RC CIRCUITS QUIZ

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

Low resistance

high resistance

Large slip

High reactance

TRUE ANSWER : ?
YOUR ANSWER : ?

The injected e.m.f. in the rotor of induction motor must have

The same phase as the rotor e.m.f.

Zero frequency

The same frequency as the slip frequency

High value for the satisfactory speed control

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Open circuited

None of the listed here

Supplying a variable resistive load

Short circuited

TRUE ANSWER : ?
YOUR ANSWER : ?

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

No load current is decreased

Leakage reactances are increased

None of the listed here

Leakage reactances are decreased

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Changing winding resistance

Changing number of poles

Reducing supply voltage

Changing supply frequency

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Steady

None of the listed here

Rotating

Alternating

TRUE ANSWER : ?
YOUR ANSWER : ?

The shaft of induction motor is made of

Any of the listed here

Stiff

Flexible

Hollow

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 : ?

The direction of rotation of field in a 3 phase induction motor depends upon _____

Supply frequency

Phase sequence of supply voltage

Magnitude of supply voltage

Number of poles

TRUE ANSWER : ?
YOUR ANSWER : ?

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

2 cm to 4 cm

0.4 mm to 4 mm

4 cm to 6 cm

1 cm to 2 cm

TRUE ANSWER : ?
YOUR ANSWER : ?

↑