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Draw the circuit symbol for NPN and PNP transistors. What is the difference in the Emitter, Base, and Collector regions of a transistor? - Physics

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Question

Draw the circuit symbol for NPN and PNP transistors. What is the difference in the Emitter, Base, and Collector regions of a transistor? 

Answer in Brief
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Solution

The circuit symbols of the two types of transistors:


Figure (a)


Figure (b)

The difference in the Emitter (E), the Base (b), and the Collector (C) are as follows:

  1. Emitter: It is a thick heavily doped layer. This supplies a large number of majority carriers for the current flow through the transistor
  2. Base: It is the thin, lightly doped central layer.
  3. Collector: It is a thick and moderately doped layer. Its area is larger than that of the emitter and the base. This layer collects a major portion of the majority of carriers supplied by the emitter. The collector also helps dissipation of any small amount of heat generated.   
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Chapter 16: Semiconductors Devices - Short Answer II

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