Question

Determine the driving point impedance Z11(S) in the circuit shown below.

(a) (8 S+4)/(4 S+4)

(b) (8 S+4)/(4 S+3)

(c) (8 S+4)/(4 S+2)

(d) (8 S+4)/(4 S+1)

I got this question in semester exam.

This interesting question is from Network Function for the One-Port and Two-Port topic in division S-Domain Analysis of Network Theory

Answer 1

Correct option is (d) (8 S+4)/(4 S+1)

To elaborate: The driving point impedance Z11(S) is Z11(S) = V1(s)/I1(s). V1(s) = I1(s)((2/(4s+1))+2) = I1(s)((8s+4)/(4s+1)) => V1(s)/I1(s) = ((8s+4)/(4s+1)). On substituting we get Z11(S) = (8S+4)/(4S+1).