Electrical Machine - II (3150910) MCQs

MCQs of Single-Phase Induction Motors

Showing 31 to 40 out of 50 Questions
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31.

If a single-phase induction motor runs slower than normal, the most likely defect is

(a)

Worn bearing
(b)

Open circuit winding
(c)

Short circuit winding
(d)

faulty centrifugal switch 
Answer:

Option (a)

32.

If starting winding of a single-phase induction motor not connected during starting?

(a)

Damage the starting winding
(b)

Damage the running winding
(c)

nothing will happen 
(d)

the motor operates with a lower speed 
Answer:

Option (b)

33.

__________ motors have two separate rotor windings.

(a)

Repulsion motor
(b)

Capacitor start capacitor run motor
(c)

Repulsion start induction run motor
(d)

shaded pole motor
Answer:

Option (c)

34.

A shaded pole motor is Cheaper, Simpler, Extremely Rugged & Reliable because it does not have _________

(a)

Commutator
(b)

Capacitor
(c)

Centrifugal switch
(d)

Commutator, Capacitor, & Centrifugal switch
Answer:

Option (d)

35.

If a D.C. series motor is operated on A.C. supply, it will have

(a)

Poor power factor
(b)

Poor efficiency
(c)

Spark excessively
(d)

All of these
Answer:

Option (d)

36.

The capacitors used in single-phase capacitor motors have no

(a)

Dielectric medium
(b)

Polarity Marking
(c)

Voltage Rating
(d)

All of these 
Answer:

Option (b)

37.

The single-phase induction motor is alway operate at ______________ power factor.

(a)

Lagging
(b)

Leading
(c)

Unity
(d)

90 degree lagging 
Answer:

Option (a)

38.

When a D.C. series motor is connected to A.C. supply, the power factor will be low because of

(a)

The fine copper wire winding
(b)

The induced current in rotor due to variations of flux
(c)

High inductance of field and armature circuits
(d)

None of the above
Answer:

Option (c)

39.

Which capacitor has a higher value?

(a)

Starting Capacitor
(b)

Running Capacitor
(c)

Both Starting and Running Capacitor
(d)

neither starting nor running 
Answer:

Option (a)

40.

Which of the following single-phase motor can work on both AC or DC supply?

(a)

DC Series Motor
(b)

Repulsion Motor
(c)

Universal Motor
(d)

Shaded Pole Motor 
Answer:

Option (c)

Showing 31 to 40 out of 50 Questions
1 2 3 4 5