Question

Derive an expression for electric potential for a sytem of point chargesw

Answer 1

,Electric Field on Axial Line of an Electric DipoleLet P be at distance r from the centre of thedipole on the side of charge q. Then,Where, is the unit vector along the dipole axis (from − q to q). Also,The total field at P isFor r >> aElectric Field for Points on the Equatorial PlaneThe magnitudes of the electric field due to the two charges +q and −q are given by,The directions of E+q and E−q are as shown in the figure. The components normal to the dipole axis cancel away. The components along the dipole axis add up.∴ Total electric field[Negative sign shows that field is opposite to]At large distances (r >> a), this reduces toHere is a link given below which will also help you to get the answer of this questions with proper explanation .