Question

In a permanent magnet at room temperature:

• A. Magnetic moment of each molecule is zero.
• B. The individual molecules have non-zero magnetic moments which are all perfectly aligned.
• C. Domains are partially aligned.
• D. Domains are all perfectly aligned.

Answer 1

The correct option is D

Domains are all perfectly aligned.

Explanation for Correct Option:

Option (D):

1. An object that produces a magnetic field is called a magnet.
2. It attracts unlike poles and repels like poles.
3. Magnets are formed by aligning the small domains inside an object towards the external magnetic field.
4. Different types of magnets are formed depending upon the method and alignment of the domains.
5. For a permanent magnet at room temperature, the domains are all perfectly aligned.
6. They are also known as ferromagnets.

Explanation for Incorrect Option:

Option (A):

1. Diamagnets have zero magnetic fields for each of their molecules, and hence their domains.
2. Diamagnets are known to repel the magnetic field.

Option (B):

1. Paramagnet magnets have non-zero magnetic fields.
2. Paramagnet magnets are known to show partial magnetic characteristics in the presence of a magnetic field.

Option (C):

1. Paramagnet magnets and their domains can partially align with the external magnetic field.
2. Paramagnet magnets are known to show partial magnetic characteristics in the presence of a magnetic field.