Why is the base region of transistor usually made thin?

What is active region for transistor?

What is active region for transistor?

Why is the base of a transistor lightly doped ?

Why is the base of a transistor made thin and is lightly doped?

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.

Transistors are made of.