Gauss Theorem—

It states that the total electric flux through a closed surface enclosing a charge is equal to 1/ε₀ times the magnitude of the charge enclosed.

• Let a point charge q is placed at the centre of a sphere of radius r. let E be the electric field at any point P on the surface of sphere. Then,`                                                    

Let  be the small area vector element around the point P. then, the electric flux through the small area element