Describe briefly with the help of a circuit diagram, how the flow of current carriers in a p-n-p transistor is regulated with emitter-base junction forward biased and base-collector junction reverse biased.

The emitter base junction is forward biased with VEE and collector base junction is reverse biased with VCC. The holes in the emitter are pushed into the base by the positive terminal of the battery of voltage VEE. Base is thin and lightly doped. Hence only a few holes combine with electrons in the base. Hence IB is small. Since VCC is large, almost 99% of the holes cross the base and reach the collector. These holes constitute the collector current IC. Therefore, IC ≈ βIB, where β is the current gain of the transistor. A small base current IB controls a large collector current IC.