Which of the following characteristics of electron determines the current in a conductor?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Drift velocity alone
The free electrons in a conductor move with large random thermal velocities, but in all directions, so their average velocity is zero and they carry no net charge across any section. When an electric field is applied, the electrons acquire a small average velocity opposite to the field, the drift velocity, and only this gives a net flow of charge.
\( I = neAv_d \)
So the current is determined by the drift velocity alone; the thermal (random) motion contributes nothing to it.
Note: A similar question was also asked in CUET (UG) 2022 on 30-08-2022 (Slot 2).
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Current Electricity – …
