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Flux and flux density

Around a magnet there is a magnetic field and this gives a ‘flow of magnetic energy’ around the magnet. It is this flow of energy that we call magnetic flux (F).
Magnetic flux is given the symbol F and is measured in Webers (Wb).

In position B there are a smaller number of magnetic field lines passing through the loop than in position A. We call the amount of flux passing through a unit area at right angles to the magnetic field lines the flux density (B) at that point.

Flux density is measured in Tesla (T) where 1 T = 1 Wbm-2
Flux (F) = Flux density (B) x area through which flux passes (A)

Flux F = BA
Flux linkage = NF = NBA
© Keith Gibbs 2008