This primary purpose of this book is to provide a good textbook on control system in simple language so that students with urban as well as rural background can easily understand. As many engineering colleges are situated in rural areas, where competent faculty is difficult to find, it is hoped that this book will enable the students to study the subject by them. The principles of feedback control systems are explained in detail and illustrated with suitable examples. Specifically the contents are selected to suit the syllabus framed by J.N. Technological University and some other Technological Universities. The ultimate aim in studying the control theory is to enable the student to design a suitable controller to obtain the desired response from a given plant.