Question

Assertion : Ferromagnetic substances become paramagnetic above Curie temp.

Reason : Domains are destroyed at high temperature.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (a) Both A and R are true and R is the correct explanation of A

Explanation:

The assertion is true. From Curie Weiss law where the susceptibility

 

If the temperature rises above the Curie temperature T_c, ferromagnetic materials become paramagnetic materials because the domains get destroyed as stated.