Question 3-26C1

The common base (CB) amplifier configuration provides the highest voltage gain among the three basic BJT setups (common emitter, common collector). This characteristic stems from its very low input impedance and a relatively high output impedance. A small input voltage swing across the low input impedance can produce a large voltage swing across the high output impedance, resulting in significant voltage amplification. In contrast: A) Common base has a current gain (alpha) slightly less than one, meaning the output current is less than the input current. Common collector offers the highest current gain. C) While having high voltage gain, its low current gain means the common base generally doesn't provide the highest *power* gain; common emitter usually does. D) The common base configuration actually has the *lowest* input impedance, not the highest. Common collector has the highest input impedance.