THREE PHASE INDUCTION MOTORS QUIZ

In a squirrel cage induction motor, the number of rotor bars is generally ________

None of the listed here

Even number

Equal to stator poles

Prime number

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When a 3-phase induction motor is at no load, the slip is ______

0.2

0.5

1

Practically zero

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One of the speeds of a 2 speed squirrel cage induction motor is 800 rpm. The other speed will be _____

400 rpm

1600 rpm

1200 rpm

2400 rpm

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Slip rings are usually made of

Aluminium

Phospor bronze

Carbon

Copper

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If the supply voltage of a 3-phase induction motor is increased two times, then torque is _______

Decreased four times

Increased two times

Decreased two times

Increased four times

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If any two phases for an induction motor are interchanged

The motor will run at reduced speed

The motor will not run

The motor will run in reverse direction

The motor will burn

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Which of the following component is usually fabricated out of silicon steel?

Shaft

Bearings

None of these

Stator core

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If the air gap between the rotor and stator of a 3-phase induction motor is increased, then_______

Leakage reactances are increased

Leakage reactances are decreased

No load current is decreased

None of the listed here

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The cogging of an induction motor can be avoided by

Having number of rotor slots more or less than the number of stator slots

Using DOL starter

Proper ventilation

Auto transformer starter

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

Commutator

Series

Slip ring

Synchronous

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