Question

The characteristic equation of a system is given ass3+25s2+10s+50=0. What is the number of the roots in the right half s-plane and the imaginary axis respectively?

(a) 1,1

(b) 0,0

(c) 2,1

(d) 1,2

The question was posed to me in unit test.

Origin of the question is Routh-Hurwitz Stability Criterion topic in chapter Stability and Algebraic Criteria of Control Systems

Answer 1

The correct option is (b) 0,0

To elaborate: The characteristic equation has no sign changes so number of roots on the right half of s plane is zero.