Question

What is the spectrum that is obtained when we plot |ck| as a function of frequency?

(a) Magnitude voltage spectrum

(b) Phase spectrum

(c) Power spectrum

(d) None of the mentioned

This question was addressed to me during a job interview.

I need to ask this question from Frequency Analysis of Continuous Time Signal topic in chapter Frequency Analysis of Signals and Systems of Digital Signal Processing

Answer 1

The correct choice is (a) Magnitude voltage spectrum

The explanation: We know that, Fourier series coefficients are complex valued, so we can represent ck in the following way.

ck=|ck|e^jθk

When we plot |ck| as a function of frequency, the spectrum thus obtained is known as Magnitude voltage spectrum.