Deduce an expression for the electric potential due to an electric dipole at any point on its axis. Mention one contrasting feature of electric potential of a dipole at a point as compared to that due to a single charge.
Let P point at distance r from the centre of the dipole.
Electric potential at point P will be
For a far away point,
At large distances, dipole potential falls off as 1/r², whereas the potential due to a single charge falls off as 1/r.