State the characteristics of magnetic field lines.

Explanation

(1) The magnetic field lines emergy from north pole and merge at the south pole outside the magnet , while inside the magnet the direction of field lines is from its south pole to its north pole .
Thus , the magnetic field lines are closed and continuous curve.
(2) The magnetic field lines are crowded near the pole where the magnetic field is strong are far apart near the middle of the magnet and far from the magnet where the magnetic field is weak .
(3) The magnetic field lines never intersect each other because if they do so , there would be two directions of magnetic field at that point which is absurd.
(4) In case the field lines are parallel and equidistance , these represent a unifrom magnetic field .