A perfect conductor or perfect electric conductor (PEC) is an idealized material exhibiting infinite electrical conductivity or, equivalently, zero

resistivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

(

cf. The abbreviation ''cf.'' (short for the la, confer/conferatur, both meaning "compare") is used in writing to refer the reader to other material to make a comparison with the topic being discussed. Style guides recommend that ''cf.'' be used onl ...

perfect dielectric In electromagnetism, a dielectric (or dielectric medium) is an Insulator (electricity), electrical insulator that can be Polarisability, polarised by an applied electric field. When a dielectric material is placed in an electric field, electr ...

). While perfect

electrical conductor In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. Electric current is gene ...

s do not exist in nature, the concept is a useful model when

electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual paralle ...

is negligible compared to other effects. One example is ideal magnetohydrodynamics, the study of perfectly conductive fluids. Another example is electrical

circuit diagram A circuit diagram (wiring diagram, electrical diagram, elementary diagram, electronic schematic) is a graphical representation of an electrical circuit. A pictorial circuit diagram uses simple images of components, while a schematic diagram s ...

s, which carry the implicit assumption that the wires connecting the components have no resistance. Yet another example is in computational electromagnetics, where PEC can be simulated faster, since the parts of equations that take finite conductivity into account can be neglected.

Properties of perfect conductors

Perfect conductors: *have exactly zero electrical resistance - a steady current within a perfect conductor will flow without losing energy to resistance. Resistance is what causes heating in conductors, thus a perfect conductor will generate no heat. Since energy is not being lost to heat, the current will not dissipate; it will flow indefinitely within the perfect conductor until there exists no potential difference. *require a constant magnetic flux - the magnetic flux within the perfect conductor must be constant with time. Any external field applied to a perfect conductor will have no effect on its internal field configuration.

Distinction between a perfect conductor and a superconductor

Superconductors Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

, in addition to having no electrical resistance, exhibit quantum effects such as the

Meissner effect The Meissner effect (or Meissner–Ochsenfeld effect) is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state when it is cooled below the critical temperature. This expulsion will repel a ne ...

and quantization of magnetic flux. In perfect conductors, the interior magnetic field must remain fixed but can have a zero ''or'' nonzero value. In real superconductors, all magnetic flux is expelled during the phase transition to superconductivity (the

), and the magnetic field is ''always'' zero within the bulk of the superconductor.

Mesoscopic scale

Non-super-conducting metal can produce persistent currents when reduced to a size that is smaller than the electronic

coherence length In physics, coherence length is the propagation distance over which a coherent wave (e.g. an electromagnetic wave) maintains a specified degree of coherence. Wave interference is strong when the paths taken by all of the interfering waves dif ...

. This persistent currents has been demonstrated in noble metal rings of a few micrometers.

References

Superconductivity Computational electromagnetics {{electromagnetism-stub