 Inductor voltage magnification in a series RLC circuit

For series resistance $R$, inductance $L$ and capacitance $C$, with output measured across the inductor, the $e^{i\omega t}$ transfer function is $H_L=i\omega L/[R+i(\omega L-1/(\omega C))]$. At current resonance ${\omega }_0=1/\sqrt{LC}$ its modulus is ${\omega }_{0}L/R=Q$. Large and oppositely phased inductor and capacitor voltages nearly cancel in the loop sum. This is voltage magnification in a passive circuit, not power gain. The maximum of $|H_L|$ need not occur exactly at the current-resonance frequency.