Question

In a common emitter NPN transistor , how is the collector emitter part reverse biased even though both are n regions?

Answer 1

If you see the working .. you ll see that.. the emitter region electrons go into the P region base.. but since base is very slightly doped.. only some electrons combine with holes and form a base current.. what happens to the rest of the electrons??? you need the rest of the electrons to cross the barrier and go into the collector (N type) right??.. for that you need a positive connected to N type right??. hence collector base junction is always reverse biased..