Electrical Machines
An ideal synchronous motor has no starting torque because

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

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Armature reaction in a DC machine

 is in direct opposition to the main poles.
 is in the same direction as the main poles.
  makes an angle of 90° with the main pole axis.
 makes an angle with the main pole axis which is load dependent.

ANSWER DOWNLOAD EXAMIANS APP