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The reciprocal of permeability is magnetic reluctivity. In SI units, permeability is measured in henries per meter (H/m), or equivalently in newtons per ampere squared (N/A 2). The permeability constant μ 0, also known as the magnetic constant or the permeability of free space, is the proportionality between magnetic induction and magnetizing ...
The vacuum magnetic permeability (variously vacuum permeability, permeability of free space, permeability of vacuum, magnetic constant) is the magnetic permeability in a classical vacuum. It is a physical constant , conventionally written as μ 0 (pronounced "mu nought" or "mu zero").
Alternatively in terms of magnetic permeability (analogous to electric conductivity): = where: μ, permeability of material, A, cross-sectional area, ℓ, magnetic path length. The SI unit of magnetic permeance is the henry (H), equivalently, webers per ampere. [a]
Symbol [1] Name of quantity Unit name Symbol Base units E energy: joule: J = C⋅V = W⋅s kg⋅m 2 ⋅s −2: Q electric charge: coulomb: C A⋅s I electric current: ampere
Cassette tape label with coercivity (a measure of the external magnetic flux required to magnetize the tape) measured in oersteds. The oersted is defined as a dyne per unit pole. [clarification needed] [6] The oersted is 1000 / 4π (≈79.5775) amperes per meter, in terms of SI units. [7] [8] [9] [10]
Using SI units, the magnetic induction B is related to H by the relationship = (+) = (+) =, where μ 0 is the vacuum permeability (see table of physical constants), and (1 + χ v) is the relative permeability of the material.
In the Gaussian system, unlike the ISQ, the electric field E G and the magnetic field B G have the same dimension. This amounts to a factor of c between how B is defined in the two unit systems, on top of the other differences. [3] (The same factor applies to other magnetic quantities such as the magnetic field, H, and magnetization, M.)
The units of the first two quantities are the ampere and the ampere per centimetre respectively. The unit of magnetic permeability is that of the emu system, and the magnetic constitutive equations are B = (4 π /10)μH and B = (4 π /10)μ 0 H + μ 0 M. Magnetic reluctance is given a hybrid unit to ensure the validity of Ohm's law for magnetic ...