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Physics 122B Exam 1
Autumn 2010 October 14, 2010
Printed Name Seat Number
last ﬁrst
I certify that the work I shall submit is my own creation, not copied from any source, and
that I shall abide by the examination procedures outlined below.
Name
Student ID
last
Score
first
+y
Question I. Line of Charge (27 pts total)
P
Consider a total charge Q > 0 spread uniformly over a
thin rod of length L as shown. The rod lies along the xaxis and is centered at the origin. Point P is on the + yaxis a di
Chapter 9
Rotation
Conceptual Problems
1
Two points are on a disk that is turning about a fixed-axis through its
center, perpendicular to the disk and through its center, at increasing angular
velocity. One point on the rim and the other point is halfway
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II.
Score_
[10 pts total] Based on your experience in Lab.
Neutral Teflon (insulating) and neutral
aluminum (conducting) rods are suspended
by two insulating strings. Two people hold
the strings as shown.
12. [3 pts.] The Te
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III) Lecture long answer [25 points total] (Show all of your work.)
An extremely long cylinder with radius R1 is uniformly charged throughout with a volume charge
density 1 . Give your answers in terms of the variables
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III) Lecture multiple choice (18 questions)
a)
+
+
1
+
2
+
+
+
+
13. [5 pts.] Two initially uncharged metallic spheres are in contact
and are resting on insulating tables. You bring a positively
charged insulating rod n
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IV.
Score_
[20 points total] This question consists of two unrelated parts, A and B.
A box sits on the ground on a calm, windless day. Willa moves to
the right at half the speed of sound relative to the ground, as shown.
(vs
1
1.1
Multiple Choice Solutions: Winter 2015
122 Exam 1
Problem 1
First, lets find the Electric Field at P from Q2 . Using the formula E = kq
r2
we get 899000 N/C downward.
Now, lets find
the Electric Field at point P from Q1 and Q3 . Charges
Q1 and Q3 a
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I. [25 points] Rocket-ship trip. The spacetime diagram (for an Earth-based
observer) shown in the figure shows the
worldline of a rocket-ship that is at rest
on Pingus Canni (a star at rest with
respect to earth, located 15 light years
fro
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I.[10 points] Consider an infinite `current sheet
contained in the yz plane, as shown in the figure. It
consists of thin wires with a density of n =100 wires
per centimeter each carrying a current of I0 = 0.005
Amps in the direction of the
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III. Distributed charges. A spherical insulating ball of radius 2.00 cm has a net charge of 3.00
C ( 3.00 106 C ) spread uniformly on its surface.
13. (4 pts) Compute the surface charge density, , on the ball.
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IV.
[20 points total] A Gaussian surface in the shape of a rectangular
box (b b L) encloses a portion of a very large sheet, as shown at
right. Only a small portion of the sheet is shown. The sheet is an
insulator w
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III. DC Circuit Analysis. Two ideal batteries and
six resistors are connected as shown. Analyze
this circuit in the steady-state condition.
R2
I2
R1
I1
I2 R4
I3 R3
12 V
14. (3 pts) Label the current in eac
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PART I. Multiple Choice [90 points] Circle answers here and mark the Scantron Sheet
The next two questions pertain to the circuit below.
1. (5 pts) What is the current through the 100 resistor?
A.
B.
C.
D.
E.
0.8 A to
Monday, January 30, 2017
6:51 PM
Checkpoint 26.1
Rod has negative charge, cloth has positive charge
o
Doubled charge at every point for both
o
Distribution is the
same
o
o
Double at every point then that means the electric field shape is the same so the
n
Name(last, rst) student#
I. [15 points] Three electric charges are arranged as shown in the gure.
l) [5 points] If q] > 0 and the total electric force on charge q] is given by]?1 = (0, f ,0)
where f is a positive number, what are the signs of charges q2
Physics
122A&B
Lecture 5:
Electric Field & Field Vectors
First Mastering HW Due Tonight
Second HW Due Wednesday April 12
Thursday Evening Session: Tomorrow @ 5:00
Kane 210 and 220
Special Relativity Workshop
Be There!
(Unless Special Relativity is
Physics
122A&B
Lecture 2:
Special Relativity Part II
No Labs, No Tutorials (QZ) This Week
No Session Tomorrow Evening 5:00 pm
Thursday Evening April 6, 5:00 pm, Kane
Hall 210 & 220
Overview & Work Session on Relativity
Reading Quizzes Due Before Each
Physics
122A&B
Lecture 4: General Relativity,
Electric Charge & Forces
Grab a Worksheet from Table at Top of Room
Canvas Contains All Crucial Information
Contact Info For:
Lecture Professor Daryl Pedigo [email protected]
Lab Professor David Pengra dbpengra
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The circuit shown to the right consists of three resistors
with resistances R1 = 30, R2 = 60 and R3 = 50, and a
non-ideal battery with EMF = 7 Volts and internal
resistance r = 0.1. All wires are ideal. Three points on
the ci
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The circuit shown to the right consists of three resistors
with initial resistances R1 = 30, R2 = 60 and R3 =
50, and a non-ideal battery with EMF = 7 Volts and
internal resistance r = 0.1. All wires are ideal. Three
points o
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Part I: Lecture Multiple Choice [90 pts total]
Circle answers here & mark the scantron sheet.
i3
The figure to the right is related to the next five problems.
i2
The circuit shown contains three resistors, each with the same
Name Student ID Score
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Question I: Moving charges in magnetic elds
For problems 1 3 use the following: At the time t : 0 anon-relativistic electron (charge
-l.6-10'19 C, mass 9.11-10'31 kg) is moving in the +36 direction in a region of space tha
PHYS 122 A B C
Exam 1 prep
1. [3 pts] What is the direction of the electric field at point P?
A. +x
B. x
C. +y
D. y
E. some other direction (or not enough information)
Due to symmetry, the x-component of electric field at point P will be zero; since the r
Equations for Physics 122 Midterm 1:
Constants:
k=
Electric flux and Gauss Law:
1
40 ,
k = 8.99 109
0 =
Nm2
,
C2
1
4k ,
0 = 8.85
C2
1012 Nm
2,
19
e = 1.60 10
I
~ r ),
d2A n
E(~
M
M
Z
dipole moment:
=
=
d2A = r2 sin d d,
Electric Potential:
Charge densi
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Name (Print!)_
IV. Lecture Essay (25 points)
As shown in the figure, charges Q1,
Q2, and Q3 are placed at x = -a, 0,
and +a, respectively. You are told
that Q1= Q3=Q, and that Q2=-Q.
The net electric field vector at point
P is zero. Your task is to determ