Question

In the sinusoidal response of R-L circuit, the complementary function of the solution of i is?

(a) ic = ce^-t(R/L)

(b) ic = ce^t(RL)

(c) ic = ce^-t(RL)

(d) ic = ce^t(R/L)

I have been asked this question in an interview.

This interesting question is from Sinusoidal Response of an R-L Circuit in section Transients of Network Theory

Answer 1

Correct choice is (a) ic = ce^-t(R/L)

To explain: From the R-L circuit, we get the characteristic equation as (D+R/L)i=V/L cos⁡(ωt+θ). The complementary function of the solution i is ic = ce^-t(R/L).