Figure 3 - Magnetic induction - Flux (Ø)
When a ferromagnetic material is placed in the coil of
Figure 1, an additional magnetic field is induced in the
material as shown in Figure 3. This induced field is called
flux, from the Greek verb meaning to flow. The symbol
for flux is Ø.
The degree to which this induced field is concentrated is
known as magnetic induction or flux density per unit area
normal to the direction of the magnetic path and is
designated by the symbol B. In the cgs system, the magnetic
induction is measured in maxwells (or lines) per square
centimeter. One line per square centimeter equals one
gauss. In the SI system, magnetic induction is designated in
Telsa. One Telsa equals 10,000 gauss. The relationship
between B and H for a ferro-magnetic material can be illustrated
by its normal magnetization curve shown in Figure 4