A current of 2 A flows through a wire of cross-sectional area $25.0 \mathrm{~mm}^2$. The number of free electrons in a cubic meter are $2.0 \times 10^{28}$. The drift velocity of the electron is $\_\_\_\_$ $\times 10^{-6} \mathrm{~ms}^{-1}$ (given, charge on electron $\left.=1.6 \times 10^{-19} \mathrm{C}\right)$