This book is meant to serve as a textbook of Physics for the undergraduate students of science and engineering. Exhausted treatment of topics in quantum mechanics, statistical mechanics, nuclear Physics, electromagnetic theory, X-rays production, properties and applications and ultrasonics and acoustics of buildings have been presented. These topics have been presented in easy to understand and simple language. Large number of solved numerical have been included to give a Quantitative idea of the subject. Short and Long Answer Type questions and unsolved numerical have been given at the end of each Chapter for practice.