Q 12-03-147JEE MainJEE Main 2023 (8 Apr, Shift 1)Easy
A current of $2$ A flows through a wire of cross-sectional area $25.0\ \text{mm}^2$. The number of free electrons in a cubic metre are $2.0\times10^{28}$. The drift velocity of the electrons is ______ $\times10^{-6}\ \text{m s}^{-1}$ (given, charge on electron $=1.6\times10^{-19}$ C).
Numerical value type. Enter your answer.
Answer: 25
$$v_d=\frac{I}{neA}=\frac{2}{2\times10^{28}\times1.6\times10^{-19}\times25\times10^{-6}}=2.5\times10^{-5}\ \text{m s}^{-1}=25\times10^{-6}\ \text{m s}^{-1}$$
Solution by Sreeraj P, M.Sc Physics