LC Oscillating Circuit
An inductor and a capacitor connected together trade energy back and forth indefinitely, and this simulation shows that exchange as it happens. Charge sloshes between the capacitor plates while current builds and collapses in the coil, with the energy bar chart tracking where the energy sits at each instant.
How to use this simulation
- Adjust the capacitance C and the inductance L
- Set the initial charge on the capacitor
- Add resistance to see the oscillation decay
What to look for
- Current peaks exactly when the capacitor voltage is zero, and vice versa — they are a quarter cycle out of step
- Total energy stays constant when there is no resistance
- Raising either L or C lengthens the period, following the square-root relationship
The physics behind it
Energy alternates between the capacitor's electric field, ½CV², and the inductor's magnetic field, ½LI². The circuit oscillates at its natural frequency f = 1/(2π√(LC)), the direct electrical analogue of a mass bouncing on a spring, where L plays the role of mass and 1/C the role of the spring constant.