19)
that is, it is a vector whose magnitude is charge q times the separation
2a (between the pair of charges q, –q) and the direction is along the line
from –q to q 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