Electric flux is a concept in electromagnetism that describes the flow of electric field lines through a surface. It is a measure of the electric field’s effect on that surface. The electric flux (Φ�ΦE) through a given surface is defined as the product of the electric field (�E) and the component of the surface area (�A) perpendicular to the field. Mathematically, it is expressed as:
Φ�=�⋅�⋅cos(�)ΦE=E⋅A⋅cos(θ)
where:
- Φ�ΦE is the electric flux,
- �E is the electric field vector,
- �A is the vector representing the surface area,
- �θ is the angle between the electric field vector and the surface normal.
In simpler terms, the electric flux is a measure of how much electric field penetrates or intersects a given surface. The cosine of the angle accounts for the fact that only the component of the electric field perpendicular to the surface contributes to the flux.
The unit of electric flux in the International System of Units (SI) is the volt-meter (V·m), which is equivalent to a newton·meter squared per coulomb (N·m²/C). The electric flux is a useful concept in understanding electric field interactions with surfaces and is commonly used in Gauss’s Law, which relates the electric flux through a closed surface to the enclosed electric charge.