Question

A metallic block has no potential difference applied across it, then the mean velocity of free electrons at absolute temperature T is

• A. Proportional to $T$
• B. Proportional to$\sqrt{T}$
• C. Zero
• D. Finite but independent of $T$

Answer 1

Answer: (C)

Zero

When there is no Potential Difference across the block, the motion of electrons will not be systematic. They will move in random motion.

By considering the motion of all the free electron in every possible direction due to randomness, the Average mean velocity of free electrons turns out to be zero.