Twin adhering conducting spheres in an electric field-an alternative geometry for an electrostatic voltmeter

Abstract

An equivalent image system is found for the effect of a uniform electric field on a conductor formed from two similar spheres in contact, and the induced dipole moment and principal polarizabilities are calculated. These results are applied to the oscillation of the conductor in an electric field with a view to replacing the ellipsoid used in the ellipsoidal electrostatic voltmeter. The twin-sphere conductor has advantages of ease of precise construction and measurement compared with an ellipsoid. An experimental comparison is made between an ellipsoidal and a twin sphere conductor.