Electrical Engineering ⇒ Topic : Magnetic Field

Magnetic Field

Just as electric field exists near a charged object, similarly magnetic field exists around a magnet. If an isolated magnetic pole is brought near a magnet, it experiences a force according to Coulomb's laws. The region near the magnet where forces act on magnetic poles is called a magnetic field. The magnetic field is strongest near the pole and goes on decreasing in strength as we move away from the magnet.

   The space (or field) in which a magnetic pole experiences a force is called a magnetic field.

The magnetic field around a magnet is represented by imaginary lines called magnetic lines of force. By convention, the direction of these lines of force at any point is the direction along which an *isolated unit N-pole (i.e. N-pole of 1 Wb) placed at that point would move or tends to move. Following this convention, it is clear that magnetic lines of force would emerge from N-pole of the magnet, pass through the surrounding medium and re-enter the S-pole. Inside the magnet, each line of force passes from S-pole to N-pole (See Fig. (a)), thus forming a closed loop or magnetic circuit. Although magnetic lines of force have no real existence and are purely imaginary, yet they are a useful concept to describe the various magnetic effects.

                                                            figure (a)