Answer
(a) $4.3mT$
(b) $230A$
Work Step by Step
(a) We know that
$B=\mu_{\circ}nI$
We plug in the known values to obtain:
$B=(4\pi\times 10^{-7})(0.55)(0.622)$
$B=0.0043T=4.3mT$
(b) We know that
$I=\frac{2\pi rB}{mu_{\circ}}$
We plug in the known values to obtain:
$I=\frac{2\pi(0.0105)(4.3\times 10^{-3})}{4\pi \times 10^{-7}}$
$I=230A$
