Ominaisvastus

Ominaisvastus, often translated as resistivity, is an intrinsic property of a material that quantifies how strongly that material opposes the flow of electric current. It is a fundamental characteristic that depends solely on the material itself and its temperature, not on the shape or size of the object made from that material.

The concept of ominaisvastus is closely related to electrical resistance. Resistance is a property of a specific object and depends on its dimensions (length and cross-sectional area) as well as the material's ominaisvastus. Ominaisvastus can be understood as the resistance of a unit cube of the material. Its SI unit is the ohm-meter (Ω·m).

Materials with low ominaisvastus, such as copper and silver, are considered good conductors because they allow electric current to flow easily. Conversely, materials with high ominaisvastus, like rubber and glass, are known as insulators as they significantly impede the flow of electricity. Ominaisvastus plays a crucial role in electrical engineering and material science, influencing the design and selection of materials for various applications, from power transmission lines to electronic components. Temperature significantly affects ominaisvastus; for most conductors, it increases with temperature, while for semiconductors and insulators, it generally decreases.