Electric Flux
Electric field lines used to describe the basic nature of the electric field in two dimensional forms. What if we want to describe electric field in a three-dimensional form, this can be done with the help of electric flux. It is the measure of flow of the electric field through a given area. It is proportional to the number of electric field lines going through a normally perpendicular surface.
What is Electric Flux?
Electric flux is defined as a number of electric filed lines, passing per unit area. It is a physical quantity to measure the strength of electric filed and frame the basics of electrostatics. It is also defined as the product of electric field and surface area projected in a direction perpendicular to the electric field.

Mathematically, φE = E.A
When the same plane is tilted at an angle θ, the projected area is given as A cosθ and the total flux through this surface is:
Electric Flux (φE) = E.A cos θ; Where,
E = Magnitude of the Electric Field,
A = surface area,
θ = Angle made by the plane and the axis parallel to the direction of flow of the electric field.
Applications of Electric Flux:
Electric flux forms the basic foundations of electrostatics and it has application like:
- Electric flux simplifies evaluation of electric field in complex figures.
- Electric flux helps in calculation of electric field.