I have great immense pleasure in presenting this text book to BSc and Engineering and also to Applied Physics as per revised syllabus of Mumbai University, Mumbai. It is written strictly according to the guidelines of the revised syllabus which is brought in effect from June, 2019. It is my humble belief that the text books are among the invaluable resources for successful teaching-learning process, provided they are written within the framework of the aims and objectives laid down and hence, My book is really the honest efforts in that direction. This book is also not an exception to the belief. Much more attention has been paid in simplifying the topics and presenting them in a simple and flawless language. Each concept is lucidly explained and supported by self-explanatory diagrams. A large number of examination oriented problems have been solved in every topic and many are given for practice. The key statements, laws, principles and definitions are printed in italics so that they stand out from the rest of the matter. As per the nature of University question paper, number of objective, short and long answer type questions are Included for self-testing. Every attempt has been made to make the matter easily readable and readily understandable. In fact, the book has been evolved out of a prolonged teaching experience.

I am thankful to the author and publishers of various reference books which we have freely consulted while preparing the manuscript. I fail in our duties if we do not thank our publishers, particularly Mr. Adarsh B, for their expeditious efforts in bringing out this book effectively in time. The final tribute goes to our readers for their diligence and kind attitude about our publications. 

In spite of great care some errors, misprints and even mistakes might have crept in. I shall be grateful to the teachers and students who will point them out. Suggestions and opinions for improvement of the book are cordially invited.