Question

What is the period of the signal when it is time shifted?

(a) Changes according to the situation

(b) Different in different situation

(c) Remains the same

(d) Takes the shifted value

The question was asked in an internship interview.

I would like to ask this question from Fourier Series Properties topic in chapter Fourier Series of Signals and Systems

Answer 1

Correct answer is (c) Remains the same

To explain: The period of the periodic signal does not change even if it is time shifted.

If x(t) and y(t) are two periodic signals with coefficients Xn and Yn, then if a signal is shifted to t0, then the property says,

Xn = x(t-t0), Yn = Xne^-njwt0.