During these years, Electronics has come to the forefront of our culture in Science and Technology. Specifically, Applied Electronics has its major areas of use in industry and technical fields. More and more people of the general mass are showing their keen interest in this subject with a view to building a carrier as a professional or industrialist. Some others find their interest in making it as a hobby. But all these interests need a fundamental knowledge in Electronics. Keeping this in view, the present book has been designed to provide the primary needs to our beginners of the subject. It also meets the requirements of those readers who want to be aware of the basic principles of Electronics. This book has the following outstanding features : (1) The language used here is very simple and can be easily accessible to the readers. (2) The style of presentation of the topics is the same as that of a lecture style in the class. The subject matter is presented in the form of questions and answers. (3) Emphasis has been given on the very concept of the subject matter rather than on mathematical derivations. (4) Ample numerical problems in Electronics have been solved. The book is the outcome of the understanding of the subject from the vast field of works of eminent scholars and authors in Electronics. No. originality has been claimed in preparing this book. The author, being a teacher in Electronics for more than 29 years, has developed a fascination towards this subject, and therefore, has tried his best to make the subject easily understandable by the students.