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 119.
The exam period was 90 minutes; the mean score was 91.6; the median was
93. Click here to see page1
page2 of the formula sheet that came
with the exam.
Which one of the three diagrams given below shows the correct
equipotential contours associated with this dipole?
(a) EA < EB
(b) EA = EB
(c) EA > EB
With the battery still connected, the thick conducting slab shown at the
right is placed symmetrically between the two plates. What is the
effect on the capacitance C?
(a) C increases.
(b) C remains the same.
(c) C decreases.
A positive point charge +Q0 is located at point
P a distance d from a large thin sheet with uniform
positive charge density σo. A
cylindrical Gaussian surface encloses the +Q0 charge
and a portion of the sheet as shown.
Let Φo represent the outward flux
through the curved side wall (the barrel) of the Gaussian surface.
Which one of the following relations is correct?
(a) Φo > 0
(b) Φo = 0
(c) Φo < 0
Which of the following describes how the magnitude of the net
flux through the left end cap changes when the new charge is
(a) | Φafter | > | Φbefore |
(b) | Φafter | = | Φbefore |
(c) | Φafter | < | Φbefore |
Two charged rods, each with positive net charge Q0, are
held in place as shown in the top view diagram below.
A small positive test charge q0 travels from
point A to point B along the circular arc shown. The work
done on the charge by the electric field is
(a) | vA | > | vB |
(b) | vA | = | vB |
(c) | vA | < | vB |
Three thick conducting infinite planes are oriented perpendicular to
the x axis, and placed at the positions given in the figure
below. Each plane carries a net charge, as indicated in the legend.
A negatively charged object placed at x = +4 cm and
released would experience a force in the positive x
(a) 1 region
(b) 3 regions
(c) 5 regions
(a) Ex = 0
(b) Ex = 3.39 × 105 N/C
(c) Ex = 7.58 × 105 N/C
(d) Ex = 11.5 × 105 N/C
(e) Ex = 14.6 × 105 N/C
(a) σL = -6 μC/m2
(b) σL = -3 μC/m2
(c) σL = 0
(d) σL = 3 μC/m2
(e) σL = 6 μC/m2
Consider an infinite line with charge density λ0 =
+3 μC/m, shown in the center of the figure below. Concentric with
the line is a hollow thick-walled cylinder (shaded), made of conducting
material. The hollow cylinder carries a charge per unit length of
λ = -3 μC/m. Finally, a thin nonconducting cylindrical shell
is concentric with the other two objects, and carries a charge per unit
length of λc = +6 μC/m. The dimensions of the
objects are shown in the figure; all three have infinite length.
What is the surface charge density σb on the outer
surface of the thick conducting shell?
(a) σb > 0
(b) σb = 0
(c) σb < 0
(a) E = 0.54 × 106 N/C
(b) E = 1.23 × 106 N/C
(c) E = 3.15 × 106 N/C
(d) E = 5.57 × 106 N/C
(e) E = 7.14 × 106 N/C
Three massive charged balls are positioned as shown in the figure
below. A frictionless rod running along the x axis constrains
the motion of Ball #3 to slide along this axis. Ball #1 and Ball #2 are
fixed on the y axis at + 4 cm and -4 cm, respectively. Ball #3
is initially located at x = 8 cm and is held fixed.
How much total energy is required to assemble these Balls into their
initial positions assuming they all start off infinitely far away?
(a) Utotal = -3.11 J
(b) Utotal = -1.59 J
(c) Utotal = 0
(d) Utotal = 2.34 J
(e) Utotal = 8.94 J
(a) eventually come to rest at the origin.
(b) oscillate back and forth along the x axis about the origin.
(c) fly off to negative infinity along the x axis.
(a) V(0) = 0
(b) V(0) = 0.94 × 105 J/C
(c) V(0) = 2.15 × 105 J/C
(d) V(0) = 5.63 × 105 J/C
(e) V(0) = 7.42 × 105 J/C
(a) Fx = -11.5 N
(b) Fx = -18.1 N
(c) Fx = -24.4 N
(d) Fx = -30.7 N
(e) Fx = -39.5 N
A conducting sphere of radius a = 20 cm carries a charge of +6
μC. Concentric with this sphere is a non-conducting spherical shell
with an inner radius of b = 70 cm and an outer radius of c
= 80 cm. This shell carries a charge of -6 μC, distributed uniformly
throughout the material of the shell.
As one moves from a position very far from these two objects to a
point just outside the nonconducting shell, the electric potential
(c) stays the same.
(a) Wcb > 0
(b) Wcb = 0
(c) Wcb < 0
(a) | ΔVab | = 7.1 × 105 V
(b) | ΔVab | = 5.9 × 105 V
(c) | ΔVab | = 3.3 × 105 V
(d) | ΔVab | = 1.9 × 105 V
(e) | ΔVab | = 0
(a) F = 0
(b) F = 2.31 N
(c) F = 3.58 N
(d) F = 5.06 N
(e) F = 7.45 N
Three capacitors are connected as shown in the figure below. The
gaps between the plates of all three capacitors are filled with air
(κ = 1.0), giving the capacitance values listed in the figure. A
constant potential difference of 6 V is maintained between points A and
B on the circuit.
What is the magnitude of the charge Q2 on each of
the plates of capacitor C2?
(a) Q2 = 24 μC
(b) Q2 = 12 μC
(c) Q2 = 6 μC
(d) Q2 = 3 μC
(e) Q2 = 2 μC
(a) Utot = 22.2 μJ
(b) Utot = 33.7 μJ
(c) Utot = 44.5 μJ
(d) Utot = 55.3 μJ
(e) Utot = 66.9 μJ
(a) V3 = 1.78 V
(b) V3 = 2.60 V
(c) V3 = 3.43 V
(d) V3 = 4.04 V
(e) V3 = 4.85 V
(a) | ΔU2 | = 76.4 μJ
(b) | ΔU2 | = 158 μJ
(c) | ΔU2 | = 267 μJ
(d) | ΔU2 | = 378 μJ
(e) | ΔU2 | = 480 μJ