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 117.
The exam period was 90 minutes; the mean score was 95.5; the median was
99. 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) =
(d) capacitor and inductor
(e) inductor and resistor
I) Vgen(t) = VL(t) + VR(t) + VC(t)
II) Vgen,max = VL,max + VR,max + VC,max
(c) I and II
(e) none of the above
The phasor diagram for a series RLC circuit is shown here with
phasors VR, VL and
VC corresponding to the resistor, capacitor, and
inductor, respectively. Three additional phasors (A, B, and C, in
dotted lines) are included as well.
Which of these three phasors corresponds to that of the generator?
(a) The frequency is less than the resonant frequency.
(b) The frequency is the same as the resonant frequency.
(c) The frequency is greater than the resonant frequency.
If the current in the central loop is increased, in what
directions will induced currents in the top loop and the bottom loop
(a) Top - counterclockwise; Bottom - counterclockwise
(b) Top - counterclockwise; Bottom - clockwise
(c) Top - clockwise; Bottom - counterclockwise
(d) Top - clockwise; Bottom - clockwise
(e) There are no induced currents.
Assuming that all particles have the same speed, what is the ratio
R235 / R238 of the radii of the
paths taken by the two isotopes?
What is the phase angle φ associated with the generator?
A charged particle travels through two chambers as shown below. It
enters Chamber 1 from below and exits Chamber 2 from above. The
particle moves at a speed of 150 m/s. The magnetic field in Chamber 2
has a magnitude of 0.8 T.
Assuming the particle is negatively charged, what is
the direction of the magnetic field in Chamber 1?
(a) into the page
(b) out of the page
(c) to the right
(a) 2.22 C
(b) 3.49 C
(c) 6.98 C
(d) 2220 C
(e) 3490 C
(a) B1 > B2
(b) B1 = B2
(c) B1 < B2
As shown below, an RLC circuit consists of a resistor R, a variable
capacitor C, an inductor L and an AC power source generating a voltage
of V(t) = V0 sin(2π f t).
Circuit parameters R, L and V0 are fixed
at R = 50 Ω, L = 4 mH and V0 = 20
V, and the generator frequency is set to f = 5 kHz.
To what value should you change the capacitance C for the
circuit to be in resonance with the frequency f of the
(a) 2.5 × 10-7 F
(b) 7.5 × 10-3 F
(c) 8.3 F
(a) 0.5 watts
(b) 1 watt
(c) 4 watts
(d) 16 watts
(e) 256 watts
(a) 19 Ω
(b) 57 Ω
(c) 112 Ω
(d) 294 Ω
(e) 1061 Ω
(a) L2 = L1 / 4
(b) L2 = L1 / 2
(c) L2 = L1
(d) L2 = 2 L1
(e) L2 = 4 L1
A circular loop is placed in a uniform external magnetic field
B pointing into the page. The loop has resistance
The external magnetic field B is turned up slowly at a constant rate
from 0 to 1 T in 100 s. Is there a current in the loop, and if so, in which
direction does it flow?
(b) There is no current.
(a) ε is 100 times smaller.
(b) ε is 10 times smaller.
(c) ε is the same.
(d) ε is 10 times larger.
(e) ε is 100 times larger
In the circuit shown below the resistor has a resistance of 5
Ω. The solenoid has 7 turns, a length of 10 cm and a radius of 1
cm. The battery supplies 10 volts to the circuit. Assume the battery
has been connected for a long time.
Determine the value of the magnetic field B inside the solenoid after a
time long enough for the circuit to achieve its maximum current.
(a) B = 2.70 × 10-7 T
(b) B = 9.34 × 10-5 T
(c) B = 1.76 × 10-4 T
(d) B = 3.33 × 10-2 T
(e) B = 0.29 T
(a) 1.97 × 10-7 H
(b) 0.87 × 10-6 H
(c) 3.24 × 10-4 H
(d) 7.97 × 10-4 H
(e) 2.21 × 10-3 H
A rectangular loop of dimensions 3 cm × 5 cm is initially in a
region having a uniform magnetic field of B = 3 T. The loop is
being pulled out of this region into a region of no field at a rate of
v = 10 m/s.
Consider a time interval beginning when the loop is well within the
region of the magnetic field and ending when it is well into the
field-free region. Over this interval, as a function of time, which
graphs best represent the magnetic flux Φ and the induced EMF
ε in the loop?
Consider an instant during which the loop is partly out of the field
region as shown above. If the resistance of the loop is 2 Ω, what
is the magnitude of the current generated in the loop?
(a) 0.003 A
(b) 0.45 A
(c) 6.25 A
(d) 34 A
(e) There is no current generated.
(c) There is no current generated.
A single square loop of wire of side 0.2 m lies in the
x-y plane. A current I = 3 A flows around the loop
in a clockwise direction, as shown in the figure. A uniform magnetic
field B of magnitude 0.75 T points along the +x direction.
What is the magnitude of the torque τ on the loop due to
the magnetic field?
(a) τ = 0.039 N·m
(b) τ = 0.063 N·m
(c) τ = 0.090 N·m
(e) The loop does not rotate.
(a) 0 N·m
(b) 0.024 N·m
(c) 0.056 N·m
(a) M = 0.038 μH
(b) M = 0.27 μH
(c) M = 1.4 μH