Question

Consider the following statements and choose the correct option.
1. Magnetic field lines form closed loops.
2. No two field lines intersect.

• A. Only 1 is true
• B. Only 2 is true
• C. Both 1 and 2 are true
• D. Both 1 and 2 are false

Answer 1

The correct option is C Both 1 and 2 are true

Magnetic field lines originate from the north pole of a magnet and go to the south pole of the magnet. This is inferred by taking a compass and marking the direction where the compass points at different places around the magnet. When we join the points, the line originates from the north pole and ends in the south pole. Inside the magnet, the magnetic field lies go from south pole to the north pole. Hence, they form closed loops.

Also, as we see, no two magnetic field lines intersect.

The figure above shows two intersecting field lines. The direction of field at any point is given by the direction of tangent drawn on the field line passing through the point. At the point of intersection of two magnetic field lines, two tangents are possible, one on each field line. This would mean that the compass will point at two possible directions at the point of intersection. This is not possible, since we know that at a point near the magnet, the compass will point in one direction only. Hence, magnetic field lines don’t intersect.