Question

A periodic signal has power \(\frac{P}{4}\) equal to average energy per period then rms value of signal is given by ________________

(a) \(\frac{\sqrt{P}}{4}\)

(b) \(\frac{P}{4}\)

(c) \(\frac{P}{2}\)

(d) \(\frac{\sqrt{P}}{2}\)

I got this question by my school principal while I was bunking the class.

Origin of the question is Average Power and Energy of a Signal topic in division Fourier Series of Signals and Systems

Answer 1

Right answer is (d) \(\frac{\sqrt{P}}{2}\)

The explanation is: For an energy signal if the average energy per period is P, then the rms value which corresponds to a DC signal is equal to \(\sqrt{P}\).

∴ \(\frac{P}{4}\) –> x(t), then xrms (t) –> \(\frac{\sqrt{P}}{2}\).