A point dipole with an electric moment `p` is located at a distance `l` from an infinite conducting plane. Find the modulus of the vector of the force acting on the dipoel if the vector `p` is perpendicular to the plane.

Explanation

Using the concept of electrical image, force on the dipole `vec(p)`,
`vec(F) = p (del vec(E))/(del l)`, when `vec(E)` is field at the location of `vec(p)` due to `(-vec(p))`
or, `|vec(f)| = |(del vec(E))/(del l)| p = (3 p^(2))/(32 pi epsilon_(0) l^(4))`
as, `|vec(E)| = (p)/(4pi epsilon_(0) (2l)^(3))`