Current Attempt in Progress

$($a$)$ Using the data in Table $18\mathrm{.}1,$ compute the resistance of a copper wire $3$ mm $(0\mathrm{.}12$ in $.)$ in diameter and $5$ m $(197$ in$.)$ long.

$($b$)$ What would be the current flow if the potential drop across the ends of the wire is $0\mathrm{.}09$ V $?$

A

$($c$)$ What is the current density?

$\frac{A}{m^2}$

$($d$)$ What is the magnitude of the electric field across the ends of the wire?

$\frac{V}{m}$