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The mobility of an electron moving in the electric field ⃗E with the drift velocity ⃗v_d is μ= _____

Asked in GSEB Board July 2022 · Drift velocity, mobility and current density

Answer: (2) (|⃗v_d|)/E

Step-by-step solution

Idea: in a steady field the drift speed is proportional to the field, and mobility is the constant of proportionality.

|⃗v_d|=μ E.

So μ=(|⃗v_d|)/E: the drift speed gained per unit electric field.

Its unit is m² V⁻¹ s⁻¹, and for an electron μ=(eτ)/m, where τ is the relaxation time.

Why the other options are wrong

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