With reference to the amplifier whose frequency response is shown in Fig $1-20,$ find

$($a$)$ the unity$-$gain frequency,

$($b$)$ the gain$-$bandwidth product,

$($c$)$ the bandwidth when the feedback ratio is $0\mathrm{.}02,$ and

$($d$)$ the closed$-$loop gain at $0\mathrm{.}4$ MHz when the feedback ratio is $0\mathrm{.}04.$

$[$Answers: $($a$)1$ MHz $,($b$)\backslash (10^\{6\}\backslash ),($c$)20$ kHz $,($d$)2\mathrm{.}5]$

Fig. $1-20$