NEETPhysicsMagnetic Properties of Matter
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The magnetic susceptibility of a diamagnetic substance is practically independent of temperature, whereas that of a paramagnetic substance is inversely proportional to absolute temperature. Reason (R): Diamagnetism arises due to the orbital motion of electrons which is unaffected by thermal agitati
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Assertion (A) is correct because the susceptibility of diamagnetic materials does not depend on temperature, while paramagnetic materials follow Curie's law ( 1 T ). Reason (R) is also correct and explains (A). Diamagnetism is an inherent property of all atoms arising from the induced change in the orbital motion of electrons when a magnetic field is applied (Lenz's law). This induced moment is independent of the thermal motion of atoms. In contrast, paramagnetism requires the presence of permanent magnetic dipoles