Question

Why is BJT called a transistor?

Answer 1

Hint: In order to solve this question, we should know that a transistor is an electronic device that is generally used to control, amplify and generate electronic signals and also act as a switch in many electronic circuits, here we will discuss about BJT and the reason why it’s considered as a transistor.

Complete step by step solution:
As we know, the term BJT stands for Bipolar Junction Transistor, and BJT is formed by connecting two PN Junctions together and they are named as PNP or NPN bipolar transistors depending upon which layer is sandwiched between the other two.

Now in BJT transistors, the controlled current must be passed through P as well as N layers and their charge carriers are electrons and holes so they have two polarities as compared to some unipolar transistors such as Field-effect transistors.

So, Due to the polar nature of BJT due to the presence of PN junctions, BJT is called Bipolar Junction Transistors. Bipolar Junction Transistors always have three components known as Emitter, Collector, and Base.

Hence, due to the bipolar nature of current flow either due to electrons and holes according to PN junctions forward and reverse bias, BJT is called Bipolar Junction Transistors.

Note: It should be remembered that generally Bipolar Junction Transistor (BJT) is used in electronic circuits as an amplifier, rectifier, filter, oscillator, and most commonly as the switch. and the most advantageous thing about BJT is that they have a low forward voltage and can be operated from low to high power applications.