Section 24.1
Magnets: Permanent and Temporary
Practice Test
1.
A nail that touches a magnet will __________.
a.
generate an electric current
b.
become polarized
c.
melt
d.
demagnetize the magnet
Hint
2.
Which of the following phenomena is NOT illustrated in Figure 24-9?
a.
The magnetic field caused by a wire is stronger closer to the wire.
b.
A current causes a magnetic field.
c.
In space, magnetic field lines point from north to south.
d.
Magnetic field lines form closed loops.
Hint
3.
Magnetic field lines travel from __________.
a.
north pole to south pole through the magnet
b.
south pole to north pole outside the magnet
c.
in a circle around the entire magnet, while never touching the magnet
d.
north pole to south pole outside the magnet
Hint
4.
The second right hand rule is used to determine the __________.
a.
direction of the magnetic field
b.
direction of magnetic force
c.
direction of current
d.
amount of current
Hint
5.
According to geologic evidence, Earth's magnetic poles __________.
a.
have switched over the years
b.
are a constant force on the planet
c.
have only recently appeared
d.
have remained the same
Hint
6.
Magnetic domains are __________ in a magnet.
a.
random
b.
scattered
c.
misaligned
d.
aligned
Hint
7.
How can you make a magnet out of a long strand of wire and an iron bar?
a.
Send a current through the bar.
b.
Spin the bar over the wire as a current runs through it.
c.
Attach the wire to either end of the bar, and send a current through it.
d.
Wrap the wire around the bar, and send a current through it.
Hint
8.
If current is reduced in an electromagnet, what happens to the magnetic field strength?
a.
it disappears completely
b.
it is reduced
c.
it increases
d.
it remains the same
Hint
9.
A south pole will __________ another south pole.
a.
repel
b.
destroy
c.
ignore
d.
attract
Hint
10.
What happens if you cut a magnet in half?
a.
you get monopoles
b.
you get two magnets
c.
you get a separate south pole and a separate north pole
d.
it becomes demagnetized
Hint
11.
In Figure 24-7, if somehow the poles on the middle magnet could suddenly be reversed, which of the following would NOT happen?
a.
The top magnet would fall slightly.
b.
The bottom magnet would stick to the one above it.
c.
The middle magnet would stick to the one above it.
d.
The middle magnet would stick to the one below it.
Hint
12.
The ___________ is proportional to the strength of the magnetic field.
a.
magnetic flux per unit area
b.
size of the magnet
c.
mass of the magnet
d.
magnetic flux
Hint
