Question

derive an expression for the electric field at a point on the axial line of electric dipole ​

Answer 1

Let two charges +q and –q of equal magnitude be placed at a distance of 2d thus forming an electric dipole between them. Let P be a point along the axial line of the dipole at a distance r from the midpoint of the dipole. ... As the charge is positive, the electric field will be acting outward to the charge +q.