A ferromagnetic substance becomes a permanent magnet when it is placed in a magnetic field because:

1. All the domains get oriented in the direction of the magnetic field.
2. All the domains get oriented in the direction opposite to the direction of the magnetic field.
3. Domains get oriented randomly.
4. Domains are not affected by the magnetic field.


HINT: Ferromagnetic substances can be permanently magnetized. 
 
Explanation:
When a ferromagnetic substance is placed in a magnetic field it becomes a permanent magnet because all the domains get oriented in the direction of the magnetic field even after removal of the applied magnetic field.

Write three properties of ferromagnetic materials class 12 physics CBSE

Thus, option 1 is the correct answer.