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In electrostatics, a perfect conductor is an idealized model for real conducting materials. The defining property of a perfect conductor is that static electric field and the charge density both vanish in its interior. If the conductor has excess charge, it accumulates as an infinitesimally thin layer of surface charge. An external electric ...
Another common term encountered for both absolute and relative permittivity is the dielectric constant which has been deprecated in physics and engineering [2] as well as in chemistry. [ 3 ] By definition, a perfect vacuum has a relative permittivity of exactly 1 whereas at standard temperature and pressure , air has a relative permittivity of ...
where λ is the wavelength, c is the speed of light in vacuum and κ = μ 0 c / 2π = 59.95849 Ω ≈ 60.0 Ω is a newly introduced constant (units ohms, or reciprocal siemens, such that σλκ = ε r remains unitless).
The number density of the electron gas was assumed to be =, where Z is the effective number of de-localized electrons per ion, for which Drude used the valence number, A is the atomic mass per mole, [Ashcroft & Mermin 10] is the mass density (mass per unit volume) [Ashcroft & Mermin 10] of the "ions", and N A is the Avogadro constant.
Optical conductivity is the property of a material which gives the relationship between the induced current density in the material and the magnitude of the inducing electric field for arbitrary frequencies. [1]
Informally, Alfvén's theorem refers to the fundamental result in ideal magnetohydrodynamic theory that electrically conducting fluids and the magnetic fields within are constrained to move together in the limit of large magnetic Reynolds numbers (R m)—such as when the fluid is a perfect conductor or when velocity and length scales are infinitely large.
The electric field is perpendicular, locally, to the equipotential surface of the conductor, and zero inside; its flux πa 2 ·E, by Gauss's law equals πa 2 ·σ/ε 0. Thus, σ = ε 0 E. In problems involving conductors set at known potentials, the potential away from them is obtained by solving Laplace's equation, either analytically or ...
The density of the linear momentum of the electromagnetic field is S/c 2 where S is the magnitude of the Poynting vector and c is the speed of light in free space. The radiation pressure exerted by an electromagnetic wave on the surface of a target is given by P r a d = S c . {\displaystyle P_{\mathrm {rad} }={\frac {\langle S\rangle }{\mathrm ...