Which one of the following statements is not true about a bar magnet ?

As per the NCERT chapter, field lines emerge from the north pole and merge at the south pole outside the magnet, but by convention (since field lines are closed curves), inside the magnet the direction of field lines is from the south pole to the north pole, not from north to south. The chapter states explicitly: "Inside the magnet, the direction of field lines is from its south pole to its north pole. Thus the magnetic field lines are closed curves." So statement D is NOT true, making it the correct choice for this question.

• (A) is a true statement — a freely suspended bar magnet always aligns itself along the north-south direction because of Earth's magnetic field; this is the basic property used to identify poles ("north seeking"/"south seeking" pole).
• (B) is true — a bar magnet attracts iron filings/ferromagnetic materials, as demonstrated in Activity 12.2 where iron filings sprinkled around the magnet arrange themselves along field lines due to the attractive force.
• (C) is true — the chapter defines that "the region surrounding a magnet, in which the force of the magnet can be detected, is said to have a magnetic field," and this field is represented by field lines produced by the magnet.
• (D) is false (hence the answer) — the actual direction inside the magnet is south to north, the reverse of what is stated.