Question

Derive an expression for drift velocity of free electron in terms of relaxation time

Answer 1

Answer:

Explanation:

Let vi be the initial velocity of an    electron just after a collision. The   velocity of the electron after the   relaxation time ‘τ’ is given by,

vd = vi + aτ

     =vi-eEτ ÷m

     But just after a collision electron can  be taken at rest ie, vi =0                vd=-eEτ ÷m

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