What is relative magnetic permeability of superconductors?

What is magnetic permeability ?

What is the relative permeability of air ?

What is the relative permeability of air ?

What is the unit of magnetic permeability?

What are units of magnetic permeability?

If mu_(0) is absolute permeability of vacum and mu_(r) is relative magnetic permeability of another medium , then permeability mu of the medium