The book has been written strictly covering the syllabus of II year (4th Semester) of U.P.T.U., Lucknow. This book is especially meant for the students of Electrical and Electronics Engineering and Electrical Engineering. The book has been divided into four units: Unit 1 deals in crystal structure of materials; Unit 2 describes conductivity of metals; mechanism of conduction in semiconductor materials is given in Unit 3 and Unit 4 explains about the magnetic properties of material. Each and every concept have been given step by step with good number of illustrations to grasp the matter easily. A large number of objective type, short answer type, review questions with practical problems have been included at the end of each chapter for the benefit of the students.About the AuthorDr. S.O. Pillai served as a faculty member in physics in the Department of Technical Education, Tamil Nadu for about 15 years and then moved to Anna University as Reader in Physics in 1978 and promoted as Professor of Physics on acquiring Ph.D. degree in 1984. He guided many M.Sc. and M.Phil. students in their project and two of them earned their Ph. D. degree. Dr. Pillai has about 45 research papers, has authored eight textbooks in Physics and Materials Science. The feedback from his students and testimonials from experts on his all around accomplishments including the one from the then Governor Tamil Nadu helped the management of Anna University recommend him for Dr. Radhakrishnan's Best Teacher Award for 1991. Mrs. Sivakami, a physics graduate of Madras University, worked in two well-established Arts and Science Colleges in the southern districts of Tamil Nadu for about five years. Her Experience as a tutor in conducting the laboratory classes for B.Sc. students and the rich contribution made in preparing the laboratory manual helped her to complete the manuscript preparation in the present form in record time under the guidance of the first author.Table of Contents Unit 1 : Crystal Structure of Materials Unit 2 : Electron Theory of Metals Unit 3 : Mechanism of Conduction in Semiconductors Unit 4 : Magnetism and Magnetic Materials