Question

As temperature increases, at Curie temperature

• A. paramagnet becomes ferromagnet
• B. diamagnet becomes ferromagnet
• C. diamagnet becomes paramagnet
• D. ferromagnet becomes paramagnet
• E. ferromagnet becomes diamagnet

Hint:

Curie temperature for Iron is about 1043 K.
Once cooled below this temperature, it regains its ferromagnetic properties.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Magnetic properties of substances change with temperature.
In ferromagnetic materials, individual atomic dipoles are aligned in domains.

Step 3: Detailed Explanation:
As the temperature of a ferromagnetic material increases, the thermal agitation begins to disrupt the alignment of domains.
At a specific temperature called the Curie temperature (\( T_c \)), the thermal energy becomes high enough to completely randomize the domain structure.
At this point, the material loses its strong spontaneous magnetization and behaves like a paramagnetic substance.
Above \( T_c \), the magnetic susceptibility follows the Curie-Weiss law: \( \chi = \frac{C}{T - T_c} \).

Step 4: Final Answer:
At Curie temperature, a ferromagnet becomes a paramagnet.