Resistivity of various Materials

Resistance and hence resistivity of conductor depends on numbers of factors .One of the most important factors is dependence of resistance of metals on temperature. Resistivity of the metallic conductor increases with increase on temperature . when we increase the temperature of the metallic conductor,its constituent atoms vibrate with greater amplitudes then usual.This results to the more frequent collison between ions and electrons . As a result average time between the two successive collision decreases resulting the decrease in drift velocity .Thus increase collison with the increase in tempearture results in increase resistivity . For small temperature variations ,resistivity of the most of the metals varies according to the following relations .

ρ(T)=ρ(T0)[1 + α(T-T0)] p( T ) = p(T0)[1 + α(T – T0)]

Where ρ(T) and ρ(T0) are the resistivies of the material at temperature T and T0 respectively and α is the constant for given materail and is known as coefficient of resistivity