Electrical Machines
An ideal synchronous motor has no starting torque because

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

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Which of the following represents the commutator pitch?

 The distance between the staring of first coil and its next successive coil
 Number of conductors spanned by one coil at the back end of the armature.
 Number of commutator segments between two successive coils.
 Number of conductors spanned by one coil at the front end of the armature.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
For satisfactory parallel operation of two transformers which of the following conditions is most essential,

  polarities of all transformers must be same.
 voltage ratio of all transformers must be same.
 MVA rating of all transformer inversely proportional to impedance.
 percentage impedance of all transformers must be same.

ANSWER DOWNLOAD EXAMIANS APP