question_answer

In BJT, maximum current flows in which of the following?

A)  Emitter region

B) Base region

C) Collector region

D) Equal in all the regions

Correct Answer: A

Solution :

Key Idea: BJT is-a transistor having double poles. In a junction transistor, both the electron and hole play role, hence they are called the bi-polar devices or the bi-polar transistors and they are abbreviated as BJT in short form. There are three parts in a transistor; namely emitter, base and collector. In the emitter part of the transistor the doping is more and it is less in collector part. The doping is very less in the base part. So, emitter current is actually the sum of base and collector current i.e.,        \[{{I}_{E}}={{I}_{B}}+{{I}_{C}}\] Hence, maximum current flows in emitter region. Note: Figure shown, represents the transistor available in the market.   For   identifying   the electrodes, the collector terminal is generally kept far separated as compared to the remaining two electrodes or a red dot is etched near the collector terminal.