# Current Density

In electromagnetism, and related fields in solid state physics, condensed matter physics etc. current density is the electric current per unit area of cross section. It is defined as a vector whose magnitude is the electric current per cross-sectional area. In SI units, the electric current density is measured in amperes per square metre.

### Other articles related to "current density, current, currents, density":

Autobahn - Current Density
... Most sections of Germany's autobahns are modern, containing two or three lanes in addition to an emergency lane (hard shoulder) ... A few other sections remain in an old state, with two lanes, no emergency lane, and short slip-roads and ramps ...
Ampère's Circuital Law - Extending The Original Law: The Maxwell–Ampère Equation
... equation is extended by including the polarization current, thereby remedying the limited applicability of the original Ampère's circuital law ... H-field is (the H-field is used because it includes the magnetization currents, so JM does not appear explicitly, see H-field and also Note) (integral form), where ... proof" section below) In differential form, In both forms J includes magnetization current density as well as conduction and polarization current ...
Magnetization in Maxwell's Equations - Magnetization Current
... The magnetization M makes a contribution to the current density J, known as the magnetization current or bound current so that the total current density that enters Maxwell's ...
Current Density - In Practice
... In electrical wiring, the maximum current density can vary from 4A∙mm−2 for a wire with no air circulation around it, to 6A∙mm−2 for a wire in free air ... Regulations for building wiring list the maximum allowed current of each size of cable in differing conditions ... If the wire is carrying high frequency currents, the skin effect may affect the distribution of the current across the section by concentrating the current on ...
Polarization Density in Maxwell's Equations - Bound Charge
... of the bound electrons in the material, which creates an additional charge density, known as the bound charge density ρb so that the total charge density ... the bound charge appears as a surface charge density with as the normal vector If P is uniform inside the material, this surface charge is the only bound ... When the polarization density changes with time, the time-dependent bound-charge density creates a polarization current density of so that the total current density that enters Maxwell's equations is ...

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