Practice for exam 2
1) Can a constant magnetic field set a proton at rest
into motion?
2) Which way would a compass points if you were at
the Earth’s geographic north pole?
3) Is it possible to orient a current loop in a magnetic
field so that is does not tend to rotate?
4) A charged particle moving in a magnetic field has to
follow a circular path. True or False.
5) Wires carrying currents in parallel directions attract.
True or False
6) A clockwise current loop in the plane of the page
produces a magnetic field in which direction?
7) A wire carrying current to the right is deflected
upwards by a magnetic field. What is the
direction of the magnetic field?
8) As a conducting bar moves to the left in a
magnetic field pointing into the board, which
direction does the electric field in the bar point?
9) A ring is in the plane of the page. If a magnetic
field into the page is increased in strength, What
is the direction of the induced current?
10)You can produce an induced current with a
constant magnetic field. True or False
11) If the current through an inductor is doubled, by
what factor is the stored energy changed?
12) Solenoid 1 has 20 turns/cm. Solenoid 2 has 40
turns/cm. Which solenoid has a higher
inductance?
13) A wire with current points upwards. A circular
wire is in the vertical plane to the right of the
long wire. As the long wire’s current increases,
what is the direction of the circular wire’s
induced current?
Find the magnitude and direction of the acceleration
of the square current loop of side lengths 0.2 m, if it
has a mass of 0.3kg.
6A
5A
0.1 m
Ch. 19 Number 39
Ch. 20 Number 14
Ch. 20 Number 39
Find the energy stored in the solenoid from
number 39 if the current through the solenoid
is 4 A. How much energy is stored if the
current is doubled?
As the ring moves to the right, find the
direction of the induced current as the ring is
at locations a, b, c, and d. In the shaded
region the magnetic field is out of the page.
a
b
B out
c
d