In the normal working of a transistor , the emitter is forward biased and collector is reverse biased.
a. Comment on the above statement .
b. Can we exchange emitter and collector of a transistor ?
c. Base region of a transistor is made very thin and lightly doped. Why ?
d. "Eventhough the collector - base is reverse biased, the current flow takes place with out experiencing much high resistance" , Give your explanation.

Explanation

a. The movement of electrons from emitter to collector in n-p-n and holes in p-n-p takes place only if the connections are made with emitter forward biased and collector - reverse biased .
b. No
c. A thin and lightly dopped base region will contain smaller number of majority charge carriers . This will reduce the recombination rate of electrons and holes when majority charge carriers move from emitter to collector.
d The reverse potential value is higher than the forward biased potential so that the charges injected to the base region are pulled effectively to the collector region .