BCIT Physics Department

Demonstration Manual

Electricity and Magnetism

DEM79 - Electrostatic Ping Pong


- to demonstrate attractive and repulsive electrostatic forces.



Connect the DEM79 apparatus to the Wimshurst machine. While cranking the machine swing the conducting sphere such that the sphere touches one of the charged plates. The sphere will become "like" charged, be repelled, and swing across the gap to hit the opposite plate.

Charge transfer again takes place and the sphere swings back to the first plate and so on. The sphere will continue the back and forth oscillation for as long as one provides "fresh" charge via cranking the Wimshurst machine.

After the cranking has stopped there is sufficient capacitance to allow oscillation to occur for a number of additonal swings.

youtube logo   Watch an Capacitor Charge Demo: Oscillating Ball video demonstration on Youtube

- Video Created at Utah State University by Professor Boyd F. Edwards and assistants.