This book is the modest attempt by the author based on his more than twenty five years of teaching experience to meet the challenging requirement of a textbook on Electronics. Each chapter of the book begins with principles and theorems followed by applications and graded sets of solved problems and review questions. The problems are based on practical data to familiarize the students with practical orders of magnitude. The book will thus greatly enhance the readers' self-confidence and stimulate interest in them for the subject. The whole text including appendices and bibliography will effectively guide the readers for independent study.