Rezistivitatea

Rezistivitatea, also known as electrical 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 is independent of the object's shape or size, unlike electrical resistance. The symbol commonly used for resistivity is the Greek letter rho (ρ).

The unit of resistivity in the International System of Units (SI) is the ohm-meter (Ω⋅m). A low resistivity value indicates that a material is a good conductor of electricity, allowing current to flow easily. Conversely, a high resistivity value signifies that a material is a poor conductor, acting as an electrical insulator.

Resistivity is related to electrical resistance (R) by the formula R = ρ(L/A), where L is the length of the conductor and A is its cross-sectional area. This relationship highlights how the geometry of a material influences its total resistance, while resistivity remains a material-specific property. Temperature also significantly affects resistivity; for most conductors, resistivity increases with temperature, while for semiconductors, it generally decreases. Understanding resistivity is crucial in designing electrical circuits, selecting appropriate materials for conductors and insulators, and in various scientific and engineering applications.