Question 1

Single-phase motors require ____ windings to operate.
A)main
B)auxiliary
C)terminal
D)three-phase

Accepted Answer

Single-phase motors require an auxiliary winding to generate a starting torque and to provide a phase shift in the current to create a rotating magnetic field.

Question 2

____________________ capacitors are usually large microfarad AC electrolytic, and are designed to be in the energized circuit for only a short period of time.

Accepted Answer

Start

Question 3

The ____________________ switch assembly of the single-phase induction motor is designed to open the auxiliary start winding circuit once the rotor has reached a pre-determined speed.

Accepted Answer

centrifugal

Question 4

The standard direction of rotation for single-phase motors is counter-clockwise from the front of the motor, the end opposite the drive.

Accepted Answer

The standard direction of rotation for single-phase motors is indeed counter-clockwise from the front of the motor, the end opposite the drive.

Question 5

What are at least two disadvantages to using single-phase motors?

Accepted Answer

The answer of What are at least two disadvantages to...

Question 6

All motor applications require ____________________-phase motors in residential buildings.

Accepted Answer

The answer of All motor applications require ____________________-phase motors in...

Question 7

As the rotor reaches approximately ____% of synchronous speed, the auxiliary start winding is no longer necessary.
A)25
B)50
C)75
D)95

Accepted Answer

According to the question, as the rotor reaches approximately 75% of synchronous speed, the auxiliary start winding is no longer necessary. Therefore, the correct choice is C.

Question 8

The difference in ____ values causes the current in the auxiliary start winding to slightly lead the current in the run winding.
A)conductance
B)conductor
C)magnetic
D)inductance

Accepted Answer

The difference in inductance values causes the current in the auxiliary start winding to slightly lead the current in the run winding.

Question 9

Single-phase induction motors are less complicated than three-phase motors.

Accepted Answer

The answer of Single-phase induction motors are less complicated than...

Question 10

The ____ voltage found on motors is a terminal voltage, meaning that this is the voltage that should exist at the motor terminals after experiencing the feeder and branch circuit voltage drops of the electrical system.
A)NEMA
B)IEC
C)nameplate
D)de-energized

Accepted Answer

The voltage found on the motor nameplate is the rated voltage for the motor, and this is the voltage that should exist at the motor terminals after accounting for voltage drops in the electrical system. The other choices (NEMA, IEC, de-energized) do not refer specifically to the voltage found on motors.

Question 11

The main winding is also called the ____ winding.
A)run
B)terminal
C)auxiliary
D)stop

Accepted Answer

The main winding is also known as the run winding because it is responsible for producing the rotational force that drives the motor's operation.

Question 12

Single-phase induction motors are typically fractional horsepower; less than 1 HP.

Accepted Answer

Single-phase induction motors are typically used for small applications such as fans, pumps, and other applications requiring less than 1 horsepower.

Question 13

____ capacitors do not depend on a chemical reaction to achieve their capacitance, so they can be across the AC power supply line indefinitely.
A)Run
B)Start
C)Split-phase
D)Terminal

Accepted Answer

Run capacitors are designed to stay connected to the power supply indefinitely and do not depend on chemical reactions to achieve their capacitance. This makes them suitable for use across AC power supply lines. Start capacitors, on the other hand, are designed to provide an initial boost to motor starting and are not intended for continuous operation. Split-phase and terminal capacitors are specific types of capacitors used in certain motor applications and are not general-purpose capacitors like run and start capacitors.

Question 14

____________________ capacitors are usually small microfarad paper and foil type, and are designed to be in the energized circuit for extended periods of time.

Accepted Answer

The answer of ____________________ capacitors are usually small microfarad paper...

Question 15

The ____ motor has no centrifugal switch assembly, auxiliary start winding contact, or start capacitor.
A)capacitor-start
B)capacitor-run
C)capacitor-start, capacitor-run
D)split-phase

Accepted Answer

The capacitor-run motor does not have a centrifugal switch assembly, auxiliary start winding contact, or start capacitor.

Question 16

The ____ motor is suitable only for loads with low locked rotor torque, such as fans and circulation pumps.
A)capacitor-start
B)capacitor-run
C)capacitor-start, capacitor-run
D)split-phase

Accepted Answer

Split-phase motors are suitable for low locked rotor torque applications like fans and circulation pumps, as they have moderate starting torque but do not maintain high torque throughout their operation.

Question 17

Large commercial and industrial building applications most often will use ____________________-phase motors.

Accepted Answer

The answer of Large commercial and industrial building applications most...

Question 18

The ____ of rotation for single-phase motors is determined by the minute time differences between when the main run winding and the auxiliary start winding build a strong magnetic pole field, and the magnetic pole polarity differences between them.
A)direction
B)magnetism
C)strength
D)torque

Accepted Answer

The direction of rotation for single-phase motors is determined by the minute time differences between when the main run winding and the auxiliary start winding build a strong magnetic pole field, and the magnetic pole polarity differences between them. The other options - magnetism, strength, and torque - are not directly related to determining the direction of rotation in single-phase motors.

Question 19

The operating characteristics of ____ motors make them suitable for applications like conveyors and compressors because of their high locked-rotor starting torque to get a load moving.
A)capacitor-start
B)capacitor-run
C)capacitor-start, capacitor-run
D)split-phase

Accepted Answer

Capacitor-start motors are known for their high locked-rotor starting torque, making them suitable for applications like conveyors and compressors that require significant torque to start moving.

Question 20

The ____ motor has a start capacitor in series with the auxiliary winding like the capacitor-start motor for improved high locked-rotor starting torque.
A)capacitor-start
B)capacitor-run
C)capacitor-start, capacitor run
D)split-phase

Accepted Answer

The description matches that of a capacitor-start, capacitor-run motor, which has both a start capacitor and a run capacitor in the circuit. This configuration provides improved high locked-rotor starting torque compared to a basic capacitor-start motor.

Quiz 4: Single-Phase Induction Motors

Single-phase motors require ____ windings to operate.

____________________ capacitors are usually large microfarad AC electrolytic, and are designed to be in the energized circuit for only a short period of time.

The ____________________ switch assembly of the single-phase induction motor is designed to open the auxiliary start winding circuit once the rotor has reached a pre-determined speed.

The standard direction of rotation for single-phase motors is counter-clockwise from the front of the motor, the end opposite the drive.

What are at least two disadvantages to using single-phase motors?

All motor applications require ____________________-phase motors in residential buildings.

As the rotor reaches approximately ____% of synchronous speed, the auxiliary start winding is no longer necessary.

The difference in ____ values causes the current in the auxiliary start winding to slightly lead the current in the run winding.

Single-phase induction motors are less complicated than three-phase motors.

The ____ voltage found on motors is a terminal voltage, meaning that this is the voltage that should exist at the motor terminals after experiencing the feeder and branch circuit voltage drops of the electrical system.

The main winding is also called the ____ winding.

Single-phase induction motors are typically fractional horsepower; less than 1 HP.

____ capacitors do not depend on a chemical reaction to achieve their capacitance, so they can be across the AC power supply line indefinitely.

____________________ capacitors are usually small microfarad paper and foil type, and are designed to be in the energized circuit for extended periods of time.

The ____ motor has no centrifugal switch assembly, auxiliary start winding contact, or start capacitor.

The ____ motor is suitable only for loads with low locked rotor torque, such as fans and circulation pumps.

Large commercial and industrial building applications most often will use ____________________-phase motors.

The ____ of rotation for single-phase motors is determined by the minute time differences between when the main run winding and the auxiliary start winding build a strong magnetic pole field, and the magnetic pole polarity differences between them.

The operating characteristics of ____ motors make them suitable for applications like conveyors and compressors because of their high locked-rotor starting torque to get a load moving.

The ____ motor has a start capacitor in series with the auxiliary winding like the capacitor-start motor for improved high locked-rotor starting torque.