Q. 39 A certain system has transfer function
where 
is a parameter. Consider the standard negative unity feedback
configuration as shown below
Which of the following statements is true?
(A) The closed loop systems is never stable for any value of a
(B) For some positive value of a, the closed loop system is stable, but not for all positive values.
(C) For all positive values of a, the closed loop system is stable.
(D) The closed loop system stable for all values of a, both positive and
negative.
Answer: C
Explanation:
