Physical Science, New York Edition

Chapter 8: Magnetism and Its Uses

Magnetism and Its Uses

1.
Which of the following devices can increase or decrease the voltage of an alternating current?
A)battery
B)generator
C)galvanometer
D)transformer
2.
Alternating current changes the __________ of the current flow.
A)amount
B)direction
C)strength
D)voltage
3.
In order for the electromagnetic coil in a motor to keep turning, the current must __________ .
A)flow through an ammeter
B)change direction
C)periodically increase in strength
D)continue flowing in one direction
4.
Electric current should pass through a __________ after being transmitted by a power plant and before it enters your home.
A)generator
B)step-up transformer
C)turbine
D)step-down transformer
5.
The __________ are regions where the magnetic force exerted by a magnet is strongest.
A)cathodes
B)anodes
C)magnetic poles
D)magnetic field lines
6.
The interaction between two magnets is called __________ .
A)a magnetic field
B)polarity
C)current
D)magnetic force
7.
Which of the following best describes how electricity is generated for homes?
A)The spinning of a windmill's blades creates electric current without a generator.
B)Steam pushes turbine blades in a generator, which changes the mechanical energy into an electric current.
C)Water released from a dam generates electric current, which is transformed into mechanical energy.
D)Nuclear reactions cause electric current to flow around the reaction chamber.
8.
Which of the following devices produces electric current?
A)stereo speaker
B)electric motor
C)galvanometer
D)generator
9.
North poles of magnets always attract __________ .
A)other north poles
B)negative charges
C)south poles
D)positive charges
10.
Which of the following elements is magnetic?
A)aluminum
B)lead
C)iron
D)tin
11.
The magnetic field that surrounds a magnet exerts __________ .
A)resistance
B)electrical current
C)the magnetic force
D)air pressure
12.
Groups of atoms with aligned magnetic poles are called __________ .
A)magnetic fields
B)magnetic domains
C)elements
D)permanent magnets
13.
Which of the following best describes an electromagnet?
A)insensitive to electrical currents
B)permanent magnet
C)temporary magnet
D)unchanging magnetic properties
14.
Why does the north pole of a compass point toward Earth's geographic north pole?
A)A compass does not rely on Earth's magnetic field to function.
B)Like poles attract.
C)Opposite poles repel.
D)Earth's geographic north pole is a south magnetic pole.
15.
What effect does increasing the current flowing in the wire have on an electromagnet?
A)It increases the strength of the magnetic field.
B)It causes it to become a permanent magnet.
C)It has no effect on the electromagnet.
D)It decreases the strength of the magnetic field.
16.
Which of the following is found in all magnets?
A)a geographic pole
B)a transformer
C)an electrical field
D)a north pole and a south pole
17.
Iron is a magnetic material, but an iron nail does not behave like a magnet because __________ .
A)its magnetic domains are arranged randomly
B)the atoms in the iron exert a force on all the other atoms
C)it contains too few magnetic domains
D)its magnetic domains are aligned
18.
When a bar magnet is broken into two pieces, each piece has a north and south pole because __________.
A)the magnetic fields reversed
B)every magnet is made of many aligned smaller magnets
C)bar magnets are permanent magnets
D)the magnetic poles have been isolated
19.
Which of the following is a form of electromagnetic induction?
A)changing electrical energy to mechanical energy that produces sound
B)producing mechanical energy by sending electric current through an electromagnet
C)using an electromagnet to measure electric current
D)producing electric current by moving a magnet through a wire loop
20.
Why do power plants commonly produce alternating current?
A)It is more economical to produce.
B)It does not lose energy as heat when transmitted over long distances.
C)Voltage of alternating current can be increased or decreased with transformers.
D)Less resistance is created in the wire.
Physical Science - New York Edition
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