Charge Distribution on Conducting Spheres 5B30.20


The two conducting spheres, the Faraday cage, the electrometer, and the 1000V power supply (if needed) are in the ElectrostaticsCabinet, B1.

The fur and proof plane are in the ElectrostaticsCabinet, A1.

Connect the Faraday cage to the electrometer, grounding the outside cage.

Set the electrometer to center zero, and 30V scale.

Connect one of the conducting spheres to ground. Move the other far away.

Discharge the proof plane.

Verify the proof plane is uncharged by brining it near the inner Faraday cage, and seeing that the needle does not deflect.


Here is the experiment:

There are many variations of this experiment that can be done.


On damp days, use the 1000V power supply rather than the fur to charge the second sphere.

If the inner Faraday cage retains a charge, discharge it by shorting it to the outer cage. Try doing this using a. your finger; or b. a wire with clip leads on both ends. Use whichever method leaves the needle closer to zero after you move your hand away from the inner cage.

Keep both spheres as far as practical from the Faraday cage and electrometer.

Make sure the leads to the electrometer are twisted.

Electric Fields and Potential



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