Electric Field

What Is an Electric Field?

An electric field is defined mathematically as a vector field that can be associated with each point in space, the force per unit charge exerted on a positive test charge at rest at that point.

The formula of the electric field is given as,

E = F /Q

Where,

E is the electric field. F is the force. Q is the charge.

The direction of the field is taken as the direction of the force which is exerted on the positive charge. The electric field is radially outwards from the positive charge and radially towards the negative point charge.

The electric field is generated by the electric charge or by time-varying magnetic fields. In the case of an atomic scale, the electric field is responsible for the attractive forces between the atomic nucleus and electrons which hold them together.

According to Coulomb’s law, a particle with electric charge q1 at position x1 exerts a force on a particle with charge q0 at position x0 of,

Where,

r1,0 is the unit vector in the direction from point x1 to point x0

ε0 is the electric constant, also known as absolute permittivity of free space C2m-2N-1

When the charges q0 and q1 have the same sign, the force is positive, and the direction is away from other charges, which means they repel each other. When the charges have unlike signs, the force is negative, and the particles attract each other.

The electric field is force per unit charge,

The electric field can be found easily by using Gauss’s law which states that the total electric flux out of a closed surface is equal to the charge enclosed divided by the permittivity.

Or total flux linked with a surface is 1/ ε0 times the charge enclosed by the closed surface.

The electric field can also be calculated by Coulomb’s law, but Gauss’s law is easier. Besides, Gauss’s law is just a replica of Coulomb’s law. If we apply Gauss’s theorem to a point charge enclosed by a sphere, we will arrive at Coulomb’s law.

Read More: Magnetic Fields