Solution

The properties of magnetic field lines are: (1) They are dense close to the poles and sparse away from them. It means the magnetic field is strongest around the poles of the magnet. (2) They emerge from the north pole of a magnet and enter at the south pole of the magnet. (3) Inside the magnet, the direction of field lines is from the south pole to its north pole. Hence, magnetic field lines are closed curves. (4) The relative strength of the magnetic field is shown by the degree of closeness of the field lines; crowded field lines represent the strong magnetic field. (5) The magnetic field at any point is represented by the tangent at that point. (6) No two field lines intersect each other. If they intersect, it would mean that at the point of intersection there would be two field directions which is not possible. (7) Magnetic field is a quantity that has both direction and magnitude.