Question

What is the most common bias circuit?

(a) Base

(b) Collector

(c) Emitter

(d) Voltage-divider

I had been asked this question in quiz.

Asked question is from Input Bias and Offset Currents of the Bipolar Differential Amplifier topic in section Differential and Multistage Amplifiers of Electronic Devices & Circuits

Answer 1

Right choice is (d) Voltage-divider

The explanation: Due to the best stabilization, voltage divider circuit is commonly used. Under this biasing technique, the transistor always remains in the active region. In voltage divider biasing, the voltages at the transistor’s base, emitter and collector all depend upon the external circuit i.e. the biasing resistors R1 and R2 whose valued are fixed thus variation with beta is not present here.