The electric flux of a surface is maximum when the area vector is parallel to the direction of the electric field.
The electric flux is the total number of lines of force passing through a surface. Electric flux is proportional to the number of electric field lines going through a virtual surface.
- If the electric field is uniform, the electric flux passing through a surface of vector area S is ΦE = E.S = EScosθ
- Electric flux has SI units of volt metres (V m), or, equivalently, newton metres squared per coulomb (N m2 C−1)