The number density of free electrons in copper is nearly 8 × 10 28   m - 3 . A copper wire has its…

The formula to calculate the current through any conductor is given by

$I=nAe{v}_d ...\left(1\right)$

Substitute the values of the given parameters into equation (1) and solve to calculate the required drift velocity of the electrons.

$\begin{array}{rcl}3.2& =& 8\times {10}^{28}\times 2\times {10}^{-6}\times 1.6\times {10}^{-19}\times v_d\\ & \Rightarrow & v_d=\frac{3.2}{16\times 1.6\times 1000} \mathrm{m} {\mathrm{s}}^{-1}\\ & =& 125\times {10}^{-6} \mathrm{m} {\mathrm{s}}^{-1}\end{array}$