Q 12-07-034JEE MainJEE Main 2026 (6 Apr, Shift 1)Easy
A LCR series circuit driven with $E_{rms} = 90$ V at frequency $f_d = 30$ Hz has resistance $R = 80\ \Omega$, an inductance with inductive reactance $X_L = 20.0\ \Omega$ and capacitance with capacitive reactance $X_C = 80.0\ \Omega$. The power factor of the circuit is ______.
Answer: (A) $0.8$
$Z = \sqrt{R^2 + (X_C - X_L)^2} = \sqrt{80^2 + 60^2} = 100\ \Omega$.
Power factor $= \dfrac{R}{Z} = 0.8$.
Solution by Sreeraj P, M.Sc Physics