This Java applet shows a simple circuit consisting of an alternating voltage source and, depending on the selected radio button, a resistor (without inductivity), a capacitor or an ideal coil (without resistance). In addition there are meters for the voltage U (blue) and the amperage I (red).

Below the drawing of the circuit you see on the left a phasor diagram; it is possible to read the momentary oscillation phases from the position of the two phasors (voltage blue, amperage red). The projection of a phasor onto the horizontal axis corresponds to the momentary value of U respectively I. On the bottom right the dependence of voltage and amperage on the time is illustrated in a diagram.

The "Reset" button brings the circuit to its initial state. You can start or stop and continue the simulation with the other two buttons. If you choose the option "Slow motion", the movement will be five times slower.

It is possible to vary the preselected values of frequency, maximal voltage and resistance respectively capacity or inductivity. The program will indicate the new value of the maximal amperage.

Physics Applets (Overview)