THREE PHASE INDUCTION MOTORS QUIZ

The air gap between stator and rotor of 3-phase induction motor ranges from ______

0.4 mm to 4 mm

1 cm to 2 cm

4 cm to 6 cm

2 cm to 4 cm

TRUE ANSWER : ?
YOUR ANSWER : ?

Less maintenance troubles are experienced in case of

Slip ring induction motor

Both (A) and (B)

Squirrel cage induction motor

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

A four speed squirrel cage induction motor uses______ stator windings.

Two

Four

One

Three

TRUE ANSWER : ?
YOUR ANSWER : ?

An induction motor is preferred to a dc motor because it _______

Has simple and rugged construction

Provides fine speed control

None of the listed here

Provides high starting torque

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Open circuited

Short circuited

Supplying a variable resistive load

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

Very large 3-phase induction motors (greater than 25 HP) are started _____

Direct on line

Star-delta starting

By auto transformer starting

None of the listed here

TRUE ANSWER : ?
YOUR ANSWER : ?

The full load slip of a 3-phase induction motor ranges from

2 to 5 %

None of the listed here

10 to 20 %

20 to 30 %

TRUE ANSWER : ?
YOUR ANSWER : ?

DOL starting of induction motors is usually restricted to

High horsepower motors

Variable speed motors

Low horsepower motors

High speed motors

TRUE ANSWER : ?
YOUR ANSWER : ?

The synchronous speed of a 3-phase induction motor having 20 poles and connected to a 50 Hz source is _____

1000 rpm

600 rpm

300 rpm

1200 rpm

TRUE ANSWER : ?
YOUR ANSWER : ?

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

1200 rpm

2400 rpm

400 rpm

1600 rpm

TRUE ANSWER : ?
YOUR ANSWER : ?

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