CP9.10 A closed-loop feedback system is shown in Figure CP9.10.

(a) Obtain the Nyquist plot and determine the phase margin. Assume that the time delay T = 0 s.

(b) Compute the phase margin when T = 0.05 s.

(c) Determine the minimum time delay that destabilizes the closed-loop system.

R(s) Time delay Y(s) s+ 10 S FIGURE CP9.10 Nonunity feedback system with a time delay.