A. The drift velocity of electrons decreases with the increase in the temperature of conductor.
B. The drift velocity is inversely proportional to the area of cross-section of given conductor.
C. The drift velocity does not depend on the applied potential difference to the conductor.
D. The drift velocity of electron is inversely proportional to the length of the conductor.
E. The drift velocity increases with the increase in the temperature of conductor.
Choose the correct answer from the options given below:
Answer: (B) A and D only
For a conductor across a potential difference $V$:
$$v_d = \frac{eE\tau}{m} = \frac{eV\tau}{mL}$$
A: True. A higher temperature shortens the relaxation time $\tau$, so $v_d$ decreases (E is false).
B: False. For a given $V$, $v_d$ does not depend on the area.
C: False. $v_d \propto V$.
D: True. $v_d \propto \dfrac1L$.
A and D only.
Solution by Sreeraj P, M.Sc Physics