Question

3. Two identical spheres, A and B, made out of non-conducting (i.e. insulating) materials are given identical charges, +q, uniformly distributed over their surfaces. They are placed so that their centers are separated by some distance, r. This distance is not much greater than the radius of the spheres.

Two other identical spheres, C and D, are made out of metal. They are the same size as spheres A and B. They are also each given a charge, +q, and placed a distance, r, away from each other. In other words the setup of C and D is identical to the setup of A and B, except for the material that the spheres are made of.

Compare the forces that A and B exert on each other with the forces that C and D exert on each other. If they are different, explain why they are different and which is larger. If they are the same, explain why they are the same.

Answer 1

When spheres are charged with positive charge then the magnitude of the electric force between the two non-conducting spheres (A and B) is greater than the pair which consists of two conducting spheres (C and D)