THREE PHASE INDUCTION MOTORS QUIZ

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

Leakage reactances are increased

None of the listed here

No load current is decreased

Leakage reactances are decreased

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Bearings

Stator core

Shaft

None of these

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YOUR ANSWER : ?

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

Equal to

None of the listed here

Greater than

Smaller than

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YOUR ANSWER : ?

5 H.P., 50Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest?

2880 rpm

730 rpm

1440 rpm

1000 rpm

TRUE ANSWER : ?
YOUR ANSWER : ?

If an induction motor is running at slip S, then rotor output is ______

(S-1) × rotor input

(1-S) × rotor input

S × rotor input

(1+S) × rotor input

TRUE ANSWER : ?
YOUR ANSWER : ?

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

400 rpm

1600 rpm

2400 rpm

1200 rpm

TRUE ANSWER : ?
YOUR ANSWER : ?

The shaft of an induction motor is made of

Stainless steel

High speed steel

Carbon steel

Cast iron

TRUE ANSWER : ?
YOUR ANSWER : ?

The rotor winding of a 3phase wound rotor induction motor is generally _______ connected.

Star

Delta

Partly star and partly delta

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

In an induction motor if air gap increased

Copper loss will reduce

Windage losses will be more

Bearing friction will reduce

The power factor will be low

TRUE ANSWER : ?
YOUR ANSWER : ?

In medium sized induction motor, the slip is generally around

4 %

0.04 %

14%

0.4 %

TRUE ANSWER : ?
YOUR ANSWER : ?

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