Electric Interaction between Two Identical Conducting Spheres in a Uniform Electric Field

An experimental apparatus is devised to measure the interaction between two spheres separated by a small gap in a uniform electric field. The results show that the interaction between two conducting spheres is near that between two dielectric spheres with high permittivity. Accordingly, the calculation can be simplified by mirror image method, for it is only available for conducting system. A method using multiple mirror images of point charges is put forward to analyze the induction of two identical conducting spheres in a uniform electric field. The key operation on how to add compensative charges is emphasized and given out in detail. The results from experiment and calculation are compared, and they agree with each other very well.