Permeability is the ability with which the magnetic material forces the magnetic flux through a given medium. Permeability is the magnetic property of the medium.
The flow of flux in a magnetic material is depend on both magnetic field strength and magnetic property or medium of the magnetic material.
There are two types of permeability.
1) absolute permeability
2) relative permeability
1) absolute permeability: absolute permeability is the ratio of magnetic flux density (B) to magnetic field strength (H) in a particular medium is called as absolute permeability.
Mathematically absolute permeability is given by,
Where, B is magnetic flux density.
H is magnetic field strength or magnetizing force.
μ is absolute permeability.
The unit of absolute permeability is heneries per metre (H/m)
2) relative permeability: relative permeability is the ratio of magnetic flux density (B) in a medium to magnetic flux density in free space (B0).
Mathematical relative permeability is given by,
The magnetic field strength (H) is same for both. Relative permeability is unitless it has no dimensions.