Charge in a Capacitor
This demonstration illustrate how the capacitance value determines the amount of charge a capacitor can hold, for a given voltage. In this demo, we use a PASCO variable capacitor --basically two circular aluminum plates facing each other, whose separation distance can be varied. One plate is connected to a good ground, while the other is connected to an electroscope. Starting with the plates a few centimeters apart, charge the plate until the electroscope shows evidence of the charge. Then simply vary the distance between the plates and observe how charge flows from the capacitor to the electroscope as the capacitance is reduced and flows back to the capacitor as you increase the capacitance.
| Qty. |
name |
location |
notes |
| 1 |
PASCO variable capacitor |
W106; North Shelves; U2-L3 |
|
| 1 |
Electroscope |
W106; North Shelves; U2-L2 |
|
| 3 |
alligator clips |
W106; East Wall; top of metallic drawers |
for connections |
| 2 |
18-in banana cables |
W104; West Wall |
|
| 1 |
3-prong Extension cord |
W106; North Drawers; U2 |
to get to the ground line. |
