Which of these is NOT a property of magnetic field lines?

Correct option is D

Correct Answer: D They repel each other.

Explanation:
Magnetic field lines have specific properties, but the statement that they "repel each other" is not accurate. While magnetic field lines tend to spread out to minimize the energy of the field and maintain maximum separation, this behavior is not due to a repulsive force but rather a result of the field's natural configuration. Below is a breakdown of the key properties of magnetic field lines:

1. They travel from north to south outside the magnet and from south to north inside the magnet, forming continuous closed loops.
2. They never intersect, as this would imply two directions of the magnetic field at a single point, which is physically impossible.
3. They are continuous closed loops, reflecting the absence of magnetic monopoles.
4. The idea that "they repel each other" is a misconception, as there is no actual repulsion between field lines, only the natural spreading due to field configuration.

Information Booster:

•  The density of magnetic field lines indicates the strength of the magnetic field (closer lines = stronger field).
  
•  Magnetic field lines always emerge perpendicular to the surface of a magnet at the north pole and enter perpendicularly at the south pole.
  
• The direction of the field lines at any point represents the direction of the magnetic field at that point.
  
•  Magnetic field lines provide a visual representation of the magnetic force experienced by a magnetic material in the field.
  
•  Field lines are a conceptual tool; they do not physically exist but represent the magnetic field's influence.