Vacuum magnetic permeability

Vacuum magnetic permeability 245 Vacuum permittivity 31 Variable field NMR relaxometry 406 Volclay 306, 308-9... 

The macroscopic property related to the molecular polarizability a is the dielectric constant e, defined by the ratio of the permittivity of the medium to the electric constant, cq. It is also related to the refractive index n n = y/e, assuming the vacuum magnetic permeability to be equal to 1). The quantity measured in a dielectric constant experiment is... 

The tendency of the magnetic lines of force to pass through a medium relative to their tendency to pass through a vacuum is the magnetic permeability, p. This is one of the parameters that distinguishes a diamagnetic material from a paramagnetic substance. Permeability is defined as. 

Thus there is a direct analogy with Maxwell s equations in a medium with playing the role of the electric and magnetic permeability. Considering h= 1, one has the same permeability as the classical vacuum. Now for the metric perturbation as considered above, the modified Maxwell equations can be written as... 

Ho Magnetic permeability of vacuum (artificial) 47I-1CT7 1.2566370614 x 10 6N A 2 (use this for SI unit conversions otherwise, pure number also HnrC1)... 

In practice k and p are assumed to be unity in vacuum they are then dimensionless and are called the dielectric constant and magnetic permeability, respectively, of the medium. Since k and p cannot both be unity for the same medium, it is evident that the units based on the assumption that k is unity must be different from those obtained by taking p as unity. The former are known as electrostatic (e.s.) and the latter as electromagnetic (e.m.) units, and according to the facts recorded above... 

Above, So is the electric permittivity of vacuum and, similarly, is the magnetic permeability of vacuum. 

The magnetic permeability, [x, is the ratio of the flux [ix, number of lines of force per unit cross section) in the substance to that in a vacuum. The ratio is greater than unity for a paramagnetic substance and less, but not much less, than unity for a diamagnetic one (Fig. 32). 

Because both B and / will tend to be proportional to an external field, dividing Eq. 11.32 by // yields ratios (//// and BlH ) that will be essentially constant for a given substance. The term called the magnetic permeability, is a ratio of the density of the magnetic force lines in the presence of the sample to the same density with no sample for a vacuum this ratio will be equal to I. The term I/H is the magnetic susceptibility per unit volume (k), which expresses the degree to which a material is subject to magnetization ... 

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