Static charges lie only on an outside surface of a charged object and this device dramatically demonstrates it. Charge the sphere by touching it to the dome of a Van de Graaf generator. When a proof plane is touched to the outer surface, a charge will be acquired, but when it is touched to the inside surface, no charge will be transferred. The sphere's large re-entrant hole (4 cm) makes these transfers easy and consistent.
Additional ResourcesNo Additional Resources at the time.
Flinn Catalog/Reference Manual Page 679