THREE PHASE INDUCTION MOTORS QUIZ

If the frequency of 3-phase supply to the stator of a 3-phase induction motor is increased, then synchronous speed ______

Is decreased

Remains unchanged

Is increased

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

The torque developed in the cage induction motor with auto-starter is

k2/torque with direct switching

k/torque with direct switching

K Ã— torque with direct switching

K2 Ã— torque with direct switching

TRUE ANSWER : ?
YOUR ANSWER : ?

The starting torque of a 3-phase induction motor is _______ supply voltage.

Directly proportional to

None of the listed here

Directly proportional to sqaure of

Independent of

TRUE ANSWER : ?
YOUR ANSWER : ?

A 3 phase induction motor is ________

Essentially a constant speed motor

A variable speed motor

Not easily maintainable

Very costly

TRUE ANSWER : ?
YOUR ANSWER : ?

3-phase wound rotor morors are also called _____ motors.

Commutator

Synchronous

Series

Slip ring

TRUE ANSWER : ?
YOUR ANSWER : ?

In medium sized induction motor, the slip is generally around

0.04 %

0.4 %

14%

4 %

TRUE ANSWER : ?
YOUR ANSWER : ?

In a 3 phase induction motor, the rotor speed is _____ the synchronous speed.

None of the listed here

Smaller than

Equal to

Greater than

TRUE ANSWER : ?
YOUR ANSWER : ?

When the rotor of a 3-phase induction motor is blocked, the slip is _____

0.5

1

0

0.1

TRUE ANSWER : ?
YOUR ANSWER : ?

Friction and windage loss of a 3 phase induction motor are

Maximum at no load

None of the listed here

Remains the same at all loads

Minimum at no load

TRUE ANSWER : ?
YOUR ANSWER : ?

The crawling in an induction motor is caused by

Low voltage supply

Harmonics developed in the rotor

Improper design of machine

High loads

TRUE ANSWER : ?
YOUR ANSWER : ?

↑