# Induction Motor MCQs Part 11

Induction Motor MCQs Part 11

## 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:

1. 4% in the rotor torque
2. 8% in the rotor torque
3. 16% in the rotor torque
4. 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 1.042 = 1.08 times which in other terms is 8%.

## 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:

1. High starting torque
2. Slow speed operation
3. Low windage losses
4. 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:

1. Motor-generator set
2. Coreless transformers
3. Multiphase transformer
4. Current transformers

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:

1. S.n
2. Ns
3. (ns-l) s
4. (l-s) ns