Electrical Resistivity
An intrinsic material property quantifying how strongly a material opposes the flow of electric current.
Governing formula
ρ = R A / L = 1 / σ
SI unit
Ω·m (Ohm-meters)
In depth
Resistivity depends on atomic structure, electron scattering mechanisms, and temperature. Good conductors like copper have low resistivity (~1.7 × 10⁻⁸ Ω·m), whereas insulative glass has high resistivity (~10¹⁰–10¹⁴ Ω·m).
Examples in the real world
Copper and aluminum wires chosen for electrical grid cabling due to their exceptionally low electrical resistivity.