Electric field on the axial line of electric dipole.

Let us consider an electric dipole of length “2l”. Negative charge (–q) is placed at “A”. Positive charge (+q) is placed at “B”. Axial line is a st. line which passes through both –ve charge + ve charge.
We want to calculate electric field on axial line of electric dipole at point “P”. Which is “r” distance away from the mid-point of the electric dipole.
vector (E1) is the electric field due to (–ve) charge which is acting inward. vector E2 is the electric field due to (+ve) charge which is acting outward.



Eqn. (10) is the general eqn. for electric field on the axial line of electric dipole.