Magnetic Lines of Force

(a)       The imaginary lines which represent the direction of magnetic field, are known as magnetic lines of force.

(b)       The imaginary path traced by an isolated (imaginary) unit north pole is defined as a line of force.

(c)        Magnetic lines of force are closed curves. Outside the magnet their direction is from north pole to south pole and inside the magnet these are from south to north pole.

(d)       They neither have origin nor end.

(e)       These lines do not intersect, because if they do so then it would mean two value of magnetic field at a single point, which is not possible.

(f)        The tangent drawn at any point to the line of force indicates the direction of magnetic field at that point.

(g)       At the poles of the magnet the magnetic field is stronger because the lines of force there are crowded together and away from the poles the magnetic field is week. i.e. magnetic field intensity ? number of lines of force.

(h)       The number of magnetic lines of force passing through unit normal area is defined as magnetic induction (B) whereas the number of lines of force passing through any area is known as magnetic flux.

  (i)         The lines of force can emerge out of the north pole of magnet at any angle and these can merge into the south pole at any angle.

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