Parallel Plate Capacitors

Return to Capacitance

Description:

Large (20 cm.) plates mounted to allow any separation distance from 1 to 120 mm. (includes scale). Capacitance from 2.3 to 280 pF. The capacitor is connected to an Electrometer measuring the potential difference across the plates. Connect the (-) ground lead from the Electrometer to the movable plate for best results. Charge the capacitor with a 9V battery. Slowly separating the plates decreases the capacitance and therefore the voltage measured by the Electrometer will increase. This shows that the work done by separating the charged plates increase the Potential. A piece of plexiglass can be used to demonstrate a dielectric, however, it is very hard for the dielectric not to be charged. Putting an insulator between the plates has unpredictable results, but shows the concept of adding a dielectric.

Location:

• Capacitor: Shelf I-2
• 9 volt Battery: Drawer 69
• Electrometer: Shelf K-2