A bar magnet of uniform cross-section has its North pole at the left end and its…
PHYSICS · Multi-part · CBSE · Physics · Magnetism and Matter · Magnetism and Matter
Problem
A bar magnet of uniform cross-section has its North pole at the left end and its South pole at the right end. The magnet is placed on a non-magnetic table and struck sharply at its midpoint so that it cleaves cleanly into two equal pieces, A and B, separated by a small air gap.
Answer the following questions about the physical consequences of this fracture.
(a) Before the magnet is broken, describe the distribution of magnetic poles and the general pattern of external magnetic field lines surrounding the bar.
(b) After the break, identify and label the magnetic poles that appear on the newly exposed faces of pieces A and B. Explain, in words, why no isolated magnetic monopole is produced by the fracture.
(c) A plastic rod carrying a uniform positive charge is imagined to be broken in half. Compare and contrast the charge distribution on the two halves of the plastic rod with the pole distribution on pieces A and B of the magnet.
(d) Describe qualitatively how the external magnetic field lines of the system change as a result of the break. In your answer, comment on both the region far from the magnet and the region in the immediate vicinity of the air gap.