Kirchhoff's circuit laws and electrical power = Vi can be demonstrated with the light bulb board. The circuit is displayed to the class's view and voltages and currents can be measured in various places in the circuit.

A very interesting demonstration is to show a 100 watt bulb and a 60 watt bulb in parallel (as in an ordinary house circuit), and then to try the two bulbs in series (the 60 watt bulb is then brighter).

This board does not obey Ohm's law, however, since the resistance of the filaments depends on temperature, and therefore on voltage (or current). But you can demonstrate resistors in series and parallel by putting three 100 watt bulbs (or three 100 ohm resistors) in series and parallel and measure the resistance of the combinations with an ohmmeter.

A more compact version of the parallel and series light bulbs is available that uses a 12V car battery. All the light bulbs are 2.8W and can be hooked up in various configurations. The voltage and amps can be measured simultaneously using two digital multimeters.