This book [earlier titled as Electromagnetism: Theory and Applications which is bifurcated into two volumes: Electromagnetism: Theory and Electromagnetism: Applications (Magnetic Diffusion and Electromagnetic Waves) has been updated to cover some additional aspects of theory and nearly all modern applications. The semi-historical approach is unchanged, but further historical comments have been introduced at various places in the book to give a better insight into the development of the subject as well as to make the study more interesting and palatable to the students. Key Features • Physical explanations of different types of currents • Concepts of complex permittivity and complex permeability; and anisotropic behaviour of constitute parameters in different media and different conditions • Vector co-ordinate system transformation equations • Halbach magnets and the theory of one-sided flux • Discussion on physical aspects of demagnetization curve of B-H loop for ferromagnetic materials • Extrapolation of Frohlich-Kennely equation used for the design and analysis of permanent magnet applications • Physical aspects of Faraday’s law of electromagnetic induction (i.e., Fourth Maxwell’s field equation) through the approach of special relativity • Extrapolation and elaboration of the concept of electromechanical energy conversion to both magnetic as well as electric field systems Appendices contain in-depth analysis of self-inductance and non-conservative fields (Appendix 6), proof regarding the boundary conditions (Appendix 8), theory of bicylindrical co-ordinate system to provide the physical basis of the circuit approach to the cylindrical transmission line systems (Appendix 10), and properties of useful functions like Bessel and Legendre functions (Appendix 9). The book is designed to serve as a core text for students of electrical engineering. Besides, it will be useful to postgraduate physics students as well as research engineers and design and development engineers in industries.