Which, among the following, is the correct expression for φ.
(a) φ=tan^-1 (XL/R)
(b) φ=tan^-1 (R/XL)
(c) φ=tan^-1 (XL*R)
(d) φ=cos^-1 (XL/R)
I had been asked this question in an online interview.
This interesting question is from Resistance and Inductance in Series topic in chapter Single Phase Series Circuits of Basic Electrical Engineering