A parallel$-$plate capacitor whose plates are $10$ cm$2$ and $0\mathrm{.}2$ cm apart contains a medium

with relative permittivity of $$r $=2$ and conductivity of $=4105($S$/$m$).$ To maintain

a steady current through the medium a potential difference of $120$ V is applied between

the plates. Determine

$($a$)[5$ points $]$ Electric field intensity $$E

and the current density $$ J

$($b$)[5$ points $]$ the power density and the power dissipation

$($c$)[10$ points $]$ the current and the resistance of the medium