Charging and Discharging Capacitors 5C30.30


Parts for this demonstration are found in the Electrostatics Cabinet, A4

A 9V battery is used to charge a capacitor. The brightness of a light bulb tracks the flow of current. When a switch is thrown, the capacitor discharges through another light bulb.

The demonstration should be stored with the switch closed so that the battery is open-circuited and the capacitor is close-circuited through the light bulb.

Discussion: the time is takes a bulb to dim is the characteristic time (RC time) of the circuit in which it is placed.