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 97.
The exam period was 75 minutes; the mean score was 60.6; the median was
61. Click here to see page1
page3 of the formula sheet that came
with the exam.
Some helpful information: • A reminder about prefixes: p
(pico) = 10-12; n (nano) = 10-9; μ (micro) =
10-6; m (milli) = 10-3; k (kilo) =
10+3; M or Meg (mega) = 10+6; G or Gig (giga) =
In this diagram, a power supply causes current to flow through the
solenoid in the direction shown (down on the visible side, upward in the
back). The solenoid has radius R = 10 cm and length L =
40 cm along its axis. The single loop surrounding the solenoid has a
resistance of 40 Ω and a radius of 24 cm.
How many turns of wire must there be if a current of 4 A will produce
a magnetic field B = 0.02 T within the solenoid?
(a) 5.3 × 106 m/s
(b) 8.8 × 106 m/s
(c) 1.3 × 107 m/s
(a) same direction as current in the solenoid
(b) direction opposite to the current in the solenoid
(a) 0.011 mA
(b) 0.029 mA
(c) 0.085 mA
(d) 0.17 mA
(e) 0.23 mA
(a) As the charge enters the field, the field does positive work on it.
(b) As the charge enters the field, the field does negative work on it.
(c) As the charge enters the field, the field does no work on it.
The diagram shows a uniform magnetic field directed out of the page. It
is confined to the region within the dashed line. At t = 0, a
rectangular wire loop moving upward in the plane of the page just begins
to enter the magnetic field. It takes 15 ms for the loop to enter the
field completely, and an additional 90 ms for the loop to begin to exit
the field at the top. If needed, external forces will be applied to
maintain constant velocity.
At time t = 10 ms, in which direction does the current in the
(a) There is no current flow at that time.
(b) The current flows clockwise.
(c) The current flows counter-clockwise.
(a) There is no magnetic force on that edge at that time.
(b) The magnetic force acts downward along the page.
(c) The magnetic force acts upward along the page.
(d) The magnetic force acts rightward along the page.
(e) The magnetic force acts leftward along the page.
(a) There will be no forces acting on the loop as it leaves the
(b) There will be a magnetic force acting on the loop as it leaves the
field, but its direction does not depend on the direction of the
(c) The direction of magnetic force acting on the loop as it leaves the
field will depend on the direction of the magnetic field.
In the RLC circuit shown, R = 220 Ω, C = 4.7 μF,
and L = 33mH. A function generator applies an alternating
voltage of frequency f = 640 Hz. Measurements reveal that the
peak voltage across the resistor is 6 V.
What rms voltage is measured across the inductor?
(a) 0.12 V
(b) 0.8 V
(c) 2.6 V
(a) The function generator voltage leads the current.
(b) The function generator peaks after the current.
(c) The function generator voltage and the current peak at the same time.
(a) 0.04 W
(b) 0.08 W
(c) 0.14 W
(d) 0.28 W
(e) 0.56 W
(a) 2.3 × 10-6 C
(b) 4.8 × 10-6 C
(c) 6.8 × 10-6 C
A generator consists of 19 rectangular loops of wire wound on a
rectangular frame of width 5 cm and height 20 cm. This frame -- and the
loops on it -- are rotated at a constant rate in a 0.09 T magnetic
field, making 18 rotations per second. This generator delivers current
to a 22 Ω resistor.
At a certain instant in time, you measure the electromotive force to
be zero. How much later is the electromotive force equal to its peak
(a) 0.014 sec
(b) 0.028 sec
(c) 0.042 sec
(a) 9 × 10-4 T m2
(b) 4.5 × 10-3 T m2
(c) 2 × 10-2 T m2
(d) 9 × 10-2 T m2
(e) 0.45 T m2
(a) 9.2 × 10-5 Nm
(b) 3.5 × 10-4 Nm
(c) 1.5 × 10-3 Nm
(d) 0.019 Nm
(e) 0.033 Nm
(a) Increasing the resistance makes it easier to rotate the
(b) Increasing the resistance has no effect on how easy it is to keep it
(c) Increasing the resistance makes it harder to keep the generator
(a) 1120 Ω
(b) 720 Ω
(c) 460 Ω
(d) 300 Ω
The phasor diagram pertains to an RLC circuit connected to a function
generator. What can we say about the function generator voltage at the
(a) The function generator voltage is decreasing.
(b) The function generator voltage is at its peak.
(c) The function generator voltage is increasing.
(a) The average power would increase.
(b) The average power would decrease.
A metal bar slides leftward across two parallel metal tracks (separated
by = 14 cm) at speed v = 0.44 m/s. A magnetic field B =
0.1 T is perpendicular to the page. A current I = 0.6 mA flows
downward through the resistor.
Does the field point into the page or out of the page?
(a) into the page
(b) out of the page
(a) 0.01 Ω
(b) 0.1 Ω
(c) 1 Ω
(d) 10 Ω
(e) 100 Ω
The top and middle wires carry current I = 50 mA to the right;
the bottom wire carries I = 50 mA to the left. The separation
L = 11 cm.
An electron moves rightward, just above the top wire and parallel to
it. What is the direction of the magnetic force acting on that
(a) out of page
(b) into page
(c) upward along page
(d) downward along page
(e) There is no magnetic force on it.
(a) 6.8 × 10-9 N upward
(b) 2.3 × 10-9 N upward
(d) 2.3 × 10-9 N downward
(e) 6.8 × 10-9 N downward