Microscopic Origins of Reluctance
The reluctance of a magnetically uniform magnetic circuit element can be calculated as:
where
- l is the length of the element in metres
- is the permeability of the material ( is the relative permeability of the material (dimensionless), and is the permeability of free space)
- A is the cross-sectional area of the circuit in square metres
This is similar to the equation for electrical resistance in materials, with permeability being analogous to conductivity; the reciprocal of the permeability is known as magnetic reluctivity and is analogous to resistivity. Longer, thinner geometries with low permeabilities lead to higher reluctance. Low reluctance, like low resistance in electric circuits, is generally preferred.
Read more about this topic: Magnetic Circuit
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