Physics Demonstrations at Cal Poly Pomona
Demo Index:
Pira Index:
Title:
Description:
Demonstrates that positive ions in the plasma are attracted to the negative plate.
Equipment:
1. Wimshurst machine
2. Modified sliding capacitor
3. Candle with PVC holder & matches
4. 2 copper rods
5. Plexiglas box (or 2 stacks of licorice containers)
Procedure:
1. Set up as shown w/ discharge arms separated & copper wires hooked to each of them and to attachment screws on the sliding capacitor.
2. Light candle.
3. Charge up the device by cranking (has to be turned relatively fast to build a charge).
4. Since the gases producing the candle flame are ionized (having lost electrons) the positively charged gases of the flame will be attracted by the negative plate.
Caution: to discharge the Wimshurst, carefully swing the discharge arms to the middle of the apparatus until they touch.
