ABSTRACT
The resulting magnetic induction B produced by an external source of magnetic field H (such as moving charge or an electric current) depends upon the “ease” with which the surrounding material permits the creation of magnetic field lines. This is the permeability of the medium. For free space, the permeability is µo = 4π × 10−7 Wb A−1 m−1
In free space the source of B is the applied field intensity H. When the space is occupied by a magnetic material, the field B now present is higher due to the extra contribution of magnetization from the material. The total permeability is µ. The ratio µ / µ o is the relative permeability µr.
