An electric dipole consists of a positive charge q and a negative charge -q. The distance between these two charges is a. Show that at distances r very far from the dipole (that is, r > a), the electric field falls as 1/r rather than 1/r2. Note that you may have to use the binomial expansion (1+x)" - 1 + nx + .. for small x.

An electric dipole consists of a positive charge q and a negative charge -q. The distance between these two charges is a. Show that at distances r very far from the dipole (that is, r > a), the electric field falls as 1/r rather than 1/r2. Note that you may have to use the binomial expansion (1+x)" - 1 + nx + .. for small x.