What is the Importance of transistor action?

What is the Importance of transistor action?

- The input circuit (i.e. emitter-base junction) has low resistance because of forward bias whereas output circuit (i.e. collector-base junction) has high resistance due to reverse bias. As we have seen, the input emitter current almost entirely flows in the collector circuit. Therefore, a transistor transfers the input signal current from a low-resistance circuit to a high-resistance circuit.
- This is the key factor responsible for the amplifying capability of the transistor. We shall discuss the amplifying property of transistor later in this chapter.


Note: There are two basic transistor types : the bipolar junction transistor (BJT) and field effect transistor (FET). As we shall see, these two transistor types differ in both their operating characteristics and their internal construction. Note that when we use the term transistor, it means bipolar junction transistor (BJT). The term comes from the fact that in a bipolar transistor, there are two types of charge carriers (viz. electrons and holes) that play part in conduction. Note that bi means two and polar refers to polarities. The field-effect transistor is simply referred to as FET.

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Wilfykil answered the question on August 14, 2019 at 12:37

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