Introduction

Introduction

• In the last chapter we have studied various basic concepts of magnetostatics and different magnetic field quantities. We studied Biot-Savart law, Ampere's law and physical significance of magnetic flux, magnetic flux density, scalar potential and vector potential.

• With this basic knowledge of the steady magnetic field, let us study now various important concepts such as forces and torques exerted by the magnetic field on other charges. The main difference between the electric field and the steady magnetic field is that, the electric field can exert a force on either stationary charge or the moving charge, while the steady magnetic field can exert a force on only moving charge. Rather the magnetic field is produced due to the moving charges only and not from stationary charges. Thus the magnetic field can exert force only on the moving charges and not on stationary.

• The chapter starts with explanation of force exerted on moving point charge, then on differential current element. The chapter also includes discussion on magnetic torque and magnetic dipole moment.