57) What happens to the rotor of a 3 phase induction motor if its speed attains to synchronous speed?

Rotor speed reduces

Rotor speed increases

Rotor speed remains same

Rotor bars get damaged

Answer is:

Rotor bars get damaged

Motor does not start

Over heating in motor

Excess vibration of shaft

Motor runs with very low speed

Answer is:

Improper earthing

Over loading of motor

Heavy voltage fluctuation

Poor insulation in winding

Answer is:

Motor runs and stop immediately

Motor runs in slow speed continuously

Motor runs and draws more current

Motor continues to run with irregular speed

Answer is:

Incorrect fuse ratings

Unbalanced line voltage

Incorrect settings of OLR

Improper phase sequence

Answer is: