2 Potential at a point is the work done per unit charge (by an external
agency) in bringing a charge from infinity to that point Potential at a
point is arbitrary to within an additive constant, since it is the potential
difference between two points which is physically significant If potential
at infinity is chosen to be zero; potential at a point with position vector
r due to a point charge Q placed at the origin is given is given by
1
( )
4
o
Q
V
r
ε
=
π
r
3