$17\mathrm{.}47.$ Make a schematic illustration of an $n-$channel FET analogous to the $p-$channel FET shown in Figure $13\mathrm{.}46.$

FIGURE $13\mathrm{.}46$ Schematic of a field$-$effect transistor $($FET$).$ A negative voltage applied to the gate produces a field under the vitreous silica layer and a resulting p$-$type conductive channel between the source and the drain. The width of the gate is less than $50$ nm in contemporary integrated circuits.