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The relative static permittivity of a solvent is a relative measure of its chemical polarity. For example, water is very polar, and has a relative static permittivity of 80.10 at 20 °C while n-hexane is non-polar, and has a relative static permittivity of 1.89 at 20 °C. [26]
By definition, a perfect vacuum has a relative permittivity of exactly 1 whereas at standard temperature and pressure, air has a relative permittivity of ε r air ≡ κ air ≈ 1.0006 . Relative permittivity is directly related to electric susceptibility (χ) by = otherwise written as
Relative permittivity = electrostatics (ratio of capacitance of test capacitor with dielectric material versus vacuum) Specific gravity: SG (same as Relative density) Stefan number: Ste = Josef Stefan
If a dielectric material is a linear dielectric, then electric susceptibility is defined as the constant of proportionality (which may be a tensor) relating an electric field E to the induced dielectric polarization density P such that [3] [4] =, where
In electromagnetism, the Clausius–Mossotti relation, named for O. F. Mossotti and Rudolf Clausius, expresses the dielectric constant (relative permittivity, ε r) of a material in terms of the atomic polarizability, α, of the material's constituent atoms and/or molecules, or a homogeneous mixture thereof.
The internal component of a round wire's inductance vs. the ratio of skin depth to radius. That component of the self inductance is reduced below μ/8 π as skin depth becomes small (as frequency increases). The ratio AC resistance to DC resistance of a round wire versus the ratio of the wire's radius to the skin depth.
The effective temperature coefficient varies with temperature and purity level of the material. The 20 °C value is only an approximation when used at other temperatures. For example, the coefficient becomes lower at higher temperatures for copper, and the value 0.00427 is commonly specified at 0 °C. [53]
(The real part of the permittivity is the normal effect of capacitance and results in non-dissipative reactive power.) If the conductivity σ of the material is small, or the frequency is high, such that σ ≪ ωε (with ε = ε r ″ · ε 0 ), then Joule heating is low, and dielectric heating is the dominant mechanism of loss of energy from ...