$-12\mathrm{.}29.$ Having discovered the polarity of feed$-$

back, the student in Problem $12\mathrm{.}28$ mod

ifies the circuit as shown in Fig. $12\mathrm{.}94.$

Determine the closed$-$loop gain and $1/$O

impedances of the circuit and compare

the results with those obtained in Prob$-$

lem $12\mathrm{.}27.$

$12.29!!$