A copper wire of diameter $1.6mm$ carries a current i. The maximum magnetic field due to this wire is $5 \times 10^{-3} T$. The value of $i$ is

Question

$\begin {array} {1 1} (a)\;40A & \quad (b)\;20A \\ (c)\;10A & \quad (d)\;5A \end {array}$