Electrical Engineering ⇒ Topic : Concept of relative permeability.

Concept of relative permeability. The relative permeability of a material is a measure of the relative ease with which that material conducts magnetic flux compared with the conduction of flux in air. Fig.(a) illustrates the concept of relative permeability. In Fig.(a) (i), the magnetic flux passes between the poles of a magnet in air. Consider a soft iron ring (II, = 8,000) placed between the same poles as shown in Fig. (a) (ii). Since soft iron is a very good conductor of magnetic flux, the flux follows a path entirely within the soft iron itself. The flux density in the soft iron is much greater than it is in air. In fact, flux density in soft iron will be 8,000 times (i.e. μ_r times) the flux density in air.

                                                                                        figure (a)

Due to high relative permeability of magnetic materials (e.g. iron, steel and other magnetic alloys), they are widely used for the cores of all electromagnetic equipment.