The expression that gives magnetic flux is:
- Φ = BA cosθ
where Φ is the magnetic flux, B is the magnetic field, A is the area of the surface, and θ is the angle between the magnetic field and the surface normal.
This expression tells us the amount of magnetic field that passes through a surface, and is measured in units of webers (Wb) or tesla meters squared (T m²). It is important in understanding the behavior of magnetic fields in various physical systems, including electric motors, generators, transformers, and many others.