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In a solid metallic conductor with no external electric field applied, the average velocity of the free electrons is
Aequal to the speed of light
Bequal to the drift velocity
Cdirected along the field
Dzero
Answer & Solution
Correct answer: D. zero
1. With no field, electrons move only due to random thermal motion.
2. After each collision the direction of velocity is completely random.
3. The number moving in any direction equals the number in the opposite direction, so the vector average is zero.
4. Hence there is no net current; the answer is D.
_Source: NCERT Class 12 Physics Ch 3 "Current Electricity", p.2_
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