Applications of Electromagnetic Induction Answers

14 verified answers
1
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What parts are found in an electric generator? Select 4 options.

A
an armature
B
a battery
C
a permanent magnet
D
an electromagnet
E
brushes
F
slip rings
3

In a step-down transformer, which describes the primary winding compared with the secondary winding?

A
higher voltage and fewer coils of wire
B
higher voltage and more coils of wire
C
lower voltage and fewer coils of wire
D
lower voltage and more coils of wire
4

How does an electric generator work?

A
The axle rotates the armature in the magnetic field of a permanent magnet, which induces an electric current.
B
The armature rotates the axle in the magnetic field of a permanent magnet, which induces an electric current.
C
The axle rotates the armature in the magnetic field of an electromagnet, which induces an electric current.
D
The armature rotates the axle in the magnetic field of an electromagnet, which induces an electric current.
6

Which best describes the steps involved in the operation of an electric generator?

A
The electric current passes from the power source, through the brushes, and into the commutator.
B
The electric current passes from the brushes, through the slip rings, and to the collection device.
C
The electric current passes from the slip rings, through the brushes, and to the collection device.
D
The electric current passes from the commutator, through the brushes, and into the power source.
8

Which is an important step in how an electric motor uses magnetic force to produce motion?

A
As the north pole of the electromagnet nears the north pole of the permanent magnet, the current reverses and the poles of the magnets then attract.
B
As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
C
As the north pole of the electromagnet nears the north pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
D
As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then attract.
9

Elena makes a table to organize the functions of electric motor components.Which functions belong in the cells marked X and Y?

Question illustration
A
X: Conducts current to the armature and reverses direction of currentY: Rotates as a result of changing magnetic forces
B
X: Rotates as a result of changing magnetic forcesY: Conducts current to the armature and reverses direction of current
C
X: Allows current to flow into the commutatorY: Conducts current to the armature and reverses direction of current
D
X: Allows current to flow into the commutatorY: Rotates as a result of changing magnetic forces
11

How does an electric motor use magnetic force to produce motion?

A
The north pole of a permanent magnet placed in the center of an electromagnet attracts the north pole of the electromagnet.
B
The north pole of an electromagnet placed in the center of a permanent magnet attracts the north pole of the permanent magnet.
C
The north pole of a permanent magnet placed in the center of an electromagnet repels the north pole of the electromagnet.
D
The north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet.
13

Keiko builds a transformer in the lab, but it does not decrease the voltage as much as she needs. What should Keiko change to further reduce the voltage?

A
She should make the number of coils in the primary winding less than in the secondary winding.
B
She should make the number of coils in the primary winding the same as in the secondary winding.
C
She should increase the number of coils in the secondary winding.
D
She should increase the number of coils in the primary winding.
14

Which device converts electrical energy into kinetic energy?

A
an electric generator
B
an electric motor
C
a step-down transformer
D
a step-up transformer

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