List the properties of magnetic lines of force?

Hint: Magnetic lines of force indicate the tangent of the curve which provides the direction of the magnetic field at a given point. We can’t see them in reality but are useful in describing many phenomena of magnetism.

Complete step by step answer:
The concept of magnetic lines of force were popularized by British Physicist Michael Faraday to represent a magnetic field visually.
The magnetic field can be explained as the curve and a tangent at any point on the curve gives the direction of the magnetic field at that point. It can be explained as the outward direction at which a north pole would lean to migrate if free to do so.
The properties of magnetic lines of force is given below –
1. Magnetic field lines are closed curves which start in air from the N-pole and end at the S-pole and then return to the N-pole through the interior of the magnet.
2. The lines of force never cross each other. If they cross that would mean there are two directions of the magnetic field at the point of intersection, which is not possible.
3. They start from and end on the surface of the magnet normally.
4. The lines of force have a tendency to contract lengthwise and expand sidewise. This defines attraction between poles and repulsiveness between poles.
5. The relative closeness of the lines of force gives a measure of the strength of the magnetic field which is maximum at the poles.

Note: Always remember that the magnetic lines of force show the path of inclined magnetic fields at specified points. Note that magnetic lines are the visual representation of the magnetic field. Remember Magnetic field is different from magnetic lines.