Question

Which of the following should be done to make an unstable system stable?

(a) The gain of the system should be decreased

(b) The gain of the system should be increased

(c) The number of poles to the loop transfer function should be increased

(d) The number of zeros to the loop transfer function should be increased

I had been asked this question during a job interview.

Question is from Parameter Optimization : Servomechanims in portion Optimal Control Systems of Control Systems

Answer 1

Right option is (b) The gain of the system should be increased

The best explanation: The gain of the system should be increased to make an unstable system stable and for positive feedback of the system the gain is more and for the negative feedback the gain is reduced for which the stable system can become unstable.