In terms of p, the electric field of a dipole at large distances
takes simple forms:
At a point on the dipole axis
E
p
=
42
πεor3
(r >> a)
(1 20)
At a point on the equatorial plane
E
= − 4p
πεor3
(r >> a)
(1 21)
FIGURE 1 17 Electric field of a dipole
at (a) a point on the axis, (b) a point
on the equatorial plane of the dipole