Q. What are the three transistor configurations?

    The three configurations are common base (CB),common collector (CC) & common emitter(CE). The connection in which the base terminal is made common to both input & output is called CB configuration. the input is fed between the emitter and the base. the output signal is developed between the collector and the emitter or the collector common, we can have what are known as CE or CC configurations,respectively. In all the configurations, emitter-base junction is always forward-biased and the collector-bias junction is always reverse biased. In all the three configuration the transistor is working in the active region.