This exam consists of 27 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 107. When the exam was given, the mean
was 85.4; the median was 87. Click here to see
of the formula sheet that came with the exam.
A chamber is filled with a uniform magnetic field B with
direction as shown (into the paper). Three particles X, Y and Z are
produced near the center of the region. Parts of their tracks through
the chamber are shown in the figure. The tracks lie in the plane of the
The charge carried by particle X is
(a) |vX| > |vY|
(b) |vX| = |vY|
(c) |vX| < |vY|
(a) Z has a smaller mass than either X or Y.
(b) Z is moving faster than either X or Y.
(c) Neither of the above – there is insufficient information.
(a) The fields due to X and Y are in opposite directions so there is no clear answer.
(b) Both the fields due to X and Y subtract from the external magnetic field.
(c) Both the fields due to X and Y add to the external magnetic field.
A single loop of conducting wire of radius 15 cm is immersed in a
uniform magnetic field of 0.3 tesla. The direction of this field is
parallel to the axis of the loop. The field is turned off in 1.5 s
(that is, it goes from full strength to zero tesla in 1.5 s). .
What is the magnitude of the average induced emf during the
time the field is being turned off?
(a) 1.4 × 10-2 V
(b) 1.9 × 10-2 V
(c) 0.20 V
(d) 0.35 V
(e) 5.0 V
(a) X more than Y
(b) X the same as Y
(c) X less than Y
For a public performance of a tight-rope walker, two parallel cables
are stretched between two high platforms. The figure shows the two
cables in perspective as seen from one of the platforms. The performer
is to traverse the distance on cable 1. However, a gust of wind
makes her fall, in the direction of cable 2. The distance
between the cables is r = 3 meters for their full length
so, when she falls, the hands of the walker would narrowly miss
cable 2. However, you happen to carry a very powerful 12
V battery with you, giving you a chance to rescue the performer.
An attractive force between the wires is required to move cable
2 in the direction of the falling walker. Which way do you
connect the plus (+) and minus (–) terminals of your battery to the ends
of the wires in the cables?
(a) + to A, C; – to B, D
(b) + to A, D; – to B, C
(c) + to B, D; – to A, C
(a) 9 × 10-4 A
(b) 0.01 A
(c) 6 A
(d) 358 A
(e) 12247 A
(a) 0.12 A
(b) 1200 A
(c) 14400 A
The phasor diagram to the right yields information on a particular
series RLC circuit. It is only partially labeled, but you should
know from examining it the proper quantity that is referred to by each
number, given in ohms, in the drawing.
At the instant shown, the generator voltage is zero.
(a) Z = 24 Ω
(b) Z = 36 Ω
(c) Z = 42 Ω
(d) Z = 56 Ω
(e) Z = 68 Ω
(a) f = 22 Hz
(b) f = 49 Hz
(c) f = 81 Hz
(d) f = 106 Hz
(e) f = 159 Hz
In an RLC circuit, the current is always in phase with
(a) the resistor voltage.
(b) the inductor voltage.
(c) the capacitor voltage.
(a) Φ = +78.2°
(b) Φ = +59.5°
(c) Φ = -26.2°
(d) Φ = -39.8°
(e) Φ = -62.4°
(a) Imax = 0.317 A
(b) Imax = 0.724 A
(c) Imax = 1.65 A
(d) Imax = 2.12 A
(e) Imax = 2.97 A
An unpolarized electromagnetic wave is incident at a series of
three linear polarizers, each with the polarization angle rotated at
45° with respect to the previous one.
If the initial intensity of the unpolarized light is I0,
what is the intensity I1 transmitted through the first
(a) I1 = I0
(b) I1 = I0 / 2
(c) I1 = I0 / 4
(a) only the electric field is reduced.
(b) only the magnetic field is reduced.
(c) both the electric and magnetic field are reduced.
(a) I3 = 0
(b) I3 = I0 / 2
(c) I3 = I0 / 4
(d) I3 = I0 / 8
(e) I3 = I0 / 16
(a) 0.02 A
(b) 0.2 A
(c) 1 A
(d) 2 A
(e) 20 A
A uniform magnetic field B permeates a region of space as indicated
in the shaded region of the figure below. The direction of B is into
the paper. Each of the wire loops is moving with an identical speed v,
but with velocity oriented in different directions, as indicated in the
Which of the wire loops experiences a force towards the top of the
page due to the magnetic field?
(a) X only
(b) Y only
(c) W only
(d) Z only
(e) X and W
This loop has 200 turns of wire with resistance 0.3 Ω/m. It is
turned at a steady rate and dissipates energy with a peak power of 100
W. The external magnetic field is constant and the current I flows around
the loop in the direction indicated in the figure at the instant shown.
What is the peak emf generated in the loop?
(a) 23 V
(b) 55 V
(c) 100 V
(d) 173 V
(e) 284 V
(a) clockwise (that is, AD comes out of the page at the instant shown).
(b) counter-clockwise (that is, AD goes into the page at the instant shown).