In this book about 700 problems have been treated in total; three hundred problems have been worked out providing the required details. Answers for the other four hundred problems have been provided at the end of the book. This book will cater the needs of GATE aspirants and postgraduates in Physical Sciences and certain branches of Engineering aiming for teaching posts in colleges and universities through written tests conducted by U.G.C. The inner feeling of the author is that this book will serve the purpose of students doing their course work in Science and Engineering.