Electric Field due to a Discrete Distribution of Charge(Principle of Superposition)--

It states that electric field at any point due to a group of charges is equal to the vector sum of the electric fields produced by each charge individually at that point, when all oter charges are assumed to be absent.

Let us consider that n point charges q₁, q₂, q₃……..are distributed in space in discrete manner.

The net electric field at point P will be,

Electric Dipole

When two equal and opposite charges are placed at a small distance, the combination is called a electric Dipole.

The strength of dipole is measured by Dipole Moment, a vector quantity, whose magnitude is equal to product of either charge and distance between the two charges and has the direction along the negative to positive charge.

Electric Field due to a Circular Ring of Charge—

Let us consider a circular ring of radius ‘a’ and total charge q is distributed over it.

            Let P be a point at a distance r from the centre of the ring and at the axis of ring, where electric field due to ring is to be determined.

Electric Field—

The electric field due to a charge is the space around the charge in which it exerts an electrostatic force on any other charge.

Electric Field Intensity—

The electric field intensity at a point due to a source charge may be defined as the force experienced per unit positive test charge placed at that point without disturbing the source charge.