A $0\mathrm{.}1-$m layer copper is deposited atop a very thick slab of nickel. For a field incident on the copper surface $($a$)$ calculate $$ at $1\mathrm{.}0$ GHz$.$ Compare this with $$ at $1\mathrm{.}0$ GHz $(5\%)$ for $($b$)$ a semi$-$infinite slab of copper $(5\%)$ and $($c$)$ a $0\mathrm{.}1-$m thickness of copper by itself. $(5\%)$