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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 force when forming a magnetic field in a classical vacuum.
4 Mathematics and statistics. 5 Geography, geology and geophysics. ... is the dimensional frequency, ... (ratio of the permeability of a specific medium to free space)
for virtually any well-behaved function g of dimensionless argument φ, where ω is the angular frequency (in radians per second), and k = (k x, k y, k z) is the wave vector (in radians per meter). Although the function g can be and often is a monochromatic sine wave , it does not have to be sinusoidal, or even periodic.
In statistics, the frequency or absolute frequency of an event is the number of times the observation has occurred/been recorded in an experiment or study. [ 1 ] : 12–19 These frequencies are often depicted graphically or tabular form.
It is a measure of material permeability variation after demagnetization, given by a formula = (), where , are permeability values, and t 1, t 2 are time from demagnetization; usually determined for t 1 = 10 min, t 2 = 100 min; range from 2×10 −6 to 12×10 −6 for typical MnZn and NiZn ferrites;
where μ is the magnetic permeability, ε is the (real) electric permittivity and σ is the electrical conductivity of the material the wave is travelling through (corresponding to the imaginary component of the permittivity multiplied by omega). In the equation, j is the imaginary unit, and ω is the angular frequency of the wave.
In electromagnetism, permeance is the inverse of reluctance.In a magnetic circuit, permeance is a measure of the quantity of magnetic flux for a number of current-turns. A magnetic circuit almost acts as though the flux is conducted, therefore permeance is larger for large cross-sections of a material and smaller for smaller cross section lengths.
The SI unit for permeability is the square metre (m 2).A practical unit for permeability is the darcy (d), or more commonly the millidarcy (md) (1 d ≈ 10 −12 m 2). The name honors the French Engineer Henry Darcy who first described the flow of water through sand filters for potable water supply.