From Eqs. ( . ) and ( . ) we obtain, ( µ χ B H ( .
) = µ µ r H = µ H ( . ) where µ r = + χ , is a dimensionless quantity called the relative magnetic permeability of the substance. It is the analog of the dielectric constant in electrostatics. The magnetic permeability of the substance is µ and it has the same dimensions and units as µ ; µ = µ µ r = µ ( + χ ).
The three quantities χ , µ r and µ are interrelated and only one of them is independent. Given one, the other two may be easily determined.