A transistor consists of two PN diodes connected back to back. It has three terminals namely emitter, base and collector. The basic idea behind a transistor is that it lets you control the flow of current through one channel by varying the intensity of a much smaller current that's flowing through a second channel.

How does current flow through a transistor?

NPN transistors let the current flow from the emitter to the collector and base controls the flow of current through it. While PNP transistors are designed to pass the current from the collector to the emitter.

What does a transistor do in a circuit?

A transistor is a device that regulates current or voltage flow and acts as a switch or gate for electronic signals. Transistors consist of three layers of a semiconductor material, each capable of carrying a current.