Question

What is the function of RE in the CE short circuit gain obtained with hybrid pi model?

(a) To improve stability and decrease positive feedback

(b) To improve stability and increase positive feedback

(c) To improve stability and decrease negative feedback

(d) To improve stability and increase negative feedback

This question was addressed to me in a job interview.

I would like to ask this question from The CE Short Circuit Gain Obtained with the Hybrid PI Model in portion High Frequency Transistor of Electronic Devices & Circuits

Answer 1

Correct option is (d) To improve stability and increase negative feedback

The best I can explain: In a CE short circuit gain obtained with hybrid pi model circuit, the emitter resistor provides additional stability along with increasing the negative feedback sent to the collector. The addition of the emitter resistance enables the transistor’s emitter to no longer be grounded to zero – volt potential.