Electrical Machines
An ideal synchronous motor has no starting torque because

  relative velocity between stator and rotor mmf’s is not zero.
 rotor winding is highly reactive.
 rotor is made up of salient poles.
 relative velocity between the stator and rotor mmf’s is zero.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is

 1, 4, 6
 1, 2, 5
 1, 3, 5
 1, 2, 6

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The synchronous motor can be started by

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

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Electrical Machines