Question

R.M.S value of the periodic square waveform of amplitude 20 V is _______

(a) 20 V

(b) 18 V

(c) 17 V

(d) 13 V

The question was asked by my college director while I was bunking the class.

This key question is from Induction Motors topic in chapter Speed Control of Direct Current Motors & Induction Motors of Electric Drives

Answer 1

Correct answer is (a) 20 V

Explanation: R.M.S value of the periodic square waveform is Vm and r.m.s value of the trapezoidal waveform is Vm÷3^½. The peak value of the periodic square waveform is Vm. Vm=20 V.