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The magnitude of the drift velocity per unit electric field is known as ________.

Asked in GUJCET 2024 · Drift velocity, mobility and current density

Answer: (3) Mobility

Step-by-step solution

Idea: in a field E the free electrons acquire a drift velocity v_d proportional to E.

The constant of proportionality is the mobility: μ = (v_d)/E, with SI unit m² V⁻¹ s⁻¹.

For electrons v_d = (eτ)/mE, so μ = (eτ)/m.

So the magnitude of the drift velocity per unit electric field is called the mobility.

Why the other options are wrong

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