The purpose of the heavily doped emitter region is to carry current carriers (either electrons or holes, depending upon the type of transistor) into the base. A typical BJT consists of three terminals – an emitter, a collector, and a base. Bipolar Junction Transistor ConstructionĪ bipolar junction transistor is the most widely used electrical component for the amplification of electrical signals. Holes and electrons are current carriers. An n-type (or a p-type) semiconducting material is sandwiched between two p-type (or two n-type) semiconducting materials. A junction transistor involves two p-n junctions. Transistors are broadly of two types – bipolar junction transistor (abbreviated as BJT) and field-effect transistor. The output power, current, and voltage of a transistor are strictly regulated by the input current. It acts as a gate (or as a switch) in electrical circuits.

It is nearly impossible to imagine a modern-day electrical circuit without a transistor.

A transistor can be defined as a semiconducting electrical component that is majorly used for amplifying electrical signals over large distances.

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