
Flux density
Encyclopedia
Formal Statement
The flux density is simply defined as the amount of flux passing through a unit-area.Mathematical Statement
The flux density would essentially be the number of field lines passing through a defined unit-area.



The Flux density is precisely equal to the flux through an area. If we take a


or in the general terms for flux:

where:
is a vector field
Vector fieldIn vector calculus, a vector field is an assignmentof a vector to each point in a subset of Euclidean space. A vector field in the plane for instance can be visualized as an arrow, with a given magnitude and direction, attached to each point in the plane...is the vector area of the surface S, directed as the surface normal
Surface normalA surface normal, or simply normal, to a flat surface is a vector that is perpendicular to that surface. A normal to a non-flat surface at a point P on the surface is a vector perpendicular to the tangent plane to that surface at P. The word "normal" is also used as an adjective: a line normal to a...
,is the resulting flux.
Bearing in mind that:
- If and only if
is the same for both quantities.