Types of AC Motors: Comprehensive Learning Quizzes

Question 1

To maintain a constant speed of 1800 RPM for an induction motor driving a conveyor belt, which method is most effective?

Accepted Answer

Employ a variable frequency drive (VFD).

Answer

Utilize a mechanical governor.

Answer

Connect a capacitor in parallel with the motor terminals.

Answer

Alter the number of poles in the motor stator.

Question 2

Compared to an induction motor with the same power rating, which characteristics describe a synchronous motor?

Accepted Answer

Higher starting torque and constant speed

Answer

Lower starting torque and variable speed

Answer

Higher starting torque and variable speed

Answer

Lower starting torque and constant speed

Question 3

Which type of AC motor is widely used in industrial applications due to its simplicity, low cost, and high reliability?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 4

What is a key characteristic that distinguishes synchronous motors from other AC motors?

Accepted Answer

Rotor speed is synchronized with the rotating magnetic field

Answer

High starting torque

Answer

Variable speed control

Question 5

Which type of AC motor offers precise angular positioning and is commonly employed in applications like CNC machines and robotic arms?

Accepted Answer

Stepper motor

Answer

Induction motor

Answer

Synchronous motor

Question 6

What is a contrasting feature in the construction of an induction motor compared to a synchronous motor?

Accepted Answer

Induction motor: squirrel cage rotor, synchronous motor: wound rotor

Answer

Induction motor: wound rotor, synchronous motor: squirrel cage rotor

Answer

Both motors have identical rotor construction

Question 7

Which type of AC motor is commonly used in applications requiring adjustable speed control, such as fans and pumps?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 8

What is the primary role of the stator in an AC motor?

Accepted Answer

Generate a rotating magnetic field

Answer

Convert electrical energy into mechanical energy

Answer

Control the speed of the motor

Question 9

Which advantage distinguishes stepper motors from DC motors?

Accepted Answer

Precise angular control

Answer

Higher efficiency

Answer

Lower maintenance

Question 10

What is the function of slip in an induction motor?

Accepted Answer

Enable motor starting under load

Answer

Maintain synchronous speed

Answer

Reduce torque ripple

Question 11

In which application are synchronous motors generally preferred over other AC motor types?

Accepted Answer

Elevators

Answer

Compressors

Answer

Pumps

Question 12

Which type of AC motor features a rotating magnetic field induced in its rotor?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 13

Synchronous motors operate at a consistent speed that is:

Accepted Answer

Equal to the synchronous speed

Answer

Below the synchronous speed

Answer

Above the synchronous speed

Question 14

Stepper motors are frequently employed in applications that demand:

Accepted Answer

Precise positioning control

Answer

High torque generation

Answer

Variable speed adjustment

Question 15

Which of the following is not a type of AC induction motor?

Accepted Answer

DC motor

Answer

Squirrel-cage motor

Answer

Wound-rotor motor

Question 16

Which type of AC motor is most suitable for applications requiring high starting torque?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 17

The slip of an induction motor represents the difference between:

Accepted Answer

Synchronous speed and rotor speed

Answer

Rotor speed and load speed

Answer

Synchronous speed and load speed

Question 18

Stepper motors are often controlled using:

Accepted Answer

Pulse-width modulation technique

Answer

Proportional-integral-derivative control

Answer

Linear feedback control

Question 19

An advantage of synchronous motors over induction motors is:

Accepted Answer

Generally higher efficiency

Answer

Reduced maintenance requirements

Answer

Capability for variable speed operation

Question 20

Typically, the starting current of an AC motor is:

Accepted Answer

Higher than the running current

Answer

Lower than the running current

Answer

Equal to the running current

Question 21

Which type of AC motor relies on the principle of electromagnetic induction for its operation?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 22

What is the defining characteristic of a synchronous motor?

Accepted Answer

It retains a consistent speed irrespective of load variations.

Answer

It enables precise positioning applications.

Answer

It is primarily utilized for high-power applications.

Question 23

Which type of AC motor finds common use in computer disc drives?

Accepted Answer

Stepper motor

Answer

Induction motor

Answer

Synchronous motor

Question 24

What are the benefits offered by stepper motors?

Accepted Answer

Precision in controlling angular position

Answer

High speed and efficiency

Answer

Low cost and durability

Question 25

Which type of winding is used in the stator of an induction motor?

Accepted Answer

Distributed winding

Answer

Lap winding

Answer

Random winding

Question 26

In a synchronous motor, what is the primary purpose of the rotor?

Accepted Answer

It synchronizes the motor's speed with the AC power supply

Answer

It generates the rotating magnetic field

Answer

It transforms electrical energy into mechanical energy

Question 27

Which type of AC motor offers superior efficiency?

Accepted Answer

Synchronous motor

Answer

Induction motor

Answer

Stepper motor

Question 28

What is the key difference between a single-phase and a three-phase induction motor?

Accepted Answer

The number of stator windings

Answer

The speed at which they operate

Answer

The type of power supply required

Question 29

Which AC motor type is often used in applications requiring variable speed?

Accepted Answer

Induction motor with variable frequency drive

Answer

Synchronous motor

Answer

Stepper motor

Question 30

What is the primary role of a capacitor in a single-phase induction motor?

Accepted Answer

To enhance starting torque

Answer

To create a rotating magnetic field

Answer

To reduce motor noise

Question 31

What is the primary distinguishing characteristic of an induction motor?

Accepted Answer

Squirrel-cage rotor and rotating magnetic field

Answer

Permanent magnet on the rotor

Answer

Externally-excited rotor with DC power

Answer

High starting torque and low speed

Question 32

In which industrial application would a synchronous motor be most appropriate?

Accepted Answer

Machine tools requiring precise speed control

Answer

Electric vehicles

Answer

Compressors

Answer

Fans and blowers

Question 33

Which type of AC motor provides precise angular positioning and control suitable for robotics?

Accepted Answer

Stepper motor

Answer

Induction motor

Answer

Synchronous motor

Answer

Brushless DC motor

Question 34

Which of the following is NOT a recognized type of stepper motor?

Accepted Answer

Brushless DC motor

Answer

Permanent magnet stepper motor

Answer

Variable reluctance stepper motor

Answer

Hybrid stepper motor

Question 35

What is the primary factor that determines the speed of a synchronous motor?

Accepted Answer

Frequency of the power supply

Answer

Construction of the rotor

Answer

Load torque applied to the motor

Answer

Configuration of the stator winding

Question 36

In an AC motor, the stator's stationary windings create a rotating magnetic field. How does this field interact with the rotor's windings to generate torque?

Accepted Answer

The rotating magnetic field induces an electric current in the rotor's windings, which then produces torque.

Answer

The rotor's windings create a magnetic field that interacts with the stator's windings to produce torque.

Answer

Both the stator and rotor create magnetic fields, and the interaction between these fields produces torque.

Answer

There is no interaction between the stator and rotor in an AC motor.

Question 37

For the smoothest and most precise stepper motor movement, which control technique is preferred?

Accepted Answer

Microstepping control

Answer

Full-step control

Answer

Half-step control

Question 38

For starting loads with high inertia, which type of induction motor is most appropriate?

Accepted Answer

Slip ring induction motor

Answer

Squirrel cage induction motor

Answer

Synchronous motor

Question 39

Identify the type of AC motor whose rotating magnetic field induces currents in its rotor, leading to torque generation.

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 40

Distinguish stepper motors from other AC motors based on their primary characteristic.

Accepted Answer

Precise angular control

Answer

High initial torque

Answer

Continuous rotational motion

Question 41

Indicate the type of AC motor that is commonly employed in applications where variable speed control is essential, such as electric vehicles.

Accepted Answer

Synchronous motor with variable frequency drive

Answer

Induction motor

Answer

Stepper motor

Question 42

Identify the primary function of the squirrel cage rotor found in induction motors.

Accepted Answer

Carrying induced currents

Answer

Generating a rotating magnetic field

Answer

Providing structural support

Question 43

Specify a common application where stepper motors are frequently employed.

Accepted Answer

Industrial automation systems

Answer

Electrical power generation facilities

Answer

Automotive electronic systems

Question 44

Which type of AC motor relies on electromagnetic induction to generate torque?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 45

Select the AC motor type that maintains a constant rotational speed, regardless of load variations.

Accepted Answer

Synchronous motor

Answer

Induction motor

Answer

Stepper motor

Question 46

Which application is most suitable for the use of a stepper motor?

Accepted Answer

Positioning equipment

Answer

Driving industrial machinery

Answer

Powering pumps

Question 47

In an induction motor, the rotor conductors experience:

Accepted Answer

Alternating current (AC)

Answer

Direct current (DC)

Answer

Permanent magnet field

Question 48

Which type of AC motor is commonly used in industrial settings due to its high torque capability?

Accepted Answer

Induction motor

Answer

Synchronous motor

Answer

Stepper motor

Question 49

Identify the component in a stepper motor that controls the number of steps per revolution.

Accepted Answer

Controller

Answer

Rotor

Answer

Stator

Question 50

Which motor type is typically used in applications requiring precise positioning, such as robotic arms?

Accepted Answer

Stepper motor

Answer

Induction motor

Answer

Synchronous motor