Question

The transfer function of a system is given by Y(s)/X(s) = e^−0.1s/1+s. If x(t) is 0.5sint, then the phase angle between the output and the input will be:

(a) -39.27°

(b) -45°

(c) -50.73°

(d) -90°

The question was posed to me during an interview.

The question is from Correlation between Time and Frequency Response in portion Frequency Response Analysis of Control Systems

Answer 1

Right choice is (c) -50.73°

To elaborate: Phase angle = -tan^−1-0.1*180°/π

w =1 rad/sec

Phase angle =-50.73°.