Answer to Question #123338 in Electricity and Magnetism for Ujjal Bhattacharjee

Question

A charge _q is distributed uniformly over a sphere with a positive charge q at its centre.Also the same situation for an ellipsoid ..with respect to the origin of the coordinate system find the correct statement
(a)dipole moment is zero for both cases (b)dipole moment non zero for 1st case but zero in next case (c)dipole moment zero for 1st case but non zero in next case (d ) non zero both cases

Answer 1

In the case of the sphere the effective charge also situated at its center.

Answer: (c)dipole moment zero for 1st case but non zero in next case