For an npn bipolar transistor: Draw the band diagram of the device under thermal equilibrium Draw the band diagram of the device under the active mode of operation, and specify the type of bias (forward or reverse) and voltage polarity applied on the emitter-base and base-collector junctions Explain why in the common-emitter configuration this npn bipolar transistor can achieve a high current gain, i.e. =ICIB1 =ICIB1