Question

Consider the impedance function Y(s)=(s^2+4s+3)/(3s^2+18s+24). Find the value of R1 after realizing by second Foster method.

(a) 16

(b) 12

(c) 8

(d) 4

The question was posed to me during a job interview.

This interesting question is from Synthesis of R-C Network by Foster Method topic in chapter Elements of Realizability and Synthesis of One-Port Networks of Network Theory

Answer 1

Right option is (b) 12

To elaborate: On taking the partial fractions we get P1 as 1/12. And we know that R1=1/P1. So the value of R1 is 12Ω.

R1 = 12Ω.