This book is prepared as per new course introduced in second semester for engineering students of UP Technical University. It will intend to satisfy the entire requirements of the students preparing for engineering physics-II. Some emerging topics like superconductivity and nanotechnology provide basic informative knowledge to readers. This book is the result of a long teaching experience of authors in this field. Hence presentation of the matter is thoroughly lucid and comprehensive. Way of expression is so simple that a student poor in background of the subject can also be benefited.