virranjohtavuus

Virranjohtavuus, often translated as electrical conductivity, is a fundamental property of materials that describes their ability to conduct electric current. It is the reciprocal of electrical resistivity. A material with high virranjohtavuus allows electric charge carriers, typically electrons, to move through it easily, encountering little resistance. Conversely, a material with low virranjohtavuus, or high resistivity, impedes the flow of charge carriers.

Metals like copper, silver, and gold are excellent conductors due to their abundant free electrons. These materials have very high virranjohtavuus. Insulators, such as rubber, glass, and plastics, have extremely low virranjohtavuus, meaning they resist the flow of electricity effectively. Semiconductors, like silicon and germanium, fall between conductors and insulators, with their virranjohtavuus being controllable and sensitive to external factors like temperature and impurities.

The unit of virranjohtavuus in the International System of Units (SI) is siemens per meter (S/m). Temperature significantly affects virranjohtavuus. For most conductors, virranjohtavuus decreases as temperature increases because increased thermal vibrations of atoms hinder electron movement. For semiconductors, virranjohtavuus generally increases with temperature as more charge carriers are liberated. Understanding virranjohtavuus is crucial in designing electrical circuits, electronic components, and for material science applications.