Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Consider a ferromagnetic material :
Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains.
Reason (R) : At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature.
In the light of the above statements, choose the correct answer from the options given below :
Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains.
Reason (R) : At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature.
In the light of the above statements, choose the correct answer from the options given below :
- (A)(A) is true but (R) is false
- (B)Both (A) and (R) are true but (R) is not the correct explanation of (A)✓ Correct
- (C)Both (A) and (R) are true and (R) is the correct explanation of (A)
- (D)(A) is false but (R) is true
Answer: (B)
Solution
The individual atomic dipole moments in a ferromagnet interact through the exchange interaction and spontaneously align into domains, so the Assertion is true. Above the Curie temperature thermal agitation destroys this domain ordering and the spontaneous magnetization vanishes, so the Reason is also true. However, the Reason describes the breakdown of ordering at high temperature, which does not account for why domains form in the first place. Both statements are true, but the Reason is not the correct explanation of the Assertion.
JEE Main · 2026 · 23 Jan 2026 · Shift 1 · Single correct option