A material is said to be a superconductor if when it is brought down to a critical low temperature it loses its resistivity completely.
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A superconductor is a material that has zero electrical resistance at certain temperatures. For example, in a ring of superconducting material, if you induce a current to flow in a circle, it will continue flowing for ever. So far, it has only been possible to create superconductors at cryogenic (i.e., "supercold") temperatures.
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Superconductivity is a property of a substance at a given temperature, not of a substance at any temperature.
Superconductors are things that have no electrical resistance when they are at low enough temperatures, typically close to absolute zero i.e. 0 Kelvin or about -273 degrees C.
There are also 'high-temperature' superconductors that operate at about 70 degrees K (-203 degrees C).
We haven't yet found a substance that works as a superconductor at room temperature there is a lot of research on-going. The aim is to try to find metal alloys or other substances that will behave as superconductors at temperatures which are much closer to room temperature than to absolute zero i.e. 0 Kelvin or about -273 degrees C.
A conductor that allows electricity to flow easily ~APEX