- Electric potential is the amount of work done by an external force in moving a unit positive charge from one point to another in electrostatic field.
Its SI unit : JC-1, Volt, NmC-1.
- Electric potential due to a point source charge q at a distance r from it
- The potential per unit distance is called potential gradient. It can be expressed as dV/dr. The relation between electric field and potential gradient :
- Electric potential due to a dipole at a point at distance r and making an angle 0 with the dipole moment p is given by
- Electric potential on the axial line.
- Electric potential on the equatorial line
- Electric potential for an isolated conducting charged sphere of radius R carrying charge Q'
(a) The electric potential at the surface of the sphere and at every point inside the sphere is
(b) The electric potential at points outside the sphere is
where r > R is the distance of the point from the centre of the sphere.
- Electric field E is always perpendicular to equipotential surfaces.
