## Displacement current |

This article needs attention from an expert in Physics. (January 2018) |

Part of a series of articles about |

In **displacement current density** is the quantity ∂* D*/∂

The idea was conceived by

The

where:

*ε*is the_{0}permittivity of free space**E**is theelectric field intensity **P**is thepolarization of the medium

Differentiating this equation with respect to time defines the *displacement current density*, which therefore has two components in a ^{[1]}(see also the "displacement current" section of the article "

The first term on the right hand side is present in material media and in free space. It doesn't necessarily come from any actual movement of charge, but it does have an associated magnetic field, just as a current does due to charge motion. Some authors apply the name *displacement current* to the first term by itself.^{[2]}

The second term on the right hand side, called polarization current density, comes from the change in * P*. A changing state of polarization corresponds to charge movement and so is equivalent to a current, hence the term "polarization current".

Thus,

This polarization is the displacement current as it was originally conceived by Maxwell. Maxwell made no special treatment of the vacuum, treating it as a material medium. For Maxwell, the effect of * P* was simply to change the

The modern justification of displacement current is explained below.

In the case of a very simple dielectric material the

where the *ε = ε _{0} ε_{r}*,

*ε*is the relative permittivity of the dielectric and_{r}*ε*is the_{0}electric constant .

In this equation the use of *ε* accounts for
the polarization of the dielectric.

The

The forms in terms of *ε* are correct only for linear *ε* may be replaced by a

For a linear isotropic dielectric, the polarization * P* is given by:

where *χ _{e}* is known as the

Other Languages

العربية: تيار الإزاحة

অসমীয়া: সৰণ প্ৰৱাহ

বাংলা: সরণ প্রবাহ

català: Corrent de desplaçament

Deutsch: Verschiebungsstrom

eesti: Nihkevool

Ελληνικά: Ρεύμα μετατόπισης

español: Corriente de desplazamiento

فارسی: جریان جابجایی

français: Courant de déplacement

한국어: 변위 전류

हिन्दी: विस्थापन धारा

italiano: Corrente di spostamento

kurdî: Herikandina guhertine

latviešu: Nobīdes strāva

magyar: Eltolási áram

मराठी: विस्थापित धारा

日本語: 変位電流

norsk: Maxwells forskyvningsstrøm

norsk nynorsk: Forskyvingsstraum

polski: Prąd przesunięcia

português: Corrente de deslocamento

русский: Ток смещения (электродинамика)

slovenčina: Posuvný prúd

Türkçe: Yer değiştirme akımı

اردو: ہٹاؤ جار

中文: 位移電流