Question

What are the functions of three regions of the transistor?

Answer 1

Transistor is a semiconductor device used to amplify or switch electronic signals and electrical power . It is a solid semiconducting device having $3$regions in which $2$regions are doped with the same type of semiconductor and the middle region is doped with different type semiconductors. The function of three regions are based on their type size and their biasing.
Step by step answer: Here $3$segments are present in transistor
(A) Emitter -
It is of moderate size and having doped it supplies a large number of majority carriers for the current flow through the transistor
(B) Base -
This is the control segment it is very thin and lightly doped
(C) Collector-
This segment collects a major portion of the majority carries supplied by the emitter The collector side is moderately doped and larger in size as compared to the emitter .

Note: Because of three regions in transistor and $2$ biasing of their poles, there are many uses of transistor which are following as
1.as an amplifier
2.as a switch
3.as oscillators
4.as modulators detectors and in any circuit need to perform function