# relative permeability

## Definition

### Electronics

- The ratio of the permeability of a given material or medium, to the permeability of free space. It is obtained using the following formula: μ
_{r}, = μ/μ_{0}, where μ_{r}, is relative permeability, μ is the permeability of a given material or medium, and μ_{0} is the permeability of free space. According to this formula, the relative permeability of free __space__ is 1. Materials whose relative permeability is less than 1 are diamagnetic, those slightly above 1 are paramagnetic, and those substantially above 1 are __ferromagnetic__.

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