Deck 19: Single-Phase Motors

Question 1

A centrifugal switch disconnects the start winding from the motor circuit when the motor reaches ____% of its rated speed.

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

Answer 1

C

Question 2

A ____ operates on the principle of a magnetic field instead of expanding metal.

A) current relay
B) hot-wire relay
C) solid state relay

Answer 2

A

Question 3

Because it is intended for continuous use, the capacitor of a capacitor-start capacitor-run motor is generally a(n) ____ type.

A) electrolytic
B) oil-filled
C) distribution
D) reactive

Answer 3

B

Question 4

The capacitor-start capacitor-run motor is designed so that the ____ while the motor is energized.

A) start winding is disconnected and the run winding remains connected
B) run winding is disconnected and the start winding remains connected
C) both the run winding and the start winding remain connected

Question 5

Because the Holtz motor has a rotor cut with six slots, the motor speed produced is ____ RPM.

A) 3600
B) 1800
C) 1200
D) 900

Question 6

When determining the direction of rotation of a motor, you should be looking at the ____ of the motor.

A) left side
B) right side
C) front
D) rear

Question 7

A motor with 8 stator poles will have a rated speed of approximately ____ RPM.

A) 3600
B) 1800
C) 1200
D) 900

Question 8

A motor that has 4 stator poles will have a rated speed of approximately ____ RPM.

A) 3600
B) 1800
C) 1200
D) 900

Question 9

The capacitor-start induction-run motor produces a starting torque that is ____ that of the resistance-start induction-run motor.

A) higher than
B) lower than
C) about the same as

Question 10

Since both the start winding and the run winding of a capacitor-start capacitor-run motor remain energized at all times, the motor operates as a ____-phase motor.

A) one
B) two
C) three

Question 11

To reverse the direction of a shaded-pole motor, you need to ____.

A) reverse the leads of the start or the run winding
B) reverse the leads of both the start and run windings
C) remove the stator winding and turn it around

Question 12

When connecting a dual voltage motor for high voltage, the leads must be connected in ____.

A) parallel
B) series
C) series-parallel

Question 13

Because the start winding is wound with smaller wire and placed near the top of the stator, it will have ____ the run winding.

A) higher resistance than
B) lower resistance than
C) the same resistance as

Question 14

A thermistor is a device that exhibits a change of resistance with a change of ____.

A) voltage
B) amperage
C) power
D) temperature

Question 15

The ____ functions as both a starting relay and an overload relay.

A) current relay
B) hot-wire relay
C) solid state starting relay

Question 16

Capacitors are rated in ____.

A) volts
B) farads
C) amperage
D) watts

Question 17

When the leads of the compensating winding of a universal motor are shorted together, the connection is known as ____ compensation.

A) conductive
B) inductive
C) reactive
D) capacitance

Question 18

When a universal motor is operated on AC and the compensating winding is connected in series with the armature, it is known as ____ compensation.

A) conductive
B) reactive
C) inductive
D) capacitance

Question 19

The direction of rotation of a single-phase motor can be changed by reversing the connection of the ____.

A) start winding
B) run winding
C) either the start winding or the run winding
D) both the start winding and the run winding.

Question 20

In motors, the speed of the magnetic rotating field is called the ____ speed.

A) rotating
B) power
C) split-phase
D) synchronous

Question 21

When a single-phase motor has only one start winding, the leads are generally numbered ____________________ and ____________________.

Question 22

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

Question 23

The two basic types of multispeed single-phase motors are a specially wound capacitor-start capacitor-run motor and the ____________________ pole motor.

Question 24

The ____________________ relay performs the same function as the current relay and is now being used to replace the current relay and the centrifugal switch.

Question 25

Because motors that are hermetically sealed cannot use centrifugal switches to disconnect the start winding from the circuit, _________________________ are used to perform this function.

Question 26

Split-phase motors split the current through separate windings to simulate a ____________________-phase power system.

Question 27

The ____________________ motor is often referred to as an AC series motor and has a wound armature and brushes.

Question 28

When connecting a dual voltage motor for high voltage, the leads are connected in ____________________.

Question 29

Frequent starting can damage a start capacitor due to ____________________.

Question 30

When reversing the direction of rotation for an universal motor, the armature leads must be changed with respect to the ____________________ leads.

Question 31

Motors that are not hermetically sealed use a(n) ______________________________ to disconnect the start winding from the circuit.

Question 32

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

Question 33

In a shaded-pole induction motor, the rotating magnetic field is created by a(n) ____________________ coil wound on one side of each pole piece.

Question 34

Because the rotor of the Warren motor has two crossbars, its speed is rated at ____________________ RPM.

Question 35

A solid state starting relay is actually an electronic device known as a ____________________.

Question 36

The ____________________ motor can operate on either AC or DC.

Question 37

When a universal motor has the leads of its compensating winding shorted together, it must be operated on ____.

A) AC
B) DC
C) either AC or DC

Question 38

If a capacitor with too little capacitance or a capacitor with too much capacitance is used to start a motor, the starting torque of the motor will be ____________________.

Question 39

A capacitor-start induction-run motor has an electrolytic capacitor connected in series with the centrifugal switch and the _________________________.

Question 40

The ____________________ of a shaded-pole motor is determined by frequency and the number of stator poles.