium? 2. A lead nucleus is more massive than a
carbon nucleus. 1. Plutonium builds up over time because it
is produced by proton absorption in U238 . 4. Lead is too dangerous for human health. 2. Plutonium builds up over time because it
is produced by electron absorption in U238 .
3. Plutonium builds up over time because
it is produced by alpha particle absorption in
U238 .
4. Plutonium builds up over time because it
is produced by neutron absorption in U238 .
Hewitt CP9 34 E12
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
The water that passes through a reactor
core does not pass into the turbine; instead,
heat is transferred to a separate water cycle
that is entirely outside the reactor.
Why is this done? 3. Carbon has more isotopes than lead. Hewitt CP9 34 E14
52:01, highSchool, multiple choice, < 1 min,
ﬁxed.
Is the mass of an atomic nucleus greater or
less than the sum of the masses of the nucleons
composing it? Why don’t the nucleon masses
add up to the total nuclear mass?
1. Less; work must be done to separate a
nucleus into its component nucleons.
2. More; other energies are contained in a
nucleus that the nucleon components don’t
have.
3. Less; some electrons disappear when the
nucleon components form a nucleus.
4. More; a nucleus is larger than the sum of
the nucleon components. 1. to create more power
2. to avoid accidental explosions Holt SF 25Rev 50
52:01, highSchool, multiple choice, > 1 min,
ﬁxed. 3. to obtain more coolant
When 18 O is struck by a proton, 18 F and Chapter 52, section 1, Nuclear Reactions
another particle are produced.
What is the other particle?
1. 1 n
0
2. 21 n
0
3. 0 e−
1
4. 4 He
2
5. 1 H
1
6. 2 H
1
7. None of these
Holt SF 25Rev 51
52:01, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Complete the following nuclear reactions:
a) 27 Al+4 He →?+30 P
15
2
13
1. 1 n
0
2. 1 H
1
3. 4 He
2
4. 2 Be
4
5. 10 Be
4
Part 2 of 2
b) 1 n+? → 4 He+7 Li
0
2
3
1. 10 B
5
2. 10 Be
4
3. 2 H
1
4. 12 C
6
5. 11 B
5 375 Chapter 52, section 3, Interactions Involving Neutrons
Atomic Nucleus 05
52:03, highSchool, numeric, > 1 min, ﬁxed.
In this problem you will use the semiempirical mass formula to conclude that the nucleus is, to a good approximation, incompressible. Start by noting that the volume term
in the formula dominates for, say, A greater
than 100. We can call the resulting energy
Evol = −bvol A.
Express Evol as a function of radius. By
how much is the energy altered for a change
in volume that results from an overall change
in the radius ∆R? In addition to providing an
analytic answer, evaluate your result numerically by ﬁnding the energy change for a 0.01
change in the radius. Your numbers should be
on the order of 50 MeV per nucleon– such a
large number that you can conclude that the
nucleus is incompressible.
Holt SF 25Rev 46
52:03, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Natural gold has only one stable isotope,
197
79 Au. If gold is bombarded with slow neutrons, β − particles are emitted.
a) Which of the following is the correct
reaction equation?
0
1. 1 n +197Au →198 Pt ++1e + ν
0
79
78 2. 197 +−0e + ν →196 Pt + 1 n
Au
79
1
78
0
3. 1 n +197Au →197 Au +−0e + ν
0
79
79
1
4. 1 n +197Au →198 Hg +−0e + ν
1
80
79
0
5. 1 n +198Hg →197 Au +−0e + ν
0
80
79
1
6. 4 He +197Au →201 Pb +−0e + ν
1
82
79
2
7. None of these
Part 2 of 2
b) Calculate the maximum energy of the emitted beta particles. 376 Chapter 52, section 4, Nuclear Fission
Atomic Nucleus 02
52:04, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Given that it may take as much as 10 MeV
to remove a nucleon from a nucleus, estimate
the diﬀerence between the mass of a nucleus
and the sum of the masses of the nucleons
that compose it.
Part 2 of 2
How big is the corresponding eﬀect in atoms
if we regard the atomic constituents as the
nucleus as a whole plus the electrons?
Atomic Nucleus 04
52:04, highSchool, numeric, > 1 min, ﬁxed.
13 377 Holt SF 25Rev 47
52:04, highSchool, multiple choice, > 1 min,
ﬁxed.
Part 1 of 2
Consider the two ways 235 U can undergo
ﬁssion when bombarded with a neutron. In
each case, neutrons are also released.
Find the number of neutrons released when
140
Xe and 94 Sr are released as ﬁssion fragments.
1. 2
2. 1
3. 3
4. 4 13 Consider the nuclei N(Z = 7) and C
(Z = 6). The diﬀerence in mass between
them is measured to be 1.19 MeV/c2 .
Which terms in the semiempirical mass formula contribute to that diﬀerence? Use your
answer in conjunction with the expression for
the coulomb energy in the semiempirical mass
formula, (3/5) Z 2 e2 /(4 π 0 R0 A1/3 ), to calculate R0 . 5. None of these
Part 2 of 2
Find the number of neutrons released when
132
Sn and 101 Mo are released as ﬁssion fragments.
1. 3 Concept 34 E15
52:04, highSchool, multiple choice, < 1 min,
ﬁxed. 2. 1 The energy release of nuclear ﬁssion is tied
to the fact that the heaviest nuclei have about
0.1% more mass per nucleon than nuclei near
the middle of the periodic table of elements.
What would be the eﬀect on energy release
if the 0.1% ﬁgure were 1.0% instead? 4. 4 1. the same as before
2. one tenth of the original energy release
3. ten times the original energy release
4. a hundred times the original energy release 3. 2 5. None of these
Holt SF 25Rev 48
52:04, highSchool, multiple choice, > 1 min,
ﬁxed.
When a 6 Li nucleus is struck by a proton,
3
an alpha particle and a product nucleus are
released.
What is the product nucleus?
1. 3 He
2
2. 4 He
2 Chapter 52, section 4, Nuclear Fission
3. 3
2 Li 4. 1 H
1
5. 3 H
1
6. None of these
Holt SF 25Rev 52
52:04, highSchool, multiple choice, > 1 min,
ﬁxed.
A ﬁssion reaction that occurs when
uranium235 absorbs a neutron leads to the
formation of barium141 and krypton92.
a) What is the missing product in this reaction? ergy to keep a 100.0 W light bulb burning for
1.0 h.
Holt SF 25Rev 61
52:04, highSchool, numeric, > 1 min, wordingvariable.
How many atoms of 235 U must undergo
ﬁssion to operate a 1.0 × 103 MW power plant
for one day if the conversion eﬃciency is 30.0
percent? Assume 208 MeV released per ﬁssion
event.
Holt SF 25Rev 62
52:04, highSchool, numeric, > 1 min, wordingvariable.
An allelectric home uses about 2.0 ×
10 kW · h of electrical energy per month.
How many 235 U atoms would be required
to provide this house with its energy needs for
one year? Assume 100.0 percent conversion
eﬃciency and 208 MeV released per ﬁssion.
3 1. 31 n
0
2. 21 n
0
3. 4 He
2
4. 3 He
2
5. 3 H
1
Holt SF 25Rev 59
52:04, highSchool, numeric, > 1 min, ﬁxed.
It has been estimated that Earth has
9.1 × 1011 kg of natural uranium that can
be economically mined. Of this total, 0.70
percent is 235 U.
If all the world’s energy needs (7.0 ×
12
10 J/s) were supplied by 235 U ﬁssion, how
long would this supply last? Assume that 208
MeV of energy is released per ﬁssion event and
the mass of 235 U is about 3.9 × 10−25 kg.
Holt SF 25Rev 60
52:04, highSchool, numeric, > 1 min, wordingvariable.
If the average energy released in a ﬁssion
event is 208 MeV, ﬁnd the total number of
ﬁssion events required to provide enough en 378 Chapter 52, section 6, Nuclear Reactors 379 Concept 34 E21
52:06, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Splitting light nuclei yields energy; the
total mass of the products is less than the
total mass of the fusing nuclei. Heavy nuclei can be made to fuse; for instance, by ﬁring one gold nucleus at another
one.
Does such a process yield energy or cost
energy? Why? Conceptual 26 Q08
52:06, highSchool, multiple choice, > 1 min,
wordingvariable. 1. Fusing heavy nuclei yields energy; the
total mass of the products is greater than the
total mass of the fusing nuclei.
2. Fusing heavy nuclei costs energy; the total
mass of the products is greater than the total
mass of the fusing nuclei. Which of the following is the disadvantage
of nuclear power?
1. high expense of nuclear generating plant
2. can generate enormous amount of energy
from a very small amount of material
3. cannot generate enough energy 3. Fusing heavy nuclei costs energy; the total
mass of the products is less than the total
mass of the fusing nuclei. Conceptual 26 Q09
52:06, highSchool, multiple choice, < 1 min,
ﬁxed. 4. Fusing heavy nuclei yields energy; the
total mass of the products is less than the
total mass of the fusing nuclei. Can nuclear radiation escape from nuclear
plants? Concept 34 E22
52:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Light nuclei can be split. For instance a
deuteron (protonneutron combination) can
be caused to split into a single proton and
single neutron.
Does such a process yield energy or cost
energy? Why?
1. Splitting light nuclei costs energy; the
total mass of the products is greater than the
total mass of the fusing nuclei.
2. Splitting light nuclei costs energy; the
total mass of the products is less than the
total mass of the fusing nuclei.
3. Splitting light nuclei yields energy; the
total mass of the products is greater than the
total mass of the fusing nuclei. 1. Yes; the surrounding of the plant is hazardous.
2. Yes; nothing as such can block it completely.
3. No; but small amounts of gamma radiation will escape.
4. No; no radiation will escape.
Hewitt CP9 33 q10
52:06, highSchool, multiple choice, < 1 min,
ﬁxed.
What is needed for controlled thermonuclear reactions to work?
1. high temperature
2. long time
3. high density Chapter 52, section 6, Nuclear Reactors
4. All of these
5. None of these 380 Chapter 52, section 8, Nuclear Fusion
Concept 34 E16
52:08, highSchool, multiple choice, < 1 min,
ﬁxed.
In what ways are ﬁssion and fusion reactions similar?
1. Both involve the transformation of one or
more elements into other elements.
2. Both have critical masses.
3. Both require high temperatures. 381 4. fusion; fusion; neither
Concept 34 E27
52:08, highSchool, multiple choice, > 1 min,
ﬁxed.
Which produces more energy:
ﬁssioning a single uranium nucleus or fusing
a pair of deuterium nuclei?
ﬁssioning a gram of uranium or fusing a
gram of deuterium?
1. ﬁssioning a single uranium nucleus; fusing
deuterium 4. Both need both heavy and light nuclei.
Concept 34 E17
52:08, highSchool, multiple choice, < 1 min,
xed.
Chemical burning is similar to nuclear fusion in many aspects.
Which statement is not correct?
1. Both require minimum ignition temperature to start. 2. fusing a pair of duterium nuclei; fusing
deuterium
3. ﬁssioning a single uranium nucleus; ﬁssioning uranium
4. fusing a pair of duterium nuclei; ﬁssioning
uranium
Holt SF 25Rev 49
52:08, highSchool, multiple choice, > 1 min,
ﬁxed. 2. Both have critical masses.
3. Any amount of thermonuclear fuel or of
combustible fuel can be stored.
4. In both the reaction is spread by heat
from one region to neighboring regions. Suppose 10 B is struck by an alpha particle,
5
releasing a proton and a product nucleus in
the reaction.
What is the product nucleus?
1. 13 C
6 Concept 34 E23
52:08, highSchool, multiple choice, < 1 min,
ﬁxed. 2. 5 He
2 Which process (ﬁssion or fusion) would release energy from gold, from carbon, and from
iron? 4. 15 O
8 1. ﬁssion; fusion; neither
2. ﬁssion; ﬁssion; fusion
3. fusion; ﬁssion; neither 3. 12 C
6 5. 13 B
5
6. None of these
Holt SF 25Rev 53
52:08, highSchool, multiple choice, > 1 min,
ﬁxed. Chapter 52, section 8, Nuclear Fusion
Part 1 of 2
When a star has exhausted its hydrogen
fuel, it may fuse other nuclear fuels, such as
helium. At temperatures above 1.0 × 108 K,
helium fusion can occur.
a) Two alpha particles fuse to produce a
nucleus A and a gamma ray.
What is nucleus A?
1. 8 Be
4
2. 42 H
1
3. 6 Be
4
4. 8 B
5
5. None of these
Part 2 of 2
b) Nucleus A absorbs an alpha particle to
produce a nucleus, B, and a gamma ray.
What is nucleus B?
1. 12 C
6
2. 4 He
2
3. 12 B
6
4. 62 H
1
5. None of these 382 Chapter 52, section 14, Radiation Detectors
Atomic Nucleus 16
52:14, highSchool, numeric, < 1 min, normal.
14 C decays with a lifetime of 8270 yr.
What is the 14 C activity, deﬁned to be the
number of decays per unit time in a sample of
the material, expected in a timber structure
that is 1200 yr years old? Give your results
as a ratio of the activity of a sample of the
timber to that of the samesized sample of
modern wood. 383 Chapter 53, section 1, Elementary Particles
Conceptual 27 07
53:01, highSchool, numeric, > 1 min, wordingvariable.
One naturally occuring reaction in a radioactive decay process is nitrogen12 (atomic
number 7) decaying into carbon12 (atomic
number 6) plus an unknown particle.
What is the charge of this unknown particle?
Conceptual 27 08
53:01, highSchool, numeric, > 1 min, ﬁxed.
Some astronomers have theorized that
galaxies (matter) and antigalaxies (antimatter) have existed. Each galaxy contains about
1011 masses of the Sun (the mass of the Sun
is 1.9 × 1030 kg).
Calculate the total energy released if a
matterantimatter galaxy pair annihilated.
Conceptual 27 09
53:01, highSchool, numeric, > 1 min, ﬁxed.
Temperature can be related to energy by
1
the equation E = k T, where the tempera2
ture T is in Kelvin and k = 1.38 × 10−23 J/K.
What is the diﬀerence in the temperatures
generated between an electronpositron annihilation and a protonneutron annihilation? 384 Chapter 53, section 2, The Fundamental Forces in Nature
Conceptual 27 01
53:02, highSchool, multiple choice, > 1 min,
wordingvariable.
Part 1 of 2
Arrange the four fundamental forces according to strength from strongest to weakest.
1. gravity; strong nuclear force; weak nuclear force; electromagnetic force
2. strong nuclear force; weak nuclear force;
electromagnetic force; gravity
3. electromagnetic force; strong nuclear
force; weak nuclear force; gravity
4. strong nuclear force; weak nuclear force;
gravity; electromagnetic force
Part 2 of 2
What is the range of gravity?
1. long range
2. very short range
3. short range
4. None of these
Steady state model
53:02, highSchool, numeric, > 1 min, normal.
Estimate the rate at which hydrogen
atoms would have to be created, according to the steadystate model, to maintain
the present density of the unverse of about
5 × 10−27 kg/m3 ,
Assume the radius of the universe is 1 ×
1011 ly, mass of the hydrozen atom is 1.67 ×
10−27 kg and the universe is expanding with
Hubble constant 80 km/s/Mpc.
Express the answer in atoms/km3 /yr.
Threshold temp for particle prod
53:02, highSchool, numeric, > 1 min, ﬁxed. 385 Part 1 of 3
Determine the thereshold temperature for
producing various particles below.
Additional exercises: (NOT to be submitted to homework service.)
Based on the “temperature/time” plot for the
history of the universe after the big bang,
estimate the time when each of the threshold
productions occurs. See if your answer agrees
with the explanation to within a factor of 10,
after the homework is due.
a) kaons (M ≈ 500 MeV/c 2 ).
Part 2 of 3
b) Υ (M ≈ 9500 MeV/c 2 ).
Part 3 of 3
c) muons (M ≈ 100 MeV/c 2 ). Chapter 53, section 5, Particles and Antiparticles
Conceptual 27 02
53:05, highSchool, numeric, < 1 min, wordingvariable.
What is the electric charge of an antiproton?
Conceptual 27 06
53:05, highSchool, numeric, < 1 min, ﬁxed.
A proton and an antiproton, both at rest
with respect to one another, mutually annihilate into two gamma rays.
How much energy is produced in this annihilation?(Hint: How are mass and energy
related to one another?) 386 4. small radius; larger centripetal acceleration
Conceptual 27 Q03
53:05, highSchool, multiple choice, > 1 min,
ﬁxed.
When an electron and a positron annihilate, they form a pair of photons. Suppose a
friend told you that sometimes, instead of two
photons, the positron and electron annihilate
into a proton and a neutron.
What would then be true?
1. it is possible; charge is not conserved
2. it is impossible; charge is not conserved Conceptual 27 Q01
53:05, highSchool, multiple choice, < 1 min,
ﬁxed. 3. it is possible; charge is conserved
4. it is impossible; charge is conserved Which particleantiparticle interaction releases more energy?
1. electronpositron annihilation
2. protonantiproton annihilation
3. both have the same energy
Conceptual 27 Q02
53:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Some particle accelerators accelerate particles around in circular paths up to speeds
very close to the speed of light.
Which radius will be advantageous and
why?
1. large radius; larger centripetal acceleration
2. large radius; smaller centripetal acceleration
3. small radius; smaller centripetal acceleration 5. None of these
Holt SF 25Rev 45
53:05, highSchool, numeric, > 1 min, wordingvariable.
A photon with an energy of 2.09 GeV creates a protonantiproton pair in which the
proton has a kinetic energy of 95 MeV.
What is the kinetic energy of the antiproton? Chapter 53, section 7, Classiﬁcation of Particles
Conceptual 24 05
53:07, highSchool, numeric, < 1 min, ﬁxed.
Mesons are made from a quark and an antiquark. A particle called pimeson is made
from an up quark and an antidown quark.
What is the charge of this particle?
Conceptual 27 03
53:07, highSchool, numeric, > 1 min, ﬁxed.
A hadron called the sigma particle is made
from two down quarks and one strange quark.
What is the charge of the sigma particle?
Conceptual 27 04
53:07, highSchool, multiple choice, < 1 min,
ﬁxed.
Are any leptons made of quarks?
1. No; leptons are distinct from quarks.
2. Yes; leptons are point particles.
3. Yes; leptons have fractional electric
charge.
4. No;
charge. leptons have fractional electric 5. None of these 387 Chapter 53, section 15, The Eightfold Way
Apparent brightness of Jupiter
53:15, highSchool, numeric, > 1 min, normal.
What is the apparent brightness of the Sun
as seen on Jupiter?
Jupiter is 5.2 times farther from the Sun
than the Earth. Assume apparent brightness
of the sun seen at Earth is 1300 W/m2 .
Luminosity of the Sun
53:15, highSchool, numeric, > 1 min, normal.
Part 1 of 2
The instensity that the rate energy reaches
the Earth from the Sun (the “solar constant”)
is about 1300 W/m2 .
a) What is the apparent brightness of the
Sun?
Part 2 of 2
b) What is the absolute luminosity of the
Sun?
Assume the distance between the earth and
the Sun is 1.5 × 1011 m. 388 Chapter 53, section 16, Quarks
Conceptual 27 Q04
53:16, highSchool, numeric, < 1 min, wordingvariable.
How many quarks are there in a helium4
nucleus?
Conceptual 27 Q05
53:16, highSchool, multiple choice, < 1 min,
ﬁxed.
A neutron is made of three quarks.
Is it possible that two up quarks and a down
quark could make a neutron?
1. No; a neutron has no electric charge.
2. Yes; a neutron has an electric charge of
+1.
3. No; a neutron has electric charge of +1.
4. Yes; a neutron has no electric charge.
5. None of these
Holt SF 25Rev 42
53:16, highSchool, numeric, > 1 min, ﬁxed.
Part 1 of 2
Disregard binding energies and estimate
the mass of the u quark from the masses of
the proton and neutron.
Part 2 of 2
Disregard binding energies and estimate the
mass of the d quark from the masses of the
proton and neutron. 389 Chapter 54, section 5, The Cosmic Connection
Conceptual 29 01
54:05, highSchool, numeric, < 1 min, normal.
Part 1 of 2
In February 1987, a supernova was seen
to explode in the Large Magellanic Cloud,
a small galaxylike structure near the Milky
way galaxy. The supernova was about 170000
lightyears from Earth.
How far away was this explosion?
Part 2 of 2
If it were somehow possible for you to drive
your car along some steller highway in the
sky to the location of this explosion, how long
would it take you to get there, assuming you
drove at 100 km/h?
Conceptual 29 02
54:05, highSchool, numeric, < 1 min, ﬁxed.
Using the Sun as a standard candle, calculate the distance from the Sun to Venus if the
energy detected per square meter on Venus is
2.89 kW/m2 . The energy emitted by the Sun
is 4.24 × 1023 kW.
Conceptual 29 03
54:05, highSchool, numeric, < 1 min, ﬁxed.
Suppose that you observe a Cepheid variable to have a period of about 100 days and,
hence, a luminosity of 6.4 × 1028 W.
Suppose also that the amount of light you
get from that star corresponds to an energy
ﬂow of about 2 × 10−14 W/m2 at the location
of your telescope.
How far is that star from Earth?
Conceptual 29 04
54:05, highSchool, numeric, < 1 min, normal. 390 km
,
s · Mpc
what is the approximate velocity of a galaxy
10 Mpc away?
Assume a Hubble constant of 70 Conceptual 29 06
54:05, highSchool, numeric, < 1 min, normal.
If a galaxy is 700 Mpc away, how fast is it
receding from us?
Conceptual 29 07
54:05, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
An observer on one of the raisins in our
breaddough analogy measures distances and
velocities of neighboring raisins as follows
Distance Velocity
0.5 cm 1.02 cm/h
0.9 cm
2 cm/h
1.4 cm 2.9 cm/h
2.1 cm 4.05 cm/h
3 cm
5.9 cm/h
3.4 cm 7.1 cm/h
Plot the data on a graph and estimate the
Hubble constant for the raisins.
1. 2 /h
2. 3 /h
3. 4 /h
4. 5 /h
5. 6 /h
6. 7 /h
Part 2 of 2
Estimate the time that elapsed since the
dough started rising. How many kilometers are in 2 parsec?
Conceptual 29 05
54:05, highSchool, numeric, < 1 min, normal. Conceptual 29 09
54:05, highSchool, numeric, < 1 min, ﬁxed.
Part 1 of 2
Some theories say that during the inﬂama Chapter 54, section 5, The Cosmic Connection
tory period, the scale of the universe increased
by a factor of 1050 . Suppose your height were
to increase by a factor of 1050 .
How tall would an average person of 1.5
meters tall be?
Part 2 of 2
The observable universe is roughly 30 billion
light years across.
What fraction of the universe would your
height be? 391 Conceptual 29 Q02
54:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If the universe is closed, what will a future
Hubble see when he looks through a telescope
during the period of contraction?
1. blueshift
2. redshift Conceptual 29 10
54:05, highSchool, numeric, < 1 min, ﬁxed.
Suppose a proton (diameter about 10−13
cm) were to inﬂate by a factor of 1050 .
How big would it be?
Conceptual 29 11
54:05, highSchool, numeric, < 1 min, normal. 4. None of these
Conceptual 29 Q03
54:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose that scientists were able to travel
to a diﬀerent universe. The ﬁgure shows
a distanceversusvelocity graph for galaxies
measured in two universes. Conceptual 29 Q01
54:05, highSchool, multiple choice, < 1 min,
ﬁxed. y Why does the Earth seem to be at the
center of the Hubble expansion? Velocity How fast is a galaxy 5 billion lightyears
from Earth moving away from us? 3. All of these 1. Galaxies in every direction are moving
away from the Earth according to the same
Hubble constant. Our
universe
New
universe
Distance x Which universe is older? 2. Galaxies in every direction are moving toward the Earth according to the same Hubble
constant. 1. Our universe 3. Galaxies in every direction are moving
away from the Earth according to diﬀerent
Hubble constants. 3. Both are of the same age 4. Galaxies in every direction are moving toward the Earth according to diﬀerent Hubble
constants.
5. None of these 2. New universe Conceptual 29 Q04
54:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If a life form on a planet in a distant galaxy
measured the Hubble constant from its loca Chapter 54, section 5, The Cosmic Connection
tion, how would it compare to the value measured from Earth? (Assume the same unit of
measuremeant is used.) 392 54:05, highSchool, numeric, < 1 min, ﬁxed. Conceptual 29 Q07
54:05, highSchool, multiple choice, < 1 min,
ﬁxed. Our galaxy moves relative to the blackbody
background radiation with a speed of roughly
300 km/s.
By how much is the frequency of this radiation shifted due to the movement in the
direction towards the radiation at the peak
frequency of the radiation? In the direction
away from the radiation at this same peak frequency? It is possible to subtract the eﬀect of
the motion because its eﬀect can be found for
any direction. If the universe were expanding more rapidly
that it presently is, the Hubble constant will Cosmology 08
54:05, highSchool, numeric, < 1 min, normal. 1. same
2. higher
3. lower We deﬁne the ratio 1. increase. Y= 2. decrease.
3. remain the same.
Conceptual 29 Q08
54:05, highSchool, multiple choice, < 1 min,
ﬁxed.
If all that you knew was the energy per
square meter that the Sun radiated on the
surface of the Earth, could you determine the
distance from the Sun to Earth? MHe
.
MH + MHe This quantity is measured to be about 0.25.
Neglect the binding energy of the nuclei involved as well as the diﬀerence between neutron and proton masses in order to express Y
in terms of the proton mass and the numbers
of helium and hydrogen nuclei in the universe;
you should ﬁnd that the proton mass cancels
from the expression.
Solve the equation you come up with in
order to ﬁnd the ratio of the number of helium
nuclei to the number of hydrogen nuclei. 1. Yes; this is all information you need.
2. No; more information is necessary.
Conceptual 29 Q09
54:05, highSchool, multiple choice, < 1 min,
ﬁxed.
Galaxies moving towards us are called
1. redshifted
2. blueshifted
2. None of these
Cosmology 07 Cosmology 14
54:05, highSchool, numeric, < 1 min, normal.
We deﬁne
Ω = ρ/ρc
and
Ω(t) = Ω(t0 )
Ω(t0 ) + (1 − Ω(t0 )) (R/R0 ) If Ω(t0 ) = 0.2 (t0 is now), what was Ω(tx ),
where tx is the time the matter dominated
epoch started, about 105 yr? Use the result
that the radius of the universe has increased
by a factor of 2000 since then.
Galaxy distance from receding speed Chapter 54, section 5, The Cosmic Connection
54:05, highSchool, numeric, > 1 min, normal.
Estimate the distance of a galaxy in units
of light years which is moving at a speed 0.1 c
away from us.
Assume H = 80 × 103 m/s/Mpc.
Galaxy speed 02
54:05, highSchool, numeric, > 1 min, normal.
Estimate the distance of a galaxy in units
of light years which is moving at a speed 0.1 c
away from us.
Assume H = 80 × 103 m/s/Mpc.
Galaxy speed
54:05, highSchool, numeric, > 1 min, normal.
Part 1 of 2
Based on the relativistic Doppler shift formula:
1+ v
λ
c
,
=
λ
1− v
c estimate the speed of a galaxy, if the wavelength for the hydrogen line at 434 nm is
measured on Earth as being 610 nm. Part 2 of 2
Estimate the distance of this galaxy from us.
Assume H = 80 × 103 m/s/Mpc.
Galaxy speed from red shift
54:05, highSchool, numeric, > 1 min, normal.
Based on the Doppler shift formula:
λ
=
λ 1+
1− v
c
v
c , estimate the speed of a galaxy, if the wavelength of the hydrogen line, which is 434 nm
on earth, is now shifted to 610 nm as it is
emitted from the galaxy.
How far away
54:05, highSchool, numeric, > 1 min, normal.
A star exhibits a parallax of 0.28 seconds of
arc. 393 Assume 1 parsec(pc) = 3.26 ly, where parsecs are parallax angles in seconds of arcs.
How far away is it?
Schwarzschild radius of a star
54:05, highSchool, numeric, > 1 min, normal.
Determine the Schwarzschild radius of a
star comparable to our Sun with a mass 1.99 ×
1030 kg.
Assume G = 6.67 × 10−11 in SI units. Chapter 54, section 6, Cosmic Background Radiation
Conceptual 29 Q05
54:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Suppose that a new experiment showed
that the wavelength of the cosmic background
radiation were slightly shorter than its previosly measured value.
How would that change our estimate of the
average temperature of the universe?
1. The average temperature will be higher
2. The average temperature will be lower
3. The average temperature will remain the
same
Conceptual 29 Q06
54:06, highSchool, multiple choice, < 1 min,
ﬁxed.
Why cannot nuclei or atoms form during
enormously high temperatures?
1. The energy of collisions between particles
is much greater than the binding energy of
atoms or nuclei.
2. The energy of collisions between particles
is much less than the binding energy of atoms
or nuclei.
3. The energy of collisions between particles
is equal to the binding energy of atoms or
nuclei.
4. None of these 394 Chapter 54, section 8, The Big Bang
Cosmology 06
54:08, highSchool, numeric, > 1 min, normal.
How much time will have elapsed since the
big bang when the temperature of the background blackbody radiation is dominated by
radiation with wavelengths around 1 m? 395 ...
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This note was uploaded on 02/26/2012 for the course PHYSICS 302K taught by Professor Irenepolycarpou during the Spring '09 term at University of Texas at Austin.
 Spring '09
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