Electrical Machines
In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is

 1, 2, 3, 4
 1, 3, 5
 2, 3, 4
 1, 2, 5

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The 3 - Φ induction motors are, by a very considerable margin, the most widely used AC motors as

  these are cheaper in cost, simple and rugged in construction.
  they have very good speed regulation.
  they have maximum efficiency and maximum starting torque.
  they are capable of operation under range of leading and lagging pf.

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Electrical Machines