Question 1

What factors play a role in the performance of dc motors?

Accepted Answer

The performance of a dc motor depends up...

Question 2

Most dual-voltage single-phase motors will be of the ____ type, which contains both run and starting windings.

Accepted Answer

A)   monophase
B)   split-phase
C)   biphase
D)   schematicE) None of the above
F) A) and D)

Question 3

In a machine that has a 3-phase motor rated at 460 volts, the current required by each machine is based on the ____ of the motor.

Accepted Answer

A)   efficiency
B)   volts
C)   power factor
D)   horsepower ratingE) B) and C)
F) A) and D)

Question 4

What is the significance of the IGBT?

Accepted Answer

Many transistor-controlled variable driv...

Question 5

The ____ operates like an electric check valve; it permits the current to flow through it in only one direction.

Accepted Answer

A)   inductor
B)   diode
C)   resistor
D)   capacitorE) A) and D)
F) A) and C)

Question 6

How do primary resistance starters work?

Accepted Answer

The milling machines are equipped with p...

Question 7

The force acting at the rim of the rotor multiplied by the radius from the center of the rotor is called the ____.

Accepted Answer

A)   horsepower
B)   torque
C)   rotor speed
D)   angular momentumE) A) and B)
F) A) and C)

Question 8

A(n)  ____ uses two SCRs and two diodes.

Accepted Answer

A)   integrated circuit
B)   transistor
C)   bridge rectifier
D)   inductorE) B) and C)
F) A) and B)

Question 9

Three-phase motors can be constructed to operate in either wye or ____.

Accepted Answer

A)   delta
B)   star
C)   Kennelly
D)   cycleE) None of the above
F) A) and C)

Question 10

An induction motor is much like a(n)  ____, except that the secondary winding and core are mounted on a shaft set in bearings.

Accepted Answer

A)   limit switch
B)   ohmmeter
C)   transformer
D)   voltmeterE) All of the above
F) A) and C) C

Question 11

SCRs and GTOs are ____ and have the ability to handle a greater amount of current than transistors.

Accepted Answer

A)   thyristors
B)   integrated circuits
C)   resistors
D)   capacitorsE) B) and C)
F) A) and D)

Question 12

Direct-current compound motors contain a rotating armature and a(n)  ____ field.

Accepted Answer

A)   stationary
B)   interpole
C)   commutator
D)   brushE) C) and D)
F) A) and D)

Question 13

The speed of the wound-rotor induction motor can be controlled by the amount of ____ connected in the rotor circuit.

Accepted Answer

A)   capacitance
B)   voltage
C)   resistance
D)   inductanceE) A) and D)
F) B) and D)

Question 14

Describe how rotation results in the squirrel-type induction motor.

Accepted Answer

The squirrel-cage type of induction moto...

Question 15

The torque reaches maximum when the rotor and stator currents are ____ with each other.

Accepted Answer

A)   in phase
B)   60 degrees out of phase
C)   120 degrees out of phase
D)   150 degrees out of phaseE) B) and C)
F) A) and D) A

Question 16

Most dual-voltage motors bring out ____ "T" leads at the terminal box.

Accepted Answer

A)   three
B)   six
C)   nine
D)   tenE) A) and C)
F) B) and D)

Question 17

The speed of the rotating magnetic field of a polyphase ac motor is called ____ speed.

Accepted Answer

A)   variable
B)   critical
C)   synchronous
D)   proportionalE) B) and C)
F) A) and D)

Question 18

A six-pole motor has a coil span of ____.

Accepted Answer

A)   60
B)   90
C)   120
D)   180E) None of the above
F) A) and B)

Question 19

Although the ____ compound motor gives a more constant speed at all loads, the motor is somewhat unstable.

Accepted Answer

A)   armature
B)   shunt
C)   cumulative
D)   differentialE) All of the above
F) B) and D)

Question 20

What is the role of interpoles in dc motors?

Accepted Answer

Commutating poles or interpoles are very small pole pieces that are placed midway between the main pole pieces. The interpoles are wound with a few turns of heavy wire. As with the main pole pieces, the interpoles are also wound in an alternate clockwise and counterclockwise manner. The pole pieces are connected permanently in series with the armature brush holders and are considered to be a part of the armature circuit. Interpoles counteract the distortion of the field magnetism caused by the rotation of the heavily magnetized armature in the field flux. As a result, sparking or arcing at the brushes is reduced.

Exam 9: Motors and Controllers

What factors play a role in the performance of dc motors?

Correct Answer
verified
The performance of a dc motor depends up...
View Answer

Most dual-voltage single-phase motors will be of the ____ type, which contains both run and starting windings.

Correct Answer
verified

In a machine that has a 3-phase motor rated at 460 volts, the current required by each machine is based on the ____ of the motor.

Correct Answer
verified

What is the significance of the IGBT?

Correct Answer
verified
Many transistor-controlled variable driv...
View Answer

The ____ operates like an electric check valve; it permits the current to flow through it in only one direction.

Correct Answer
verified

How do primary resistance starters work?

Correct Answer
verified
The milling machines are equipped with p...
View Answer

The force acting at the rim of the rotor multiplied by the radius from the center of the rotor is called the ____.

Correct Answer
verified

A(n) ____ uses two SCRs and two diodes.

Correct Answer
verified

Three-phase motors can be constructed to operate in either wye or ____.

Correct Answer
verified

An induction motor is much like a(n) ____, except that the secondary winding and core are mounted on a shaft set in bearings.

Correct Answer
verified
C

SCRs and GTOs are ____ and have the ability to handle a greater amount of current than transistors.

Correct Answer
verified

Direct-current compound motors contain a rotating armature and a(n) ____ field.

Correct Answer
verified

The speed of the wound-rotor induction motor can be controlled by the amount of ____ connected in the rotor circuit.

Correct Answer
verified

Describe how rotation results in the squirrel-type induction motor.

Correct Answer
verified
The squirrel-cage type of induction moto...
View Answer

The torque reaches maximum when the rotor and stator currents are ____ with each other.

Correct Answer
verified
A

Most dual-voltage motors bring out ____ "T" leads at the terminal box.

Correct Answer
verified

The speed of the rotating magnetic field of a polyphase ac motor is called ____ speed.

Correct Answer
verified

A six-pole motor has a coil span of ____.

Correct Answer
verified

Although the ____ compound motor gives a more constant speed at all loads, the motor is somewhat unstable.

Correct Answer
verified

What is the role of interpoles in dc motors?

Exam 9: Motors and Controllers

What factors play a role in the performance of dc motors?

Correct AnswerverifiedThe performance of a dc motor depends up...View AnswerShow Answer

Most dual-voltage single-phase motors will be of the ____ type, which contains both run and starting windings.

Correct AnswerverifiedShow Answer

In a machine that has a 3-phase motor rated at 460 volts, the current required by each machine is based on the ____ of the motor.

Correct AnswerverifiedShow Answer

What is the significance of the IGBT?

Correct AnswerverifiedMany transistor-controlled variable driv...View AnswerShow Answer

The ____ operates like an electric check valve; it permits the current to flow through it in only one direction.

Correct AnswerverifiedShow Answer

How do primary resistance starters work?

Correct AnswerverifiedThe milling machines are equipped with p...View AnswerShow Answer

The force acting at the rim of the rotor multiplied by the radius from the center of the rotor is called the ____.

Correct AnswerverifiedShow Answer

A(n) ____ uses two SCRs and two diodes.

Correct AnswerverifiedShow Answer

Three-phase motors can be constructed to operate in either wye or ____.

Correct AnswerverifiedShow Answer

An induction motor is much like a(n) ____, except that the secondary winding and core are mounted on a shaft set in bearings.

Correct AnswerverifiedC

SCRs and GTOs are ____ and have the ability to handle a greater amount of current than transistors.

Correct AnswerverifiedShow Answer

Direct-current compound motors contain a rotating armature and a(n) ____ field.

Correct AnswerverifiedShow Answer

The speed of the wound-rotor induction motor can be controlled by the amount of ____ connected in the rotor circuit.

Correct AnswerverifiedShow Answer

Describe how rotation results in the squirrel-type induction motor.

Correct AnswerverifiedThe squirrel-cage type of induction moto...View AnswerShow Answer

The torque reaches maximum when the rotor and stator currents are ____ with each other.

Correct AnswerverifiedA

Most dual-voltage motors bring out ____ "T" leads at the terminal box.

Correct AnswerverifiedShow Answer

The speed of the rotating magnetic field of a polyphase ac motor is called ____ speed.

Correct AnswerverifiedShow Answer

A six-pole motor has a coil span of ____.

Correct AnswerverifiedShow Answer

Although the ____ compound motor gives a more constant speed at all loads, the motor is somewhat unstable.

Correct AnswerverifiedShow Answer

What is the role of interpoles in dc motors?

Correct Answer
verified
The performance of a dc motor depends up...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Many transistor-controlled variable driv...
View Answer

Correct Answer
verified

Correct Answer
verified
The milling machines are equipped with p...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The squirrel-cage type of induction moto...
View Answer

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified