THREE PHASE INDUCTION MOTORS QUIZ

The starting torque of an induction motor is maximum when rotor resistance per phase is _____ rotor reactance / phase.

Two times

Four times

Equal to

None of the listed here

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YOUR ANSWER : ?

The cogging of an induction motor can be avoided by

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

Auto transformer starter

Proper ventilation

Using DOL starter

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YOUR ANSWER : ?

The speed of a squirrel cage induction motor is changed by

None of the listed here

Cascade control

Rheostatic control

Pole changing

TRUE ANSWER : ?
YOUR ANSWER : ?

The stator of a three phase induction motor produces _______ magnetic field.

Rotating

Alternating

Steady

None of the listed here

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YOUR ANSWER : ?

A 3 phase induction motor is ________

Very costly

Essentially a constant speed motor

Not easily maintainable

A variable speed motor

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The frame of an induction motor is usually made of

Aluminium

Cast iron

Silicon steel

Bronze

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YOUR ANSWER : ?

The approximate efficiency of a 3-phase , 50 Hz, 4 pole induction motor running at 1350 rpm is ______

None of the listed here

40%

65%

90%

TRUE ANSWER : ?
YOUR ANSWER : ?

A 3 phase 440 v, 50 Hz induction motor has 4% slip. The frequency of rotor emf will be

20 Hz

2 Hz

200 Hz

50 Hz

TRUE ANSWER : ?
YOUR ANSWER : ?

The shaft of an induction motor is made of

Carbon steel

High speed steel

Stainless steel

Cast iron

TRUE ANSWER : ?
YOUR ANSWER : ?

In a squirrel cage rotor, the bars are not placed parallel to the shaft but are skewed to have ______

Uniform torque

None of the listed here

Less rotor losses

Greater mechanical strength

TRUE ANSWER : ?
YOUR ANSWER : ?

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