Georgia Science Grade 8

Chapter 21: Magnetism

CRCT Practice

1
What device is shown in the figure?

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A)electromagnet
B)generator
C)electric motor
D)transformer
2
Which best describes the function of this device?

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A)It transforms electrical energy into kinetic energy.
B)It transforms kinetic energy into electrical energy.
C)It increases the voltage in a circuit.
D)It produces an alternating current.
3
Which statement about the magnetic poles of the magnetic domains in a bar magnet is true?
A)They point in random directions.
B)They cancel each other.
C)They point in one direction.
D)Their orientation cannot change.
4
The shape of Earth's magnetic field is similar to the magnetic field around which of these?

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A)an electric generator
B)a bar magnet
C)an electric motor
D)a current-carrying wire
5
In which of Earth's layers is Earth's magnetic field generated?

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A)crust
B)mantle
C)outer core
D)inner core
6
Which is NOT true about an electromagnet?
A)It has north and south poles.
B)It attracts magnetic materials.
C)Its magnetic field can be turned off.
D)Its poles cannot be reversed.
7
Which produces alternating current?
A)electromagnet
B)wire coil
C)generator
D)motor
8
Which can happen when a currentcarrying wire is placed in a magnetic field?
A)The current in the wire disappears.
B)A force is exerted on the wire.
C)A current is generated in the magnet.
D)The voltage in the magnet increases.
9
What causes the compass needles to point in different directions?

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A)Earth’s magnetic field
B)the magnetic field around the magnet
C)the magnetic fields of the compasses
D)the magnetic fields of the Sun and Earth
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