Question

The main objective of drawing root locus plot is :

(a) To obtain a clear picture about the open loop poles and zeroes of the system

(b) To obtain a clear picture about the transient response of feedback system for various values of open loop gain K

(c) To determine sufficient condition for the value of ‘K’ that will make the feedback system unstable

(d) Both b and c

I had been asked this question in exam.

Question is taken from The Root Locus Concepts topic in chapter The Root Locus Technique of Control Systems

Answer 1

The correct option is (d) Both b and c

For explanation I would say: The main objective of drawing root locus plot is to obtain a clear picture about the transient response of feedback system for various values of open loop gain K and to determine sufficient condition for the value of ‘K’ that will make the feedback system unstable.