In a squirrel cage motor the induced e.m.f. is___________?

A. Dependent on the shaft loading
B. Dependent on the number of slots
C. Slip times the stand still e.m.f. induced in the rotor
D. None of the above

The purpose of using short-circuit gear is___________?

A. To short circuit the rotor at slip rings
B. To short circuit the starting resistances in the starter
C. To short circuit the stator phase of motor to form star
D. None of the above

Temperature of the stator winding of a three phase induction motor is obtained by___________?

A. Resistance rise method
B. Thermometer method
C. Embedded temperature method
D. All above methods

For driving high inertia loads best type of induction motor suggested is_____________?

A. Slip ring type
B. Squirrel cage type
C. Any of the above
D. None of the above

Insertion of resistance in the rotor of an induction motor to develop a given torque?

A. Decreases the rotor current
B. Increases the rotor current
C. Rotor current becomes zero
D. Rotor current rernains same

Insertion of reactance in the rotor circuit_______?

A. Reduces starting torque as well as maximum torque
B. Increases starting torque as well as maximum torque
C. Increases starting torque but maxi-mum torque remains unchanged
D. Increases starting torque but maxi-mum torque decreases

Lubricant used for ball bearing is usually___________?

A. Graphite
B. Grease
C. Mineral oil
D. Molasses

An induction motor can run at synchronous speed when____________?

A. It is run on load
B. It is run in reverse direction
C. It is run on voltage higher than the rated voltage
D. E.m.f. is injected in the rotor circuit

The low power factor of induction motor is due to___________?

A. Rotor leakage reactance
B. Stator reactance
C. The reactive lagging magnetizing current necessary to generate the magnetic flux
D. All of the above

In induction motor, percentage slip depends on__________?

A. Supply frequency
B. Supply voltage
C. Copper losses in motor
D. None of the above