For electric on the axial line,
Let an electric dipole consist of two charges -q and +q separated by a distance 2a as shown in the figure. Let us find electric potential at point P, at a distance r from the mid-point of the dipole.
![electric potential of dipole](https://www.sarthaks.com/?qa=blob&qa_blobid=7878956481643898772)
The electric potential of OP due to the dipole is given by
![The electric potential of OP due to the dipole](https://www.sarthaks.com/?qa=blob&qa_blobid=11091967041890230204)
For a short dipole: r >> a, so r2 - a2 ≃ r2
So V = \(\frac{1}{4\piɛ_o} \frac{p}{r^2}\)
So for a dipole
V ∝ \(\frac{1}{r^2}\)
And for a monopole (or a single charge)
V ∝ \(\frac{1}{r}\).