JEE Main202623 January 2026Morning ShiftPhysicsMagnetic Properties of MatterActual
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
Options
- A(A) is true but (R) is false
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is false but (R) is true
- DBoth (A) and (R) are true and (R) is the correct explanation of (A)
Correct answer
B. Both (A) and (R) are true but (R) is not the correct explanation of (A)
Step-by-step solution
Assertion (A) states that individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact to form domains. This is a correct description of the domain theory of ferromagnetism, where exchange interactions lead to spontaneous alignment of moments within small regions called domains. Reason (R) states that at high temperatures (above the Curie temperature T_C ), the domain structure disintegrates due to thermal agitation, and the material becomes paramagnetic. This is also a correct stateme