The relaxation time tauIs nearly independent of applied E field whereas it changes significantly with temperature T. First fact is (in part) responsible for Ohnl's law whereas the second fact leads to variation of p with temperature. Elaborate why ?

The relaxation time tauIs nearly independent of applied E field wherea

1.	The relaxation time tauIs nearly independent of applied E field whereas it changes significantly with temperature T. First fact is (in part) responsible for Ohnl's law whereas the second fact leads to variation of p with temperature. Elaborate why ?
Answer» Solution :Relaxation time is inversely proportional to velocity of electron and ions. Due to external electric field drift velocity changes by order of 1 mm/sec where as due to change in temperature drift velocity changes in order of `10^(2)` m/s . With increase in drift velocity relaxation time `(tau)` DECREASES. Hence, by EQUATION `RHO = (1)/(SIGMA) = (m)/("ne"^(2) tau) ` resistivity INCREASES.

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The relaxation time tauIs nearly independent of applied E field whereas it changes significantly with temperature T. First fact is (in part) responsible for Ohnl's law whereas the second fact leads to variation of p with temperature. Elaborate why ?

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