Series and parallel light bulbs.
A board is made which allows one to switch light bulbs in and out of the circuit. Similar or different size light bulbs may be switched in and out to give several combinations. The brightness of the bulbs indicates how the currents are flowing for different series and parallel combinations of resistance.
|Series and parallel circuit board||021-11A|
|different wattage bulbs||021-16B|
|DC power supply|