• summary_type: concept
• word_count: 150

A charged capacitor connected to an inductor creates LC oscillations at omega = 1/sqrt(LC). The energy shuttles between electric (Q^2/(2C)) and magnetic (LI^2/2) forms, with total energy constant: Q^2/(2C) + LI^2/2 = Q_0^2/(2C). This is mathematically identical to a spring-mass system: L corresponds to mass m, 1/C to spring constant k, Q to displacement x, and I to velocity v. When Q = Q_0 (maximum charge), I = 0. When Q = 0, I = I_0 = Q_0/(sqrt(LC)) (maximum current). The oscillation period T = 2pisqrt(LC). In practice, resistance causes damped oscillations — energy is gradually lost to heat. A driven LC circuit with small R shows resonance when the driving frequency matches the natural frequency 1/sqrt(LC). This is the principle behind radio tuning circuits.