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Define mobility of a charge carrier. Write the relation expressing mobility in terms of relaxation time. Give its SI unit. |
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Answer» Solution :MOBILITY of electrons (or other CHARGE carriers) in a conductor means DRIFT speed of conduction electrons per unit electric field. Mobility`mu = (v_d)/(E )` We know that drift speed of electrons `v_d = (eE)/(m) tau`, where `tau`= RELAXATION time `therefore mu = ( (eE tau)/(m) )/(E )= e/m tau` SI unit of mobility is `m^2 V^(-1) s^(-1)` |
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