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) $0.8$
Concept. Power factor $\cos\phi=\dfrac RZ$.
Step 1. Impedance. $\sqrt{80^2+60^2}=100\ \Omega$.
Answer. $0.8$ (Option A).
Solution by Sreeraj P, M.Sc Physics
