Deck 9: Basic Electric Motors

Question 1

An alternating current of 60 hertz changes direction 100 times per second.

Answer 1

False

Question 2

To make an electric motor move continuously, the magnetic field must rotate.

Answer 2

True

Question 3

If the north pole of a bar magnet is brought close to the north pole of another bar magnet, they will ____________________ each other.

Answer 3

repel

Question 4

If the south pole of a bar magnet is brought close to the north pole of another bar magnet, they will ____________________ each other.

Question 5

Magnetism can only be produced by the earth's core.

Question 6

The resistance-start-induction-run motor has only a starting winding.

Question 7

The capacitor consists of two aluminum plates with an insulator between them.

Question 8

What is induced magnetism? When is the magnetic field stronger?

Question 9

All magnets have three poles.

Question 10

The magnetic lines of force of a magnet that flow between the north and south poles are called ____________________.

Question 11

The most commonly used rotor today is the ____________________ rotor.

Question 12

Motors are selected mainly because of the starting torque required for the motor to perform its function.

Question 13

A permanent magnet is a piece of magnetic material that has been magnetized and can hold its magnetic strength for a reasonable length of time.

Question 14

The ____________________ is a brushless DC, three-phase motor with a permanent magnet rotor.

Question 15

Motor speed is generally used to classify motors into different types.

Question 16

Two types magnets are in use today: the electromagnet and the ____________________ magnet.

Question 17

What is magnetism?

Question 18

The electromagnet is a magnet produced through ____________________.

Question 19

An alternating current motor's speed is determined by the frequency of the power supply only.

Question 20

How do electric motors work?