Magnetic permeability is given by the formula

Where

B=magnetic field

H=magnetization intensity

SI Unit of magnetic field B is N/Am

Its dimensional formula is

SI unit of magnetization intensity is A/m

Its dimensional formula is

Therefore, dimensional formula of permeability μ =

Whereas relative permeability is given as the ratio of magnetic permeabilty of any medium to the permeability of the vacuum

Where μ₀=absolute permeability of vacuum

So relative permeability is a dimensionless quantity

Therefore, relative permeability is dimensionless quantity a permeability have different dimensions