Question

Non-linear elements may exhibit___________

(a) Linear systems

(b) Non-linear systems

(c) Limit cycles

(d) Time invariant systems

This question was addressed to me in an interview.

The question is from Necessary Conditions for Stability and Non-Linear Systems topic in division Stability and Algebraic Criteria of Control Systems

Answer 1

Right option is (c) Limit cycles

The best explanation: Non-linear elements may exhibit the limit cycles which are self-sustained oscillations of fixed frequency and amplitude. Determination of existence of limit cycles is not an easy task as these may depend upon both the type and amplitude of the excitation signal.