Q. Transistor terminals in BJT ?

BJTS have three terminals namely base terminal, emitter terminal and collector terminal .The emitter layer is a source of charge carriers and is heavily doped with a moderate cross-sectional area .The collector collects the charge carriers emitted by the emitter region and has a moderate doping and large cross-sectional area. The base is in between these and it acts as a path for the movement of charge carriers .In order to reduce the recombination of electrons and holes in the base region ,this region is lightly doped and is of narrow cross- sectional area. The width of the base region should be less than the diffusion length of the carriers present in the base region. BJT is classified into two types based on the type of semiconductor connected.