(i) The equipotential surfaces are as shown in Fig.
![The equipotential surfaces](https://www.sarthaks.com/?qa=blob&qa_blobid=11998547746177563484)
(ii) Electric potential on the axial line of an electric dipole.
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.
![distance r from the mid-point of the dipole](https://www.sarthaks.com/?qa=blob&qa_blobid=2355962466084498033)
The electric potential of OP due to the dipole is given b
![The electric potential of OP due to the dipole](https://www.sarthaks.com/?qa=blob&qa_blobid=8228823570293269000)
For a short dipole: r >> a, so r2 - a2 ≃ r2
So V = \(\frac{1}{4\piɛ_o} \frac{p}{r^2}\)