Question

The impedance of the last two elements in the parallel combination after transformation in the circuit shown below is?

(a) 1/(s+4)

(b) 1/(s+3)

(c) 1/(s+2)

(d) 1/(s+1)

I have been asked this question in an interview for internship.

Origin of the question is Series and Parallel Combination of Elements topic in division S-Domain Analysis of Network Theory

Answer 1

The correct choice is (a) 1/(s+4)

Easiest explanation: The impedance of resistor is 4Ω and the impedance of capacitor is s. So the impedance of the last two elements in the parallel combination is Z1(s) = 1/(s+4).