Question

In regenerating the feedback, the transfer function is given by

(a) C(s)/R(s)=G(s)/1+G(s)H(s)

(b) C(s)/R(s)=G(s)H(s)/1-G(s)H(s)

(c) C(s)/R(s)=G(s)/1+G(s)H(s)

(d) C(s)/R(s)=G(s)/1-G(s)H(s)

I had been asked this question in unit test.

The query is from Transfer Functions topic in chapter Mathematical Models of Physical Systems of Control Systems

Answer 1

Correct option is (d) C(s)/R(s)=G(s)/1-G(s)H(s)

Easiest explanation: Regenerating feedback is positive feedback  and it increases the infinitely and hence the speed of response of the system reduces.