magnetic flux (symbol Φ) Measure in webers (Wb) of the strength and extent of a magnetic field. The flux through an area A at right angles to a uniform magnetic field is Φ = μHA, where μ is the magnetic permeability of the medium and H is the magnetic field intensity. Magnetic flux density, which is measured in teslas (T), is the flux per unit area (symbol B), which equals μH. Change of magnetic flux through a circuit induces an electromotive force.

magnetic flux The magnetic induction, perpendicular to the surface area of a nearby body, multiplied by the area of the body.