Electrical Machines
A DC series motor must started on no load because it would

 Draw more current without producing sufficient torque.
 Fail to start without load.
  Run at dangerously high speed.
 Not develop starting torque.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
The mmf produced by rotor currents of a 3 - Φ induction motor

  rotates at synchronous speed with respect to rotor.
  rotates at the speed of rotor in the air gap.
  is at standstill with respect to stator mmf.
  rotates at slip speed with respect to stator mmf.

ANSWER DOWNLOAD EXAMIANS APP