THREE PHASE INDUCTION MOTORS QUIZ

At no load the rotor core loss of a 3 phase induction motor is

None of the listed here

Practically zero

Small

Large

TRUE ANSWER : ?
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In a squirrel cage induction motor, the number of rotor bars is generally ________

Equal to stator poles

Even number

Prime number

None of the listed here

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The advantage of wound rotor motor is that _______

External resistance can be inserted in the rotor circuit

None of the listed here

It requires less maintenance

It is inexpensive

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The speed of a squirrel-cage induction motor can be controlled by all of the following except

Reducing supply voltage

Changing winding resistance

Changing supply frequency

Changing number of poles

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Less maintenance troubles are experienced in case of

Both (A) and (B)

Squirrel cage induction motor

None of these

Slip ring induction motor

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The term cogging is associated with

Induction motors

Dc series motors

Three phase transformer

Compound generators

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If any two phases for an induction motor are interchanged

The motor will burn

The motor will not run

The motor will run at reduced speed

The motor will run in reverse direction

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A 3 phase induction motor is running at 2% slip. If the input to rotor is 1000 W, then mechanical power developed by the motor is _______

200 W

20 W

980 W

500 W

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In an induction motor if air gap increased

Bearing friction will reduce

Windage losses will be more

The power factor will be low

Copper loss will reduce

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The 3- phase induction motor is so designed that the rotor should have ______ under running conditions.

Low resistance

high resistance

High reactance

Large slip

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YOUR ANSWER : ?

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