Consider the feedback system shown in Figure 12.1. The closed-loop gain is \(A_{f}=-80\) and the open-loop gain is \(A=-2 \times 10^{4}\).

(a) Determine the feedback transfer function \(\beta\).

(b) The closed-loop gain is not to change by more than 0.01 percent when the open-loop gain changes. What is the maximum allowed change in the open-loop gain?

Si + SE So Source A Load Sfb B Figure 12.1 Basic configuration of a feedback amplifier