Question

At curie temperature, the magnetic property of the substance changes from:

• A. Ferromagnetic to paramagnetic
• B. Paramagnetic to ferromagnetic
• C. Ferrimagnetic to paramagnetic
• D. Ferrimagnetic to Ferromagnetic

Answer 1

The correct option is A Ferromagnetic to paramagnetic

The temperature at which a ferromagnetic substance loses its ferromagnetism and becomes paramagnetic is called Curie temperature.
Substance which shows the property of permanent magnetism even in the absence of the magnetic field are called Ferromagnetic substances.
Iron, nickel, cobalt, gadolinium, $Cr{O}_2$ are examples of ferromagnetic substances.

Substances which are weakly attracted by an external magnetic field, due to presence of unpaired electrons are called paramagnetic substance.
Paramagnetic substances are magnetised in the same direction as the magnetic field. They lose magnetism in the absence of magnetic field.
$Na,K,O_2,C{u}^{2+}\text{and}F{e}^{3+}$ ions are examples of paramagnetic substances.

The Curie temperature is named after Pierre Curie, who showed that magnetism was lost at a critical temperature where ferromagnetic substances get converted into paramagnetic substances.