Question

In a permanent magnet at room temperature

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

Answer 1

The correct option is A

domains are partially aligned.

In the absence of magnetic field in ferromagnetic substance domains are randomly spread. So resultant magnetic moment is about zero.

After keeping the permanent magnet in a room temperature for long-time individual atoms align themselves in same direction and due to same magnetic orientation, it forms a dipole, which has a working north and south pole. So, the magnetic domains are partially aligned.

Final Answer: (c)