Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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The
region around a magnet in which magnetic forces can act is called the a. | magnetic
field. | c. | pole. | b. | domain. | d. | solenoid. | | | | |
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2.
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What
do you end up with if you cut a magnet in half? a. | one north-pole piece and one south-pole
piece | b. | two unmagnetized pieces | c. | two pieces, each
with a north pole and a south pole | d. | two north-pole pieces | | |
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3.
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The
magnetic effects of a bar magnet are strongest near the ____. a. | center | c. | ends | b. | top | d. | bottom | | | | |
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4.
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Any
material that attracts iron or materials containing iron is called a a. | solenoid. | c. | superconductor. | b. | magnet. | d. | semiconductor. | | | | |
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5.
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The
magnetic effects of a bar magnet are a. | evenly distributed throughout a
magnet. | b. | distributed randomly in a magnet. | c. | concentrated
near the ends. | d. | None of the above | | |
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6.
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Sometimes the magnetic strip on a credit card becomes demagnetized. This strip is most
likely a(n) a. | permanent
magnet. | c. | electromagnet. | b. | temporary magnet. | d. | geomagnet. | | | | |
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7.
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If
you attach a magnet to a string so that the magnet is free to rotate, you will see that one end of
the magnet will point a. | north. | c. | east. | b. | southwest. | d. | west. | | | | |
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8.
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A
compass needle is a. | a fixed
magnet. | b. | a fixed nonmagnetic piece of metal. | c. | a magnet that is
free to rotate. | d. | a nonmagnetic piece of metal that is free to
rotate. | | |
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9.
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Magnetic poles always occur a. | alone. | c. | in threes. | b. | in
pairs. | d. | in
fours. | | | | |
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10.
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The
magnetic force will push magnets apart if you hold the a. | north poles of
two magnets close together. | b. | south poles of two magnets close
together. | c. | north pole of one magnet near the south pole of another magnet.
| d. | Both (a) and
(b) | | |
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11.
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Magnetic poles are similar to electric charges in that a. | like poles repel
and opposite poles attract. | b. | the magnetic force is equal to the electric
force. | c. | the number of magnetic domains responsible for the poles is
conserved. | d. | the mass of the magnetized particle is
conserved. | | |
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12.
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The
magnetic field around a bar magnet can be modeled by drawing a. | curved lines
from the north pole of the magnet to the south pole. | b. | curved lines
near the south pole of the magnet. | c. | straight lines from the north pole and from the south
pole. | d. | circular lines around the entire
magnet. | | |
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13.
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Whether a material is magnetic depends on the ____ in the material. a. | molecules | c. | number of
neutrons | b. | atoms | d. | number of protons | | | | |
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14.
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What
makes materials magnetic? a. | The atoms in these materials are magnetized by moving
electrons. | b. | The atoms in these materials are randomly
arranged. | c. | The atoms in a domain are arranged so that the north and south
poles of all the atoms line up. | d. | All of the above | | |
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15.
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Permanent magnets a. | cannot lose their
magnetization. | c. | have randomly
oriented domains. | b. | are difficult to magnetize. | d. | are easy to magnetize. | | | | |
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16.
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An
electric fan has an electric motor inside to change a. | kinetic energy
into electrical energy. | c. | electrical
energy into thermal energy. | b. | thermal energy into electrical
energy. | d. | electrical
energy into kinetic energy. | | | | |
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17.
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____
discovered the relationship between electricity and magnetism. a. | William
Gilbert | c. | Joseph
Henry | b. | Michael Faraday | d. | Hans Christian Oersted | | | | |
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18.
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Four
solenoids have the same number of loops. Which solenoid would produce the strongest magnetic
field? a. | the solenoid
with 1 A of current | c. | the solenoid
with 10 A of current | b. | the solenoid with 100 A of
current | d. | the solenoid
with 0.1 A of current | | | | |
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19.
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Electric motors work by placing a(n) ____ between the poles of a permanent magnet or
an electromagnet. a. | armature | c. | galvanometer | b. | electromagnet | d. | Both (a) and (b) | | | | |
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20.
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A
device that uses electromagnetic induction to convert kinetic energy into electrical energy is called
a(n) a. | transformer. | c. | commutator. | b. | generator. | d. | armature. | | | | |
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21.
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What
would induce a greater electric current in a wire? a. | adding more
loops of wire | b. | removing loops of wire | c. | pulling the
magnet out rather than pushing it in | d. | pushing the magnet in rather than pulling it
out | | |
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22.
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If
each of the following solenoids carries the same electric current, which one would produce the
strongest magnetic field? a. | a solenoid with a single loop | c. | a solenoid with 100 loops | b. | a solenoid with
10 loops | d. | a solenoid with
1,000 loops | | | | |
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Examine the magnetic field lines around the magnets below, and answer the questions
that follow:
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23.
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Which
magnet is the strongest? a. | Magnet A | c. | Magnet C | b. | Magnet
B | d. | All magnets have
the same strength. | | | | |
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24.
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Which
magnet is the weakest? a. | Magnet A | c. | Magnet C | b. | Magnet
B | d. | All magnets have
the same strength. | | | | |
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The
diagrams below illustrate magnetic domains within two metallic substances. Unshaded areas correspond
to one type of pole, and darkly shaded areas correspond to the opposite type of
pole.
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25.
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Which
substance is magnetized? a. | A | c. | Both A and B | b. | B | d. | Neither A
nor B | | | | |
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Completion
Complete each sentence or
statement.
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26.
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All
magnets have two ____________________ where the magnetic effects are
strongest.
(poles or inductors)
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27.
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Within an object are tiny magnetic ____________________ that can be either aligned or
misaligned. (remains or domains)
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28.
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____________________ magnets retain their magnetic properties well but are difficult
to magnetize. (Temporary or Permanent)
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29.
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A(n)
____________________ converts kinetic energy into electrical energy. (electric motor or
generator)
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30.
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The
interaction between electricity and magnetism is called ____________________. (electromagnetism or
electromagnetic induction)
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31.
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An
____________________ changes electrical energy into kinetic energy. (electric motor or
electromagnet)
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32.
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A(n)
____________________ is a coil of wire that produces a magnetic field when it is carrying an electric
current. (solenoid or electric motor)
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33.
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Electric motors use ____________________ current.
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34.
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A
loop or coil of wire that rotates in an electric motor is a(n) ____________________.
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35.
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A
device used to measure current through the interaction of an electromagnet and a permanent magnet is
called a(n) ____________________.
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EXTRA CREDIT
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36.
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Name
three properties of magnets.
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37.
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Suppose you have two bar magnets. One has its north and south poles marked, but the
other one does not. Describe how you could use the first magnet to identify the poles of the second
magnet.
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38.
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Name
the metals used to make ferromagnets.
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39.
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How
are temporary magnets different from permanent magnets?
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40.
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Why
are auroras more commonly seen in places like Alaska and Australia than in places like Florida and
Mexico?
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