Chapter 18
Superposition and Standing Waves.
Solutions of Selected Problems
18.1
Problem 18.8 (In the text book)
Two loudspeakers are placed on a wall 2.00 m apart. A listener stands 3.00 m from the
w
Phys. 155 Lecture 11
Magnetic Torque. Magnetic Field Production
Outline:
Review: Force on a wire.
Magnetic Torque:
= I A B;
| = I A B sin
Problems: Magnetic torque, tilted loop, deflected rod.
I
Phys. 155 Lecture 12
Magnetic Field Production, Amperes Law,
Magnetic Materials
Outline:
Demonstration: Oersted experiment, Parallel wires.
Problems: Torque, B-field of wires
Magnetic field of a cu
Phys. 155 Lecture 10
Force on a Current Carrying Conductor in B Field
Outline:
Review: Force on a moving charge
Velocity Separator E and B field effects compensated
J.J. Thomson experiment to deter
Phys. 155 Lecture 9
Magnetic Field and force on a moving charge
Outline:
Permanent magnets
Magnetic field concept
Force on a moving charge:
- Expression
- Right hand rule
Work done by force on a m
Part 2: Electric Circuits
Example solutions
Dr. Chijin Xiao
Phys155-part2-Example solutions, Xiao, 2015
1
Plancks constant
=6.63x1034 Js = 4.14x 1015 eVs
Photon energy
=
f (or ) is the frequency o
Physics
Cutnell & Johnson (9th ed.)
Chapter 19.5, 20.12, 20.13
Pages 579-583, 620-623
Phys155-Pt2-08-circuits with capacitors, C. Xiao, 2015
1
In this section of my lectures we will
be revisiting the
Physics
Cutnell & Johnson (9th ed.)
Chapter 20
Phys155-part2-07-Circuit Analysis II, C. Xiao, 2015
1
When circuits get really complex
methods learned so far will still work,
but they can take a long t
Physics
Chapter 20.6-20.8, 20.10
Pages 606-614, 615-618
Phys155-part2-05-Series and Parallel Circuits, C. Xiao, 2015
1
In this section of lectures we will be
developing the two common types of
resisto
Physics
Cutnell & Johnson (9th ed.)
Chapter 20.3
Pages 601-603
Phys155-part2-04-Ohms Law, C. Xiao, 2015
1
In this lecture we will be developing
the relationship between voltage,
current and resistance
Physics
Cutnell & Johnson (9th ed.)
Chapter 20.3
Pages 598-601
Phys155-part2-03-Resistance, C. Xiao, 2015
1
In this lecture we will be developing the
concept of resistance.
To do this we will use as a
Part 2: Electric Circuits
Dr. Chijin Xiao
Phys155-part2-01-Voltage, Xiao, 2015
1
B.Sc.,M.Sc. in Physics from University of Science and
Technology of China in Hefei, China
Dr. rer. nat. (Doctor in Natu
Physics
Cutnell & Johnson (9th ed.)
Chapter 20.1, 20.4
Pages 595-597, 601-603
Phys155-part2-02-Current and Power, C. Xiao, 2015
1
Potential difference (voltage) between two
points causes charges to mo
Current and Power
C. Xiao
Physics
Cutnell & Johnson (9th ed.)
Chapter 20.1, 20.4
Pages 595-597, 601-603
Conductor
Insulator
Semiconductor
Phys155-part2-02-Current and Power, C. Xiao, 2015
Phys155-p
Voltage source
C. Xiao
B.Sc.,M.Sc. in Physics from University of Science and
Technology of China in Hefei, China
Part 2: Electric Circuits
Dr. rer. nat. (Doctor in Natural Science) in Physics
from Ruh
Problems on force Fi from previous exams
Correct answer is (a)
A wire having a mass per unit length of 0.500 g/cm carries a 2.00-A current horizontally to the
south. What are the direction and magnitu
Problems on force Fi from previous exams
A wire having a mass per unit length of 0.500 g/cm carries a 2.00-A current horizontally to the
south. What are the direction and magnitude of the minimum magn
Additional problems for Lectures 3-4.
Torque:
A coil carries a current and experiences a torque due to a magnetic field. The value of
the torque is 80% of the maximum possible. (a) What is the smalles
Solutions to problems considered in
class
(Lectures 1-2)
Test question:
A proton traveling due west in a region that contains only a magnetic field experiences a vertically upward force (away from the
Additional problems for Lectures 5-6.
Lenz:
1. A flexible, circular conducting loop lies in a uniform magnetic field, as shown below.
The loop is pulled on opposite sides by equal forces and stretched
Solutions to problems considered in
class
(Lectures 3-4)
Solution
Given are B, I, L (length) and m
(mass) of the conductor.
How to determine the angle?
2
Solution for 2 turns loop torque
Magnitude of
Solutions to additional problems for Lectures 3-4.
Torque:
A coil carries a current and experiences a torque due to a magnetic field. The value of
the torque is 80% of the maximum possible. (a) What i
1
Faraday law of induction
Lenzs rule
2
Last time:
Motional emf
Em L V B
DC geneator
3
Example of a problem on motional emf: A bar
accelerates from the rest down the slides of length S.
There is a mag
1
1. Torque on a current-carrying
loop in magnetic field t
2. Production of magnetic field by
currents:
straight line current
2
Current-carrying loop in B field
Sum of the forces is zero, but
the loop
1
1. Production of magnetic field by currents:
current loop
solenoid
2. Amperes law
3. Magnetic materials
4. Motional emf
2
Summary of previous equations
0 I
| B |
2r
0 I1 I 2
| F |
L
2 d
3
Example