MMF = ΦR
R = MMF/ Φ
R is proportional to the reciprocal of the inductance.
The reluctance of a uniform gap, without leakage, is, therefore:
Calculation of the electrical resistance of a wire or bar of uniform cross-section:
whereσ is the wire material conductivity, l the length and A is the wire cross-sectional area.
Req. = R1 + R2 + R3 +…
Reluctances in Series: The combination of reluctances in series, with a common flux-path, results in:
Reluctances in Parallel: Flux in a magnetic circuit may flow in various leakage paths, as well as the useful one. It can be shown, by considering two parallel flux-paths, with flux driven by the same mmf, that the equivalent reluctance for two reluctances in parallel is:
All the Best.