Transistor:

An active semi-conductor device with three terminals that is emitter base and collector is known as transistor.

Types of Transistor:

There are two types of transistors.

1. P-N-P transistors in which N-type of material is sandwiched among two P-types materials.

2. N-P-N transistors in which P-type of material is sandwiches among two N-types materials.

Construction:

The central portion of a transistor is known as base and the regions on the left hand side and the right hand side are known as emitter and collector respectively. These three electrodes are given with terminals for connection in the circuit.