Concept:Ferromagnetic materials have atoms with permanent magnetic dipole moments that spontaneously align in domains due to strong exchange interactions.
At high temperature (Curie temperature), thermal agitation destroys this ordering, turning the material paramagnetic.
Explanation:Assertion (A) is true because individual atoms in ferromagnetic materials possess a permanent magnetic dipole moment, and strong quantum mechanical interactions cause them to align spontaneously within small regions called domains.
Reason (R) is also true: as temperature rises, thermal energy randomizes the dipole orientations. At the Curie temperature (
Tc​), the domain structure breaks down and spontaneous magnetization disappears.
However, the formation of domains (A) is due to exchange interaction and minimization of magnetostatic energy, not because domains disintegrate at high temperature (R).
Thus, both statements are correct, but (R) does not explain why domains form; it only describes what happens at high temperature.
Answer:Option D: Both (A) and (R) are true but (R) is not the correct explanation of (A).
