The correct option is A is false but R is true
Explanation
Magnetic field lines are visual representations of the magnetic field. A fundamental property of these lines is that the tangent drawn at any point on the curve gives the direction of the net magnetic field at that specific point.
Assertion (A) Analysis:
Incorrect. Two magnetic field lines can never intersect each other, regardless of the strength of the field. The magnetic field at any single point in space represents a net vector sum of all magnetic influences. As a vector, it must have a single, unique direction at any given coordinate. Therefore, intersection is physically impossible.
Reason (R) Analysis:
Correct. This statement correctly describes the logical contradiction that would arise if intersection occurred. If two field lines were to intersect, there would be two distinct tangents at the point of intersection. Since a compass needle aligns with the tangent of the field line, it would be required to point in two different directions simultaneously at that single point. This is a physical impossibility, serving as the proof for why field lines do not cross.
Key Takeaway:
Magnetic field lines never intersect because the net magnetic field at any point in space must have one unique direction.