At what temperature iron becomes paramagnetic?

Question

At what temperature iron becomes paramagnetic? (A) 200°C  (B) 400°C  (C) 600°C  (D) 800°C

Tardigrade Admin · Accepted Answer

When a ferromagnetic material is heated above a certain temperature (called Curie temperature), the exchange coupling suddenly disappears.
The substance, therefore starts behaving as paramagnetic.
Curie temperature for iron is about

800 K

.
Note For cobalt, it is

1375 K

and for nickel, the curie temperature is

625 K

.

Q. At what temperature iron becomes paramagnetic?

$20 0^{\circ} C$

$40 0^{\circ} C$

$60 0^{\circ} C$

$80 0^{\circ} C$

Q. At what temperature iron becomes paramagnetic?

200∘C

400∘C

600∘C

800∘C

$20 0^{\circ} C$

$40 0^{\circ} C$

$60 0^{\circ} C$

$80 0^{\circ} C$