Question

In a feedback network, input voltage is 14V, feedback voltage is 6V and source voltage is 20V. β is in ohms. What is its configuration?

(a) Shunt-Shunt feedback

(b) Shunt-Series feedback

(c) Series-Series feedback

(d) Series-Shunt feedback

I have been asked this question in final exam.

My question is based upon Feedback Connection Types in section General and Feedback Amplifiers of Analog Circuits

Answer 1

Right option is (c) Series-Series feedback

Easiest explanation: Given that input is 14V, feedback is 6V and source is 20 V, we can see

VI = VS – VF, which is voltage mixing. Also, β is in ohms that is voltage/current. Since output of feedback is voltage and input is current, the output has current sampling. Thus, configuration is a series-series feedback/current – series feedback.