Magnetic inductance

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Magnetic inductance is not to be confused with "Magnetic induction", which usually refers to Magnetic field.

In a magnetic circuit, magnetic inductance (inductive magnetic reactance) is the analogy to inductance in an electrical circuit. Magnetic inductance is a concept in the gyrator-capacitor model for magnetic systems.In the SI system, it is measured in units of -Ω−1. This model makes magnetomotive force (mmf) the analog of electromotive force in electrical circuits, and time rate of change of magnetic flux the analog of electric current. The gyrator-capacitor model is a lumped-element model for analysis of magnetic fields.

For phasor analysis the magnetic inductive reactance is:


is the magnetic inductivity (SI Unit: -s·Ω−1)
is the angular frequency of the magnetic circuit

In the complex form it is a positive imaginary number:

The magnetic potential energy sustained by magnetic inductivity varies with the frequency of oscillations in electric fields. The average power in a given period is equal to zero. Due to its dependence on frequency, magnetic inductance is mainly observable in magnetic circuits which operate at VHF and/or UHF frequencies.

The notion of magnetic inductivity is employed in analysis and computation of circuit behavior in the gyrator-capacitor model in a way analogous to inductance in electrical circuits.

See also[edit]


  1. Pohl R. W. ELEKTRIZITÄTSLEHRE. – Berlin-Göttingen-Heidelberg: SPRINGER-VERLAG, 1960.
  2. Popov V. P. The Principles of Theory of Circuits. – M.: Higher School, 1985, 496 p. (In Russian).