This exam consists of 29 questions; true-false questions are worth 2
points each, three-choice multiple choice questions are worth 3 points
each, five-choice multiple choice questions are worth 6 points each.
The maximum possible score is 98. When the exam was given, the mean was
63.0; the median was 65. Click here to see the formula sheet that came with the exam.
What is the net electric force on q ?
(a) toward the conductor
(b) toward the insulator
The drawing shows two charges q1 and q2
fixed to a circle. At the center of the circle they produce a net
electric field that is directed along the vertical axis.
The charges q1 and q2 must have the same
(a) |q1| > |q2|
(b) |q1| = |q2|
(c) |q1| < |q2|
A uniform electric field E = 35 N/C is directed upward as
shown in the figure. Consider Wac the work YOU would
do to move a positive charge from point a to point c.
(a) Wac > 0
(b) Wac = 0
(c) Wac < 0
(a) |Wac| < |Wbc|
(b) |Wac| = |Wbc|
(c) |Wac| > |Wbc|
(a) Vac = 0
(b) Vac = 35 volts
(c) Vac = 50 volts
A point charge, Q = +9 nC, is placed at the center of a hollow
conductor that is electrically neutral.
Determine the magnitude of the electric field at point A given
that the distance between the point charge Q and point A is
dA = 5 cm.
(a) EA = 0
(b) EA = 8.1 ´103 N/C
(c) EA = 32 ´103 N/C
(a) EB = 0
(b) EB = 8.1 ´103 N/C
(c) EB = 32 ´103 N/C
Two small spheres, A and B, are on a wedge, where L = 2 m. Sphere A is
held fixed at the top of the wedge, while sphere B is fixed at a
distance d1 = 50 cm from A. The two spheres have charges,
QA = -3 µC and QB = +3 µC.
There is a point along the ramp between points A and B where the
electric field due to these two charges is zero.
(a) Sphere B will not move.
(b) Sphere B will roll down, away from A.
(c) Sphere B will roll up, towards A.
Consider a regular cube with sides of length d = 1 m and positive point
charge +Q in all corners except for one which has a negative point
charge -Q. The distance from any corner to the center of the cube is r
= 0.866 m.
What is the magnitude of electric field at the center of the cube?
(a) |E| = 0
(b) |E| = 1 k Q / r2
(c) |E| = 2 k Q / r2
(d) |E| = 6 k Q / r2
(e) |E| = 7 k Q / r2
(a) V = 0
(b) V = 1 k Q / r
(c) V = 2 k Q / r
(d) V = 6 k Q / r
(e) V = 7 k Q / r
How much work would YOU have to do to assemble these point charges
from far away, to the distribution shown here?
(a) W = -15 ´ 10-8 J
(b) W = -9 ´ 10-8 J
(c) W = 0
(d) W = 9 ´ 10-8 J
(e) W = 15 ´ 10-8 J
(a) 49 V
(b) 3.8 V
(c) 0 V
(d) -3.8 V
(e) -49 V
Three capacitors (C1 = C2 = 6 µF,
C3 = 3µF), two resistors (R1 = 10 W , R2 = 20 W), and a battery (V = 9 volts) are connected as
shown. Initially, the switch is open.
At t = 0, the switch is
closed. What is the magnitude of I1 the current flowing
through the resistor R1 just after the switch is closed?
(a) I1 = 1.15 A
(b) I1 = 0.90 A
(c) I1 = 0.30 A
(a) Q2 = 27 µC
(b) Q2 = 54 µC
(c) Q2 = 81 µC
(a) t = 30 µs
(b) t = 60 µs
(c) t = 120 µs
For this circuit, which one of the following equations is not valid?
(a) +E1 + R1I1 + I2R2 - E2 = 0
(b) +E1 + (R1/2)I1 - R3I3 + E3 = 0
(c) +E2 - R2I2 - R3I3 + E3 = 0
(a) I1 + I2 + I3 = 0
(b) I1 - I2 + I3 = 0
(c) I1 + I2 - I3 = 0
(a) point a
(b) point b
(c) point c
Six resistors shown all have the same resistance of 10 W.
Compare I2, the current through R2, with
I5, the current through R5.
(a) I2 > I5
(b) I2 = I5
(c) I2 < I5
(a) V5 > V6
(b) V5 = V6
(c) V5 < V6
(a) 0.32 W
(b) 1.81 W
(c) 2.9 W
(d) 4.6 W
(e) 7.3 W
(a) Q1 > Q2
(b) Q1 = Q2
(c) Q1 < Q2