In the circuit shown, inductance of the inductor L = 100 mH. Then average magnetic energy stored in the inductor is

Z=R2+XL2=302+402 Ω=50Ω∴ rms current, I=100/250A=2A∴ Average magnetic energy stored in the inductor U=12L I2=12×100×10−3×22J=0.1J