Magnetic Materials & Curie Law
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:
Show answer and solution
Answer: (d)
- (A) is true. Neighbouring atomic dipoles in a ferromagnet interact (exchange interaction) and align spontaneously, forming domains.
- (R) is true. Above the Curie temperature, thermal agitation breaks up the domain structure and the magnetisation disappears.
- (R) explains how domains are destroyed at high temperature. It does not explain why they form, which is what (A) states.
- So the answer is (d): both are true, but (R) is not the correct explanation of (A).