The magnetic permeability of a substance is defined as \\\\(\\mu=\\dfrac{B}{H}\\\\)where \\\\(B\\\\) is the established magnetic field inside the material,\\\\(H\\\\) is the applied external magnetic field.When the external applied magnetic field \\\\(H\\\\) is increased, the established magnetic field for a ferromagnetic material remains the same. Thus the magnetic permeability decreases.