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 120.
The exam period was 90 minutes; the mean was 92.0; the median was 96.
Click here to see page1
page2 of the formula sheet that came
with the exam.
This circuit has three batteries with voltages
V1, V2 and V2,
three standard resistors of resistance R1 and a light
bulb with resistance R2.
Which one of the choices listed on the right is an expression for
the magnitude of the current I in terms of
V1, V2, R1 and
(a) lower than
(b) the same as
(c) higher than
Three resistors, three capacitors, a battery and two switches are
connected in the circuit shown below. The values of all circuit
elements are given in the figure. Originally, the switches
S1 and S2 are open (as shown) and
all of the capacitors are uncharged. At time t = 0, both
switches are closed.
What is the current I1 through resistor
R1 immediately after the switches are
(a) I1 = 0 A
(b) I1 = 1.8 A
(c) I1 = 2.5 A
(d) I1 = 3.8 A
(e) I1 = 4.7 A
(a) I2 > 0
(b) I2 = 0
(c) I2 < 0 (i.e. opposite the direction shown)
(a) Q2 = 0 μC
(b) Q2 = 33 μC
(c) Q2 = 90 μC
(d) Q2 = 180 μC
(e) Q2 = 270 μC
(a) t1/e = 1200 μsec
(b) t1/e = 1500 μsec
(c) t1/e = 3000 μsec
(d) t1/e = 3600 μsec
(e) t1/e = 4800 μsec
An electron of mass m and charge q is accelerated to
the right (in the plane of the page) from rest through a potential
difference V. The electron then enters a region, defined by
x > 0, containing a uniform magnetic field.
When the electron enters the region with the magnetic field the force
on it is directed
(a) toward the top of the page.
(b) toward the bottom of the page.
(c) into the page.
(c) remains constant.
(a) T = 1.2 × 10-15 s
(b) T = 7.5 × 10-12 s
(c) T = 6.0 × 10-11 s
(d) T = 8.3 × 10-8 s
(e) T = 4.1 × 10-5 s
A rectangular wire loop of height h and width w,
centered on the origin, carries current I in the direction shown
in the figure. The angle between the positive x-axis and the
plane of the loop is θ, defined as shown in the figure
below. (When θ = 0 the loop lies in the x-z
plane.) This entire region of space is filled with a uniform external
magnetic field B pointing in the +x direction.
When θ = 60°, the force on the leg of length
h with the upward-going current is in the
(a) positive x direction.
(b) negative x direction.
(c) positive y direction.
(d) negative y direction.
(e) positive z direction
(a) |W| = 9.09 × 10-5 J
(b) |W| = 2.37 × 10-4 J
(c) |W| = 4.25 × 10-4 J
(d) |W| = 5.87 × 10-4 J
(e) |W| = 8.13 × 10-4 J
(a) does no work on the loop.
(b) does positive work on the loop.
(c) does negative work on the loop.
What is the direction of the torque on the wire carrying
I1 due to the current I2 in the
(a) in the positive y direction
(b) in the positive z direction
(c) in the negative y direction
A solid, infinitely-long, conducting rod has radius a = 15 cm
and lies along the z axis. It carries a current I = 30 A
in the +z direction. The current is uniformly distributed across
the rod. It is surrounded, at a distance b = 30 cm, by a thin
coaxial conducting shell that carries a current of the same magnitude,
but directed in the -z direction.
Find the magnitude B of the magnetic field at a distance of
10 cm from the origin.
(a) B = 2.67 × 10-5 T
(b) B = 3.52 × 10-5 T
(c) B = 4.80 × 10-5 T
(d) B = 6.15 × 10-5 T
(e) B = 7.20 × 10-5 T
(a) negative x direction
(b) negative y direction
(c) positive y direction
A rectangular wire loop of height h, width w and net
electrical resistance R lies in the x-y plane. As
shown in the figure below, there is a region of space at -1.5w
< x < 0 in which there is a magnetic field pointing in the
-z direction. In order to determine the magnitude of this field,
a student pulls the wire loop through the magnetic field region at a
constant velocity v in the +x-direction, and measures the
current I induced in the loop during this process.
If, when the leading edge, A, of the loop is located at
xA = -w, the student measures a current of 20
× 10-6 amps, what is the magnitude B of the
(a) B = 0.12 T
(b) B = 0.31 T
(c) B = 0.57 T
(d) B = 0.99 T
(e) B = 1.15 T
(c) No current flows in the loop in this situation.
The figure at right shows a circular wire loop of total resistance
R. The loop is contained within a region having a uniform
magnetic field B pointing out of the page, and is attached to a
motor that keeps it rotating around the y-axis in a clockwise
direction (when looking in the negative y-direction) at constant
angular velocity ω. The loop is initially parallel to the
x-y plane (the plane of the paper), as shown.
Which one of the following graphs best represents the EMF induced in the
loop as a function of time? (ε changes sign if the induced current changes
direction; ε = 0 is denoted on the graphs. In the initial (t = 0) position
shown in the figure above, ε is defined to be positive if it leads to
clockwise current in the loop).
(a) |ε| = 0 V
(b) |ε| = 0.0563 V
(c) |ε| = 0.125 V
(d) |ε| = 0.224 V
(e) |ε| = 0.418 V
(b) remains the same.
Three identical resistors are connected to a battery, an inductor,
and a switch as shown in the figure. (The values of all circuit
elements are given below the figure.) The switch has been open for a
very long time, and then it is closed at time t = 0.
Calculate the current delivered by the battery immediately after
the switch is closed.
(a) 0.353 A
(b) 0.706 A
(c) 0.998 A
(d) 1.22 A
(e) 1.38 A
(a) VL = 0 V
(b) VL = 6 V
(c) Neither of the above answers is correct.
(a) EL = 3.30 × 10-6 J
(b) EL = 5.62 × 10-6 J
(c) EL = 8.63 × 10-6 J
(d) EL = 1.07 × 10-5 J
(e) EL = 1.12 × 10-5 J
(a) fI = 0.0521
(b) fI = 0.0926
(c) fI = 0.158
(d) fI = 0.201
(e) fI = 0.236