• summary_type: concept
• word_count: 170

At resonance, X_L = X_C, giving omega_0 = 1/sqrt(LC) and f_0 = 1/(2pisqrt(LC)). The impedance reduces to Z = R (minimum), current reaches maximum I = V/R, and the phase angle is zero (purely resistive). The quality factor Q = omega_0*L/R = (1/R)sqrt(L/C) determines the sharpness of the resonance peak. Higher Q means narrower bandwidth (Delta_omega = R/L = omega_0/Q) and greater voltage magnification: V_L = V_C = QV at resonance. These voltages can greatly exceed the source voltage — this is not an error but a real physical phenomenon. The energy oscillates between L (magnetic) and C (electric) with no net dissipation in the reactive elements. Changing R affects the peak height and width but not the resonant frequency. Changing L or C shifts the resonant frequency. Radio tuning uses a variable capacitor to adjust f_0.