$11\mathrm{.}73$ Consider the feedback current amplifier in Fig. $11\mathrm{.}30($a$)($which was analyzed in Example $11\mathrm{.}10).$ Let $R_s=R_{id}=.$ By setting $I_s=0$ and breaking the feedback loop at the gate of $Q,$ find an expression for the loop gain $A.$ Evaluate $A$ for the component values given in Example $11\mathrm{.}10$ and hence determine A and $A_f.$ Why do the results differ somewhat from those found in Example $11\mathrm{.}10?$