Magnetic Permeability

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Related to Magnetic Permeability: Electric permittivity

magnetic permeability

[mag′ned·ik ‚pər·mē·ə′bil·əd·ē]
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Magnetic Permeability


a physical quantity that characterizes the relationship between the magnetic induction B and the magnetic field H in a substance. Its designation is JUL; for isotropic substances μ = B/H (in the cgs system of units), or μ = B/μoH (in the International System of Units; μ0 is the magnetic constant).

For anisotropic solids (crystals) the magnetic permeability is a tensor. It is related to the magnetic susceptibility K by the formula μ = 1 + 4πK (in the cgs system of units), or μ = 1 + K (in the International System of Units), where μ is measured in dimensionless units. For a physical vacuum K = 0 and μ = 1.

For diamagnetic materials K < 0 and μ < 1; for paramagnets and ferromagnets K > 0 and ju > 1. Magnetic permeability is called static or dynamic, respectively, depending on whether μ for ferromagnetic materials is measured in a constant or variable magnetic field. The values of the two types of permeability do not agree, since eddy currents, magnetic viscosity, and resonance phenomena affect the magnetization of ferromagnets in a variable magnetic field. Magnetic permeability is a complicated function of H, and the concepts of differential, initial, and maximum magnetic permeabilityhave been introduced to describe the relationship.


Vonsovskii, S. V. Magnetizm. Moscow, 1971.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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