Reference: EM23
Category: Electromagnetism
Purpose: Shows the distribution of charge on concentric shells.
Description: Use the copper sphere on an insulating stand and the two brass hemispheres that fit over it closely. Charge the sphere by flicking it with flannel (or by rubbing it with rabbit skin). Fit the hemispheres over it and then pull them of simultaneously. It can be shown by touching the sphere against the plate of an electroscope that it has lost all its charge and that the hemispheres have taken up the charge. This experiment is difficult to pull off successfully because one hemisphere tends to come off before the other. The best way to achieve this is to get a student to hold the sphere firmly by its insulating support while you pull the hemispheres off.
