Question

What is the noise to signal ratio if the phase shift introduced by noise is 0.75°?

(a) 0.5

(b) 0.966

(c) 0.25

(d) 1.75

This question was addressed to me in an online quiz.

I'd like to ask this question from Noise Suppression Effects of FM in division Amplitude & Frequency Modulation of Avionics

Answer 1

Right choice is (b) 0.966

The explanation is: ɸ=sin^-1(N/S)

         (N/S)=sin(ɸ) =sin(75°)=0.966.