Question

If induction motor air gap power is 10 KW and mechanically developed power is 8 KW, then rotor ohmic loss will be _________ KW.

(a) 1

(b) 2

(c) 3

(d) 4

This question was addressed to me in class test.

The doubt is from Speed Control of Shunt or Separately Excited Motors in chapter Speed Control of Direct Current Motors & Induction Motors of Electric Drives

Answer 1

The correct option is (b) 2

The best explanation: Rotor ohmic losses are due to the resistance of armature windings. Net input power to the rotor is equal to the sum of rotor ohmic losses and mechanically developed power. Rotor ohmic losses=Air gap power-Mechanical developed power=10-8=2 KW.