The book is divided into 11 chapters; first chapter provide the basic circuit analysis and theorems, second chapter is semiconductor diode, and this chapter gives an idea about the properties of semiconductor, conductor and insulator curves. Chapter three discuss about the power supply and different parts of its, fourth and fifth chapter deals with the bipolar and unipolar junction transistors. Sixth and sevent chapter is related to amplifier and its charactersistics. Chapter eight gives an idea about feedback amplifier and its advantages. Chapter nine is related to oscillators. Chapter ten is devoted to operational amplifier. The last chapter of book is related to digital electronics and number systems.