AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
If two field lines crossed, the compass needle at that point would point in two directions simultaneously, which is impossible. Hence, magnetic field lines never cross each other.
The key reason is from the textbook: at a point of intersection, the magnetic field would have two directions at once, which is physically impossible since a field has only one direction at any given point. Always state this reason clearly for full marks.