7. A position control system can be analyzed using the feedback system in Figure 10.38,

where the process transfer function is

5 G(s): = s(s+1)(0.4s+1) A phase-lag compensator that provides a phase margin of P.M. 30 is: 1+s a. G(s)= 1+106s b. G(s) = 1+26s 1+115s 1+106s c. G(s) = 1+118s d. None of the above