Magnetic flux, usually denoted by
Greek letter Φ, is a measure of quantity of
magnetism, taking account of the strength and the extent of a
magnetic field. The
flux through an element of
area perpendicular to the direction of magnetic field is given by the product of the
magnetic field density[?] and the
area element. More generally, magnetic flux is defined by a
scalar product of the
magnetic field density[?] and the area element vector. The
Maxwell's equations in the absence of
magnetic monopoles requires that the magnetic flux through a closed surface is zero. The
SI unit of magnetic flux is the
weber.