A potential difference V $=12\mathrm{.}0$ V is applied between the ends of a conducting wire of length l $=3\mathrm{.}00$ m$,$ diameter d $=5\mathrm{.}00$ mm and resistance R $=12\mathrm{.}0$ m$.$ Determine the current density.

Give your answer in units of MA$/$m$^2.$