Question

Above Curie temperature :

• A. a ferromagnetic substance becomes paramagnetic
• B. a paramagnetic substance becomes diamagnetic
• C. a diamagnetic substance becomes paramagnetic
• D. a paramagnetic substance becomes ferromagnetic

Answer 1

Answer: (A)

a ferromagnetic substance becomes paramagnetic

Answer 2

Ferromagnetism decreases with rise in temperature. If we heat a ferromagnetic substance, then at a definite temperature the ferromagnetic property of the substance suddenly disappears and the substance becomes paramagnetic. The temperature above which a ferromagnetic substance becomes paramagnetic is called the Curie temperature of the substance. Note: The Curie temperature of iron is $770^oC$ and that of nickel in $358^oC$.