Electrical Machines (Part-11)

What is the role of the stator in an electrical machine?

A Supply power
B Produce magnetic field
C Generate torque
D Control speed

What is the primary function of the rotor in an induction motor?

A To regulate voltage
B To control speed
C To generate a magnetic field
D To produce mechanical output

In a synchronous machine, where are the field windings typically located?

A Armature
B Shaft
C Rotor
D Stator

What happens if the rotor in a synchronous motor is not synchronized with the stator?

A Motor stalls
B Motor increases efficiency
C Motor accelerates
D Motor speeds up

How does the stator winding in a synchronous motor affect the motor’s performance?

A Supplies current
B Controls speed
C Generates torque
D Creates magnetic field

What is the effect of increasing the number of poles in an electrical machine?

A Increases torque
B Decreases speed
C No effect
D Increases speed

What happens to the torque in an induction motor if the slip is high?

A Torque remains constant
B Torque decreases
C Torque fluctuates
D Torque increases

How does the rotor of an induction motor receive current?

A From stator’s magnetic field
B Through commutator
C From external power supply
D Through field windings

In a DC machine, what role do the field windings play?

A Reverse current direction
B Control speed
C Generate the magnetic field
D Generate power

What is the function of the armature in a DC motor?

A Supply current
B Reverse current direction
C Create magnetic field
D Generate mechanical power

What effect does high resistance in the rotor of an induction motor have?

A Increases torque
B Decreases efficiency
C Increases speed
D Increases efficiency

In a synchronous motor, what determines the speed at which the motor operates?

A Load
B Voltage
C Rotor resistance
D Number of poles and supply frequency

How is the torque‐speed characteristic of an induction motor affected by the load?

A Torque increases with load
B Speed increases with load
C Speed remains constant
D Torque decreases with load

What is the primary purpose of the field winding in a DC generator?

A To generate electricity
B To create magnetic field
C To reverse current
D To regulate speed

What type of motor is often used in applications requiring precise position control?

A DC motor
B Synchronous motor
C Stepper motor
D Induction motor