Iron filings are sprinkled on a sheet of glass placed over a short bar magnet. The pattern formed by the filings suggests that
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → the magnet has two poles, like the two charges of an electric dipole
The filings line up along the magnetic field lines. They crowd near the two ends and run from one end to the other, much like the field lines of an electric dipole.
Option (1) the magnetic field lines cross each other near the two ends of the magnet — Incorrect. The filings crowd near the ends, but the lines never cross. At a crossing point the field would have two directions.
Option (2) the two ends of the magnet are like poles, as for two equal positive charges — Incorrect. For two like poles, the lines from the two ends would bend away from each other. There would be a point between them with no field. The filings instead run from one end to the other end, as for a positive and a negative charge.
Option (3) the magnetic field is strongest near the middle of the magnet — Incorrect. Most filings gather at the ends. The field of a bar magnet is strongest at the two ends and weakest in the middle.
Option (4) the magnet has two poles, like the two charges of an electric dipole — Correct. The pattern shows a north and a south pole, similar to the positive and negative charges of an electric dipole.
NCERT (2026-27):
The Bar Magnet – “We begin our study by examining iron filings sprinkled on a sheet of glass placed over a short bar magnet. … The pattern of iron filings suggests that the magnet has two poles similar to the positive and negative charge of an electric dipole.”