This textbook is a follow-up to the volume Principles of Engineering Physics 1 and aims for an introductory course in engineering physics. It provides a balance between theoretical concepts and their applications. Fundamental concepts of crystal structure including lattice directions and planes, atomic packing factor, diffraction by crystal, reciprocal lattics and intensity of diffracted beam are extensively discussed in the book. The book also covers topics related to superconductivity, optoelectronic devices, dielectric materials, semiconductors, electron theory of solids and energy bands in solids. The text is written in a logical and coherent manner for easy understanding by students. Emphasis has been given to an understanding of the basic concepts and their applications to a number of engineering problems. Each topic is discussed in detail both conceptually and mathematically, so that students will not face comprehension difficulties. Derivations and solved problems are provided in a step-by-step approach.