Question

If the phase ϴ(ω) of the system is linear, then the group delay of the system?

(a) Increases with frequency of signal

(b) Constant

(c) Decreases with frequency of signal

(d) Independent of frequency of signal

I have been asked this question in an interview for internship.

The above asked question is from LTI System as Frequency Selective Filters in division Frequency Analysis of Signals and Systems of Digital Signal Processing

Answer 1

Right option is (b) Constant

Explanation: We know that the group delay of the system with phase ϴ(ω) is defined as

Tg(ω)=\(\frac{dϴ(ω)}{dω}\)

Given the phase is linear=> the group delay of the system is constant.