Q 12-07-020NEETJEE MainTop questionMedium
A series circuit has $R = 30\ \Omega$, $X_L = 60\ \Omega$ and $X_C = 20\ \Omega$ across a $100$ V (rms) supply. The rms current and power factor are
Answer: (C) $2$ A and $0.6$
Concept. $Z = \sqrt{R^2 + (X_L - X_C)^2}$, $I = \dfrac{V}{Z}$, power factor $\dfrac{R}{Z}$.
Step 1. Impedance. $Z = \sqrt{30^2 + 40^2} = 50\ \Omega$.
Step 2. Current. $\dfrac{100}{50} = 2$ A.
Step 3. Power factor. $\dfrac{30}{50} = 0.6$.
Answer. $2$ A and $0.6$ (Option C).
Solution by Sreeraj P, M.Sc Physics