Electrical Machine - II (3150910) MCQs

MCQs of Single-Phase Induction Motors

Showing 41 to 40 out of 50 Questions
41.

The ______________ is modified DC Series motor.

(a)

Shaded Pole Motor

(b)

Repulsion Motor 

(c)

Repulsion Induction Motor

(d)

Universal Motor

Answer:

Option (d)

42.

Select the problems caused during if we provide AC supply to a DC series motor?

(a)

Its efficiency will poor due to hysteresis and eddy current losses

(b)

The power factor of the motor is low due to inductive reactance of the field and armature windings

(c)

The sparking at the brushes will be excessive due to the effect of armature reactance

(d)

All of these 

Answer:

Option (d)

43.

Select the modification required in the construction of Universal motor with respect to DC series motor.

(a)

Laminated Core Structure

(b)

A fewer number of turns & Increase its Thickness

(c)

Compensating Winding

(d)

All of these 

Answer:

Option (d)

44.

Select the proper Problem-solution combination during Universal motor modified from the DC Series Motor.

Problem Solution
1. Its efficiency will poor due to hysteresis and eddy current losses 1. Use – Compensating Winding
2. Power factor of the motor is low due to inductive reactance of the field and armature windings 2. Use – Laminated Core Structure
3. The sparking at the brushes will be excessive due to the effect of armature reactance 3. Use – Reduced number of turns & Increase it Thickness
(a)

1-1,   2-2,   3-3

(b)

1-2,   2-3,   3-3

(c)

1-2,   2-3,   3-1

(d)

1-3,   2-1,   3-2

Answer:

Option (c)

45.

What is the role of Compensating winding in the universal motor?

(a)

To reduced the sparking at the brushes 

(b)

to improve power factor

(c)

to improve efficiency 

(d)

All of these 

Answer:

Option (d)

46.

The compensating winding in universal motor is connected in ______________ with armature winding and in _______________ with field winding.

(a)

Series,         Series

(b)

Series,         Parallel 

(c)

Parallel,         Series

(d)

Parallel,         Parallel

Answer:

Option (a)

47.

In the universal motor, The compensated winding is placed in the slots at _______________ with the main field axis.

(a)

90˚ Electrically

(b)

90˚ Mechanically

(c)

180˚ Electrically

(d)

180˚ Mechanically

Answer:

Option (a)

48.

In the very small ratting universal motor, Which of the following thing is not required?

(a)

Laminated Core 

(b)

Commutator and Brushes 

(c)

Compensating Winding 

(d)

All of these 

Answer:

Option (c)

49.

What are the disadvantage/s of single-phase induction motor with respect to three-phase induction motor?

(a)

an ununiform rotating magnetic field 

(b)

Not-Self Started

(c)

Poor efficiency & power factor

(d)

All of these 

Answer:

Option (d)

50.

What are the advantage/s of single-phase induction motor with respect to three-phase induction motor?

(a)

Simple construction & reliable 

(b)

easy to repair & maintain

(c)

economical 

(d)

All of these 

Answer:

Option (d)

Showing 41 to 40 out of 50 Questions