Question

Why don’t two magnetic lines of force intersect with each other?

Answer 1

Hint: The magnetic lines of force are constructed around a magnetic material because we want to represent the direction of the magnetic field at all the points around that material. The magnetic field can point along only one direction at a time.

Complete answer:
A magnetic material like a bar magnet exhibits a magnetic field around itself. The magnet has a north pole and a south pole. This field can be visualized in front of lines originating from the north pole of the magnet and ending at the south pole. These hypothetical lines are called magnetic field lines.

Denser the magnetic field lines, greater is the strength of magnetic field at those points. The direction of the magnetic field at a point can be determined using magnetic field lines. The lines are directed from north pole to the south pole outside the magnet while they are directed from south pole to north pole inside the magnet. A tangent drawn on a magnetic field line gives the direction of the magnetic field at that point. The direction can also be determined by using a magnetic compass. When a magnetic compass is placed on a magnetic field line, then it always points in the direction of the magnetic field at that point.
The magnetic field lines never intersect each other because if two or more lines intersect each other than it means that at that point of intersection, the magnetic field has two directions at the same point. This is not possible for a magnetic field to point in more than one direction at the same point.

Note: There cannot exist an isolated north pole or south pole. When magnetic lines of force originate from a north pole they must end at a south pole. Unlike magnets, isolated charges can exist, but a magnetic monopole does not exist in nature.