Intermediate Exam III: Problem #1 (Spring 05)
An infinitely long straight current of magnitude I = 6A is directed into the plane () and located a
distance d = 0.4m from the coordinate origin (somewhere on the dashed circle). The magnetic
~ generated by th
Unit Exam IV: Problem #1 (Spring 12)
In the circuit shown we close the switch S at time t = 0. Find the current IL through the inductor
and the voltage V6 across the 6-resistor
(a) immediately after the switch has been closed,
(b) a very long time later.
Intermediate Exam III: Problem #1 (Spring 05)
An infinitely long straight current of magnitude I = 6A is directed into the plane () and
located a distance d = 0.4m from the coordinate origin (somewhere on the dashed
~ generated by this current is in the n
PHY204 UNIT EXAM 2, section 2 (Spring 2016)
Problem 1
The capacitor circuit shown is connected to a 12 V battery. Find
(a) the equivalent capacitance Ceq ;
(b) the electric charge Q4 on the 4 F capacitor;
(c) the potential energy U3 stored on the 3 F capa
PHY204 UNIT EXAM 3, section 2 (Spring 2016)
Problem 1
(a) A point charge q = 3.5 nC moves along the positive z-axis through
a uniform magnetic field B = 0.55 i T at a velocity v = 2.0 107 m/s. Find
the force Fa (all components of this vector) acting on th
Intermediate Exam III: Problem #1 (Spring 06)
Consider two infinitely long, straight wires with currents of equal magnitude
I1 = I2 = 5A in the directions shown.
Find the direction (in/out) and the magnitude of the magnetic fields B 1 and B2 at the
points
PHY204 UNIT EXAM 2, section 2 (Spring 2016)
Problem 1
The capacitor circuit shown is connected to a 6 V battery. Find
(a) the equivalent capacitance Ceq ;
(b) the electric charge Q4 on the 4 F capacitor;
(c) the potential energy U2 stored on the 2 F capac
Intermediate Exam II: Problem #1 (Spring 05)
The circuit of capacitors connected to a battery is at equilibrium.
(a) Find the equivalent capacitance Ceq .
(b) Find the voltage V3 across capacitor C3 .
(c) Find the the charge Q2 on capacitor C2 .
C3 = 3 F
Intermediate Exam II: Problem #1 (Spring 06)
The circuit of capacitors connected to a battery is at equilibrium.
(a) Find the charge Q3 on capacitor C3 .
(b) Find the charge Q2 on capacitor C2 .
12V
C 3 = 3 F
C1= 2 F
C 2 = 2 F
Solution:
(a) Q3 = C3 (12V)
EXAM ONE
02/04/2016
September 6, 2013
Physiology (function, how stuff happens) vs. Anatomy (structure)
Teleological (why) vs. mechanistic (how)
Casual Chains: _ -> _ -> _ -> etc.
Organization:
Atoms
Molecules
Cells
Tissues: group of cells with similar
Bio 242 Exam 1 Study Guide
Describe the organization of life (Cell->tissue->etc) and describe the characteristics
of each.
Cell: smallest unit of life
Tissues: organized group of cells with a similar structure and function
Organs: organized in such a way
3Mechanist Approach: To answer how something occurs using causal chains, or
cause and effect sequences.
Teleological Approach: To answer questions as to why something occurs.
Levels of Organization
Basic unit of life is the cell (also the smallest unit of
Particle Projected Perpendicular to Uniform Electric Field
A charged particle (m = 3kg, q = 1C) is launched at t0 = 0 with initial speed v0 = 2m/s in an electric field of magnitude E = 6 106 N/C as shown.
y m q 1m 1m
(a) Find the position of the pa
Electric Dipole Potential
Use spherical coordinates: V = V (r, ) independent of azimuthal coordinate . , r- - r+ (-q) q = kq Superposition principle: V = V+ + V- = k + r+ r- r- r+ Large distances (r L): r- - r+ L cos , r- r+ r2 V (r, ) k qL cos
Action and Reaction due to Coulomb Interaction
Two particles with masses m1 , m2 and charges q1 , q2 are released from rest a distance r apart. We consider the following four distinct configurations: (a) m1 = 1kg, m2 = 1kg, q1 = 1C, q2 = 1C (b) m1 =
Particles Accelerated by Uniform Electric Field
A uniform electric field E = 0.75 103 N/C exists in the box. (a) A charged particle of mass m1 = 1.9 10-9 kg is released from rest at x = 3cm, y = 0. It exits the box at x = 3cm, y = 6cm after a time
Electric Potential of Conducting Spheres (1)
A conducting sphere of radius r1 = 2m is surrounded by a concentric conducting spherical shell of radii r2 = 4m and r3 = 6m. The graph shows the electric field E(r). (a) Find the charges q1 , q2 , q3 on th
Electric Field of a Point Charge
electric charge
generates
electric field
exerts force locally
electric charge
exerts force over distance
(1) Electric field E generated by point charge q: E = k
q r ^ r2
(2) Force F1 exerted by field E on poi
Kirchhoff's Rules
Loop Rule
When any closed-circuit loop is traversed, the algebraic sum of the changes in electric potential must be zero.
Junction Rule
At any junction in a circuit, the sum of the incoming currents must equal the sum of the outg
Cylindrical Capacitor
Conducting cylinder of radius a and length L surrounded concentrically by conducting cylindrical shell of inner radius b and equal length. Assumption: L b.
: charge per unit length (magnitude) on each cylinder Q = L: magnitu
Charged Particle in Crossed Electric and Magnetic Fields (1)
Release particle from rest. Force: F = q(E + v B) dvx = -qvy B dt dvy = qvx B + qE (2) Fy = m dt Ansatz: vx (t) = wx cos(0 t) + ux , (1) Fx = m qB dvx =- vy dt m qB dvy qE = vx + dt
Hall Effect
Method for dermining whether charge carriers are positively or negatively charged. Magnetic field B pulls charge carriers to one side of conducting strip. Accumulation of charge carriers on that side and depletion on opposite side produ
Capacitor and Capacitance
Capacitor (device):
Two oppositely charged conductors separated by an insulator. The charges +Q and -Q on conductors generate an electric field E and a potential difference V (voltage). Only one conductor may be present.
Ampre's Law: Magnetic Field Inside a Toroid
Apply Ampre's law, I B d = 0 IC , to the circular Amperian loop shown.
Magnetic field inside: directed tangentially with magnitude depending on R only. Magnetic field outside: negligibly weak. Number o
Magnetic Force Application (3)
The dashed rectangle marks a region of uniform magnetic field B pointing out of the plane. Find the direction of the magnetic force acting on each loop with a ccw current I.
4 2 I 1 I 3 I B
N
I
NW W SW
NE E SE
S
Calculating the Resistance of a Wire
Uniform cross section
Length of wire: L Area of cross section: A Resistivity of material: Current density: J = Current: I = JA Voltage: V = EL Resistance: R E [A/m2 ]
Variable cross section
Cross-secti
Resistors Connected in Parallel
Find the equivalent resistance of two resistors connected in parallel. Current through resistors: I1 + I2 = I Voltage across resistors: V1 = V2 = V Equivalent resistance: 1 1 1 = + R R1 R2 I I1 1 I2 = + R V V1 V2
Power Dissipation in Resistor
Consider a resistor in the form of a uniform wire. Voltage between ends: V Va - Vb = E(xb - xa ) Displaced charge: dq = Idt
dq E xa xb
a
R
b
I
Work done by electric field E on displaced charge dq: WE = F (xb -
Resistor Problem (1)
A heating element is made of a wire with a cross-sectional area A = 2.60 10 -6 m2 and a resistivity = 5.00 10-7 m. (a) If the element dissipates 5000W when operating at a voltage V 1 = 75.0V, what is its length L1 , its resist