Question

If the gain of the system is reduced to a zero value, the roots of the system in the s-plane,

(a) Coincide with zero

(b) Move away from zero

(c) Move away from poles

(d) Coincide with the poles

The question was asked at a job interview.

I'm obligated to ask this question of The Root Locus topic in chapter The Root Locus Technique of Control Systems

Answer 1

Correct answer is (d) Coincide with the poles

To explain: The roots of the system in s plane coincides with the poles if the gain of the system is reduced to a value zero.