Variation of Electrical Resistivity with Temperature

The resistivity of a material is dependent on the temperature. Different materials do not exhibit the same dependence on temperatures.

ρ_T = ρ₀ [1 + α (T–T₀)]

where ρ_T is the resistivity at a temperature T and ρ₀ is the same at a reference temperature T₀. α is called the temperature co-efficient of resistivity, and from the dimension of α is (Temperature)^–1.