A small sphere of radius `r_1` and charge `q_1` is enclosed by a spherical shell of radius `r_2` and charge `q_2`. Show that if `q_1` is positive, charge will necessarily flow from the sphere to the shell (when the two are connected by a wire) no matter what the charge `q_2,` on the shell is.

Explanation

The potential inside the shell is constant and is equal to that on its surface. The potential difference then depends only on `q_1`. Potential is highest on A. Hence charge flows from A to E irrespective of the value of `q_2`.