Question

Calculate the total heat dissipated in a resistor of 44 Ω when 0 A current flows through it.

(a) 0 W

(b) 2 W

(c) 1.5 W

(d) .3 W

This question was addressed to me in an interview for internship.

Question is taken from Induction Motors Speed Control in section Speed Control of Direct Current Motors & Induction Motors of Electric Drives

Answer 1

Correct option is (a) 0 W

The explanation is: The resistor is a linear element. It only absorbs real power and dissipates it in the form of heat. The voltage and current are in the same phase in case of the resistor so the angle between V & I is 90°. P=I^2R=0×0×44=0 W.