THREE PHASE INDUCTION MOTORS QUIZ

The condition of induction motor at stand still resemble those of a transformer whose secondady is _______

None of the listed here

Supplying a variable resistive load

Open circuited

Short circuited

TRUE ANSWER : ?
YOUR ANSWER : ?

In an induction motor, the ratio of rotor cu loss and rotor input is given by

1-S

S

S/1-S

1/S

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Even number

None of the listed here

Equal to stator poles

Prime number

TRUE ANSWER : ?
YOUR ANSWER : ?

The maximum torque in an induction motor depends on

Frequency

All of the listed here

Rotor inductive reactance

Square of supply voltage

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Less rotor losses

None of the listed here

Greater mechanical strength

Uniform torque

TRUE ANSWER : ?
YOUR ANSWER : ?

An induction motor is so called because its operation depends on

Self induction

Mutual induction

Hysteresis

Eddy currents

TRUE ANSWER : ?
YOUR ANSWER : ?

The speed of a squirrel cage induction motor is changed by

Cascade control

Pole changing

Rheostatic control

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

The induction motor has lagging power factor during

Both starting and operation

Starting only

None of the listed here

Operation only

TRUE ANSWER : ?
YOUR ANSWER : ?

The low power factor of induction motor is due to

Rotor leakage reactance

The reactive lagging magnetizing current necessary to generate the magnetic flux

All of these

Stator reactance

TRUE ANSWER : ?
YOUR ANSWER : ?

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 _______

500 W

20 W

200 W

980 W

TRUE ANSWER : ?
YOUR ANSWER : ?

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