$($i$)$ Draw ac equivalent circuit for the small signal JFET amplifier.

$($ii$)$ Determine $\backslash ($ g$\_\{$m$\}\backslash ).$

$($iii$)$ Analyse Z ifor the small signal JFET amplifier

$($iv$)$ Prove that $\backslash (\backslash$mathrm$\{$Z$\}\_\{0\}=\backslash$mathrm$\{$R$\}\_\{\backslash$mathrm$\{$D$\}\}\backslash )$ if $\backslash (\backslash$mathrm$\{$r$\}\_\{\backslash$mathrm$\{$d$\}\}\backslash )$ is included in the network $($show the derivation$).$

$($v$)$ Analyse Av for the small signal JFET amplifier $($show the derivation$).$