Point charge

A body of almost no size is called a point body or discrete body i.e. a sphere of radius R → 0 is a point like body.  Both field & potential are not defined on a discrete charge, as r → 0 implies E & V → ∞. Outside the point charge field & potential are

Field of a point charge has following properties

1. radially outward if charge is positive & inwards if it is negative.

2. at finite distance around it, field is spherically symmetric & obeys inverse square law i.e. it is not uniform

3. at infinite distance from the it, field is zero

4. maxi. it the charge is placed in vacuum or air.