Electrical Machines
The crawling in the induction motor is caused by

 high loads
 improper design of stator laminations
 harmonics developed in the motor
 low voltage supply

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The synchronous motor can be started by

  providing damper winding in its rotor circuit.
  coupling it with a small AC induction motor called the pony motor.
  any of the above methods.
  coupling it with a DC compound motor.

ANSWER DOWNLOAD EXAMIANS APP