Question

A driving point impedance with pole at ω = 0 and zero at ω = ∞ must have ___________ term in the denominator polynomial.

(a) s

(b) s+3

(c) s+1

(d) s+2

The question was asked during an interview.

This intriguing question comes from Frequency Response of Reactive One-Ports in chapter Elements of Realizability and Synthesis of One-Port Networks of Network Theory

Answer 1

Right answer is (a) s

Explanation: s-jω = (s-j(0)) = s. As pole is at ω = 0, there will be s term in the denominator polynomial.