Deck 19: Single-Phase Motors

Question 1

The current relay contains a coil with a few turns of large wire and a set of normally closed contacts.

Answer 1

False

Question 2

A two-phase system is produced by having an alternator with two sets of coils wound ____ degrees apart.

A) 60
B) 90
C) 120
D) 150

Answer 2

B

Question 3

Split-phase motors split the current flow through ____ separate windings.

A) two
B) three
C) four
D) five

Answer 3

A

Question 4

The capacitor-start capacitor-run motor ____.

A) operates on the same principle as the resistance-start induction-run motor
B) is not a split-phase motor
C) is designed so that its start winding remains energized at all times
D) operates on the same principle as the capacitor-start induction-run motor

Question 5

The ____ motor is constructed with a laminated stator core and a single coil. The coil is generally wound for 120-V AC operation. The rotor is constructed by stacking hardened steel laminations onto the rotor shaft.

A) Holtz
B) Warren
C) universal
D) asynchronous

Question 6

The stator of a split-phase motor contains two separate windings, the start winding and the ____ winding.

A) go
B) split
C) run
D) stop

Question 7

All dual-voltage single-phase motors contain two sets of start windings.

Question 8

The rotating magnetic field in a shaded-pole induction motor is created by a ____ coil wound on one side of each pole piece.

A) transformer
B) short
C) static
D) shading

Question 9

Single-phase synchronous motors require DC excitation current.

Question 10

The ____ motor has a rotor that is cut in such a manner that six slots are formed. These slots form six salient (projecting or jutting) poles for the rotor.

A) Holtz
B) Warren
C) universal
D) asynchronous

Question 11

The direction of motor rotation ____.

A) is independent of the direction of rotation of the magnetic field created when the motor is first started
B) can be changed by reversing the direction of either winding, but not both
C) can be changed by reversing the direction of both windings
D) cannot be changed

Question 12

When the current of the AC waveform increases from zero toward its positive peak, a magnetic field is created in the pole piece.

Question 13

Motors that are not hermetically sealed use a(n) ____ switch to disconnect the start windings from the circuit.

A) accelerator
B) stator
C) split-phase
D) centrifugal

Question 14

Capacitor-start capacitor-run motors that are not hermetically sealed contain a centrifugal switch to disconnect the start capacitor when the motor reaches about ____% of its full load speed.

A) 25
B) 50
C) 75
D) 90

Question 15

The universal motor is often referred to as a(n) ____ motor.

A) AC parallel
B) AC series
C) DC parallel
D) DC series

Question 16

Although the capacitor-start induction-run motor has a high starting torque, the motor should not be started more than about ____ times per hour.

A) two
B) four
C) six
D) eight

Question 17

There are ____ basic types of multispeed single-phase motors.

A) two
B) three
C) four
D) five

Question 18

Universal motors ____.

A) are used in a number of portable appliances
B) have very good speed regulation
C) are always operated under 1,000 RPM
D) do not produce a high horsepower

Question 19

One of the two basic types of starting relays used with the resistance start and capacitor start motors is the ____ relay.

A) voltage
B) hot-wire
C) resistance
D) rotor

Question 20

A rotating magnetic field can be produced with only one phase.