In figure "A" of the illustrated circuit,...

🔍 Key Concepts

• Study how Rb is physically connected between the collector and the base in figure A. • Recall that a transistor has two junctions: emitter–base and collector–base (collector–emitter path), and only one supply +VCC is shown. • Think about what kind of bias (forward vs. reverse) is normally needed at the base–emitter junction for a common‑emitter amplifier.

💭 Think About

• If you did not have resistor Rb at all, how would you supply the correct DC bias to the base–emitter junction so that a small AC input can be amplified? • Which junction actually needs to be slightly forward‑biased in a normal NPN common‑emitter amplifier, and does Rb help create that condition using the single VCC source? • Look at whether Rb is providing a path for current into the base or into the collector–emitter path, and match that to the wording of the options.

✅ Before You Answer

• Verify which junction in a standard NPN common‑emitter amplifier is normally forward biased and which is reverse biased in normal operation. • Check which answer choices refer to the emitter‑base junction versus the collector‑emitter path, and which talk about forward vs reverse bias. • Confirm from the figure that there is only one DC supply (VCC), so Rb must be replacing a separate battery that would otherwise be used to bias a specific junction.

In figure "A" of the illustrated circuit, what is the main purpose of the bias resistor Rb? Illustration EL-0045

to eliminate the need for an emitter-base battery for establishing reverse emitter-base bias

to eliminate the need for a collector-emitter battery for establishing reverse collector-emitter bias

to eliminate the need for a collector-emitter battery for establishing forward collector-emitter bias

to eliminate the need for an emitter-base battery for establishing forward emitter-base bias

🔍 Key Concepts

💭 Think About

✅ Before You Answer