# What is the average drift speed of conduction electrons in a copper wire of cross-sectional area $1.0 \times 10^{–7}m^2$ carrying a current of $1.5 A$. Assume that each copper atom contributes roughly one conduction electron. The density of copper is $9.0 \times 10^3 kg/m^3$ , and its atomic mass is $63.5 u.$
$\begin {array} {1 1} (A)\;1.9mm/s & \quad (b)\;1.1 mm/s \\ (C)\;2.9 mm/s & \quad (D)\;2.2 mm/s \end {array}$