Question

In a ferromagnetic material, below the curie temperature, a domain is defined as:

• A. a macroscopic region with zero magnetization.
• B. a macroscopic region with saturation magnetization.
• C. a macroscopic region with randomly oriented magnetic dipoles.
• D. a macroscopic region with consecutive magnetic dipoles oriented in opposite direction.

Hint:

Remember the distinction: a single domain in a ferromagnet is fully magnetized (saturated), but the material as a whole can be unmagnetized if the domains are randomly oriented. Applying an external magnetic field aligns these domains.

Answer 1

The Correct Option is B

Ferromagnetic materials are characterized by the formation of magnetic domains below the Curie temperature.
A magnetic domain is a region within the material where the magnetic moments of the atoms are aligned in the same direction due to strong quantum mechanical exchange forces.
This spontaneous alignment results in the region being magnetically saturated, meaning it has a strong, uniform magnetization in a specific direction.
Overall, an unmagnetized ferromagnetic material has many such domains with their magnetization directions oriented randomly, leading to a net magnetization of zero.
However, the definition of a single domain is a region of uniform, saturated magnetization.
Therefore, option (B) is the correct definition.