The document discusses magnetism and magnetic fields. It compares the magnetic energy storage of different magnetic materials, such as a brass-bound lodestone, ferrite block, and NdFeB magnet, noting they each store around 0.4J of energy while their masses differ by a thousand fold. The document also examines the history of magnetism, magnetic fields around current-carrying wires, magnetic domains and domain walls, and applications of ferrites such as in electronic inductors, transformers, and electromagnets.

4. What is Magnetic Field...?

5. Magnetism

6. History of Magnetism

9. Magnetic field loops around a current carrying wire

20. Origin of domains

22. Schematic representation of a 180º domain wall

30. Applications

32. Structure of ferrites

46. Queries…?

47. Thank you for your patience