Fields in Magnetic Materials

This chapter discusses the fields in magnetic materials. It studies forces due to steady electric, steady magnetic, and combined fields on moving charges. It studies forces on differential line, surface, and volume current elements and forces between differential current elements. Force per unit length on a current filament. It also explores the conditions for equality of electric and magnetic forces. This includes force and torque on closed circuits and defines magnetic dipole moment. It classifies magnetic materials as diamagnetic, paramagnetic, ferromagnetic, ferrimagnetic, anti-ferromagnetic, and supermagnetic, and describes their properties. It presents various aspects of B-H curve and the B-H (or hysteresis) loop including its saturation, retentivity, coercivity, and shape. It describes the meaning of magnetization, magnetic susceptibility, and relative permeability. This chapter also describes the boundary conditions for H, B, and M fields and discusses an alternative approach to these.