The book is helpful in building electronic projects, study and verify the results, and learn basic electronic circuits. This book guides you to build an electronics project ‘Build Switch and Logic Gates Using Transistors on the Breadboard’ using NPN Transistors 2N2222A. To implement the realization of each ‘logic gate’, you combine two or more NPN transistor switch circuits. Logic gates are semiconductor devices, and we use them as the building block of any digital device. A logic gate