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 118.
The exam period was 90 minutes; the mean was 90.2; the median was 93.
Click here to see page1
page2 of the formula sheet that came
with the exam.
What is the voltage, V3, across
(a) 1.64 volts
(b) 2.64 volts
(c) 3.64 volts
(d) 4.36 volts
(e) 5.36 volts
(a) I1R1 +
I3R3 - V = 0
(b) V - I1R1 -
I4R4 = 0
(c) I2R2 -
I3R3 = 0
(d) I1 = I2 + I3
(e) I1R1 +
I4R4 - V = 0
Compared to the original situation, how does this change affect current
(a) I1 remains the same.
(b) I1 increases.
(c) I1 decreases.
(a) R2 = R1
(b) R2 = 2R1
(c) R2 = 4R1
Which of the following plots best shows
B·dl as a function of position along
the closed path?
The capacitor is initially uncharged and the switch is moved to
position A at time t = 0.
What is the current I1 through resistor
R1 immediately after the switch is moved to position
(a) 0.1 A
(b) 0.5 A
(c) 1.0 A
(d) 1.5 A
(e) 2.0 A
(a) 0 mJ
(b) 0.125 mJ
(c) 0.250 mJ
(d) 0.500 mJ
(e) 1.000 mJ
(a) 0 μs
(b) 12.7 μs
(c) 50.0 μs
(d) 69.3 μs
(e) 100.0 μs
A magnetic field, B= 0.8 T, is directed out of the page in a
region containing a rectangular up-side-down "U-wire" having width
W = 0.5 m, as shown. A resistor of mass m and resistance
R = 6 Ω, which is free to slide without friction on the
vertical rails, is released from rest and starts falling in the presence
of the earth's gravitational field, reaching a terminal speed v =
What is the direction of the induced current in the loop formed by
the resistor and the U-wire?
(a) 3.8 g
(b) 4.3 g
(c) 7.7 g
(d) 10.3 g
(e) 18.9 g
(a) The work per unit time done by the earth on the resistor is
equal to the power dissipated in the resistor.
(b) The work done by the magnetic field on the resistor is equal in
magnitude, but opposite in sign, to the work done by the earth on the
(c) Both of the statements above are valid.
Consider a long wire running in the vertical direction with a
rectangular loop of wire beside it as shown. Which of the following
situations would result in a clockwise induced current in the loop?
(a) A current in the long wire, directed upward, is increasing
(b) With a constant current in the long wire directed upward, the loop is
moved toward the top of the page, parallel to the long wire.
(c) The loop is held stationary and the long wire, while carrying a constant
upward current, is moved away from the loop.
(c) The loop does not rotate.
A short, straight wire segment of length l carries current
I and is oriented so that it makes an angle of 30° with the
horizontal. Point P is a distance r below the wire segment.
Which expression below is the best approximation for the magnetic
field caused by the wire segment at point P?
(a) (μoIlcos30°) / (4π2)
(b) (μoIlsin30°) / (4π2)
(c) (μoIl) / (4π2)
A long, thin wire carrying constant current I = 2 A into the
page is surrounded by a concentric cylindrical hollow wire of inner
radius a = 0.12 m, and outer radius b = 0.26 m, carrying
total current I = 4 A directed out of the page, as shown. Assume
the current in the cylindrical hollow wire is distributed uniformly over
its cross-sectional area.
At what radius is B = 0 in the region a < r
< b inside the hollow wire?
(a) 0.19 m
(b) 0.20 m
(c) 0.21 m
(d) 0.25 m
(e) The magnetic field is not zero anywhere inside the hollow wire.
(a) For radii r > b, the magnetic field is the
same as the field a distance r from the center of a long wire
carrying total current of 6 A directed out of the page.
(b) Ampere's law is valid only in highly symmetric situations, such as the
situation depicted in the diagram.
(c) The magnetic field at the point labeled C is directed out of the page.
(d) The magnitude of the magnetic field at r = a is less than
the magnitude of the magnetic field at point C (assume that the distance
from the center to point C is 3a).
(e) None of the statements above is valid.
A passenger jet is flying over Alaska in level flight at a constant
altitude h = 10 km and constant speed of v = 300 m/s,
immersed in the earth's vertically downward-pointing magnetic field of
B = 30 μT. The distance between the tips of the aircraft's
metal wings is d = 50 m.
Calculate the potential difference ε between the
aircraft's wing tips due its motion through the earth's magnetic
(a) ε = 0.0 volts
(b) ε = 0.45 volts
(c) ε = 0.90 volts
(a) the right wingtip
(b) the left wingtip
(c) neither wingtip
(a) +y direction
(b) -y direction
(c) +z direction
(a) d = 68.9 m
(b) d = 257.3 m
(c) d = 453.6 m
(d) d = 626.3 m
(e) d = 1738.9 m
(a) B = 0.5 T, in the +x direction
(b) B = 0.5 T, in the -z direction
(c) B = 0.5 T, in the +z direction
(d) B = 1.5 T, in the -y direction
(e) B = 1.5 T, in the +z direction
(a) m = 0.094 A-m2, in the -z direction
(b) m = 0.094 A-m2, in the +z direction
(c) m = 9.42 A-m2, in the -z direction
(d) m = 9.42 A-m2, in the +z direction
(e) m = 94.2 A-m2, in the +z direction
(a) τ = 0.010 A-m2, U = -0.017 J
(b) τ = 0.010 A-m2, U = 0.017 J
(c) τ = 0.017 A-m2, U = 0.010 J
(d) τ = 0.017 A-m2, U = -0.010 J
(e) τ = 0.017 A-m2, U = -0.017 J
(a) B(0,0,z=0.1m) = 0.628 × 10-7 T, -z direction
(b) B(0,0,z=0.1m) = 2.323 × 10-6 T, +z direction
(c) B(0,0,z=0.1m) = 3.678 × 10-6 T, -z direction
(d) B(0,0,z=0.1m) = 4.443 × 10-6 T, +z direction
(e) B(0,0,z=0.1m) = 8.886 × 10-6 T, +z direction