Induction Motor MCQs Part 11

Contents

- 1 A change of 4% of supply voltage to an induction motor will accordingly produce a change of approximately
- 2 As compared to squirrel cage induction motor, a wound rotor induction motor is preferred for
- 3 High frequency power supply for induction furnaces can be obtained using
- 4 In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be expressed mathematically

## A change of 4% of supply voltage to an induction motor will accordingly produce a change of approximately

A change of 4% of supply voltage to an induction motor will accordingly produce a change of approximately:

- 4% in the rotor torque
- 8% in the rotor torque
- 16% in the rotor torque
- 2% in the rotor torque

Correct answer: 2. 8% in the rotor torque

Explanation: Torque that can be delivered by the induction motor is proportional to the square of the operating voltage. When the supply voltage increases by 4%, it becomes 1.04 times the original value and therefore torque becomes 1.04^{2} = 1.08 times which in other terms is 8%.

Also read: Induction motor construction

## As compared to squirrel cage induction motor, a wound rotor induction motor is preferred for

As compared to squirrel cage induction motor, a wound rotor induction motor is preferred for:

- High starting torque
- Slow speed operation
- Low windage losses
- All of the above

Correct answer: 1. High starting torque

Also See: Induction motor formulas

## High frequency power supply for induction furnaces can be obtained using

High frequency power supply for induction furnaces can be obtained using:

- Motor-generator set
- Coreless transformers
- Multiphase transformer
- Current transformers

Correct answer: 1. Motor-generator set

You might be interested in: Top 10 Differences: Difference Between Induction and Synchronous Motors

## In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be expressed mathematically

In Ns is the synchronous speed and s the slip, then the actual running speed of an induction motor will be expressed mathematically:

- S.n
- Ns
- (ns-l) s
- (l-s) ns

Correct answer: 4. (l-s) ns

More MCQs on Induction motor:

- Induction Motor MCQs Part 1
- Induction Motor MCQs Part 2
- Induction Motor MCQs Part 3
- Induction Motor MCQs Part 4
- Induction Motor MCQs part 5
- Induction Motor MCQs Part 6
- Induction Motor MCQs Part 7
- Induction Motor MCQs Part 8
- Induction Motor MCQs Part 9
- Induction Motor MCQs Part 10