Magnetic flux is a concept in physics that describes the amount of magnetic field passing through a given area. It's a measure of the total magnetic field lines that penetrate a surface or loop. Mathematically, magnetic flux (
Φ
Φ) is defined as the product of the magnetic field (
B) and the area (
A) through which the field lines pass, multiplied by the cosine of the angle (
θ) between the magnetic field and the normal to the area:
Φ
=
⋅
⋅
cos
(
)
Φ=B⋅A⋅cos(θ)
Where:
Φ
Φ is the magnetic flux
B is the magnetic field strength
A is the area
θ is the angle between the magnetic field and the normal to the area.
In simpler terms, magnetic flux represents the number of magnetic field lines that go through a specific surface area. If the magnetic field is perpendicular to the surface (angle
θ is 0), then the maximum magnetic flux passes through. If the field lines are at an angle to the surface, the effective magnetic flux is reduced.
Magnetic flux is measured in units of Weber (Wb) in the International System of Units (SI). It's an important concept in understanding electromagnetic induction, where changes in magnetic flux through a circuit can induce an electromotive force (EMF) or voltage in that circuit, according to Faraday's law of electromagnetic induction.