Introduction To Physical Science

Chapter 21: Magnetism

Magnetism

1
Which of the following devices produces electric current?
A)motor
B)compass
C)generator
D)electric fan
2
What effect does increasing the current flowing in the wire have on an electromagnet?
A)It causes it to become a permanent magnet.
B)It has no effect on the electromagnet.
C)It increases the strength of the magnetic field.
D)It decreases the strength of the magnetic field.
3
The magnetic field that surrounds Earth is called the __________.
A)magnetron
B)magnetic domain
C)magnetic polar region
D)magnetosphere
4
Magnetic fields that surround all magnets exert __________.
A)air pressure
B)the magnetic force
C)resistance
D)electric current
5
The __________ are regions where the magnetic force exerted by a magnet is strongest.
A)magnetic poles
B)cathodes
C)anodes
D)magnetic field lines
6
The negatively charged particles in an atom are called __________.
A)electrons
B)neutrons
C)protons
D)negatrons
7
Groups of atoms with aligned magnetic poles are called __________.
A)magnetic domains
B)permanent magnets
C)elements
D)magnetic fields
8
Which of the following statements about Earth's magnetic field is true?
A)Earth's magnetic field extends about 10 m above Earth's surface.
B)When molten rock cools, the iron in it no longer contains magnetic domains.
C)It is possible for Earth's magnetic field to reverse.
D)A magnetic pole is permanent but a geographic pole is not.
9
The input coil of a step-up transformer has 10 turns and its output coil has 100 turns. What is the voltage in the output coil if the input voltage is 50 V?
A)4500 V
B)500 V
C)5500 V
D)160 V
10
Magnetic field lines that curve away from each other show __________.
A)repulsion
B)where the magnetic field is strongest
C)a magnetic domain
D)attraction
11
A(n) __________ is a magnetic needle that is free to move and that itself along magnetic field lines.
A)domain
B)electromagnet
C)pole
D)compass
12
What is responsible for generating Earth's magnetic field?
A)solar wind streaming toward Earth
B)movement of iron in the core
C)the Moon's strong gravitational pull on Earth
D)Earth's revolution
13
Which of the following is found in all magnets?
A)a geographic pole
B)a north pole and a south pole
C)an electrical field
D)a transformer
14
Magnetic fields are created by __________.
A)magnetic field lines
B)moving electric charges
C)potential energy of molecules
D)spinning neutrons
15
The interaction between two magnets is called __________.
A)polarity
B)current
C)magnetic force
D)a magnetic field
16
Electric current should pass through a __________ after being transmitted by a power plant and before it enters your home.
A)step-down transformer
B)turbine
C)generator
D)step-up transformer
17
Which of the following devices can increase or decrease the voltage of an alternating current?
A)transformer
B)battery
C)generator
D)motor
18
Which of the following changes electrical energy into kinetic energy?
A)electric motor
B)transformer
C)superconductor
D)generator
19
How do homing pigeons use Earth's magnetic field to find their way?
A)They utilize GPS technology.
B)They pick up bits of magnetic material on their wings.
C)They have natural magnets in their brains.
D)They have natural magnets on their feet.
20
__________ flows in only one direction through a wire.
A)Direct current
B)Voltage
C)Alternating current
D)Electric current
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