This lecture discusses the application of Maxwell's equations in evaluating the magnetic field strength (H) derived from the magnetization (M) of materials. It begins with an introduction to magnetic materials, particularly iron and its oxides, highlighting their magnetic properties and behaviors. The instructor reviews the fundamental concepts of Maxwell's equations as they pertain to polarizable matter, emphasizing the relationship between electric and magnetic fields. The lecture covers the characteristics of magnetic fields, including the distinction between magnetic field density (B) and magnetic field strength (H), and the implications of stray fields both inside and outside magnetic devices. The discussion extends to practical applications, such as transformers and the use of Halbach arrays in enhancing magnetic field efficiency. The instructor emphasizes the importance of understanding these principles for future experiments and applications in magnetic technologies, providing a comprehensive overview of the theoretical and practical aspects of magnetism in modern engineering.