The electrostatic potential at a point with position vector r due to a
point dipole of dipole moment p placed at the origin is
ˆ2
1
( )
=4 ε
π
p r
r
o
V
r
The result is true also for a dipole (with charges –q and q separated by
2a)  for r >> a 4 For a charge configuration q1, q2,