Electrical Machines
The rotor speed of an induction motor is given by

  Ns = 120f /p × ( 1 - r).
  Ns = 120f / p × ( 1 - s ).
  Nr = 120f / p × (1-s).
None of these

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
With the increase in speed of a DC motor

 both back emf as well as line current increase.
 back emf falls and line current increases.
 back emf increases but line current falls.
 both back emf as well as line current fall.

ANSWER DOWNLOAD EXAMIANS APP