Demagnetization is the process of reducing or eliminating the magnetism of a material.
Methods of Demagnetization
- Hammering
- Process: Mechanical vibrations disrupt the alignment of magnetic domains, causing them to lose their ordered orientation.
- Heating
- Process: When a magnet is heated, the rapid vibration of atoms disturbs the alignment of magnetic domains, leading to loss of magnetism.
- Direct Current (DC) Method
- Process: The magnet is placed inside a solenoid through which a direct current is passed. The magnet is then slowly removed from the solenoid while the current remains on, causing the magnetic fields to interact and disrupt the magnet’s domains.
- Diagram: [Illustration of magnet inside solenoid with current flow]
- Alternating Current (AC) Method
- Process: The solenoid is connected to an alternating current. The changing magnetic field of AC continuously disturbs the orientation of magnetic domains, leading to demagnetization.
- Diagram: [Illustration of solenoid connected to AC source]
- Storing Without Keepers
- Process: Storing magnets without keepers for extended periods can lead to gradual loss of magnetism.
- Dropping Repeatedly
- Process: Repeated physical impacts can disrupt the alignment of magnetic domains, leading to demagnetization.
Uses of Magnets
- Electrical Devices: Motors, generators, loudspeakers, and microphones.
- Data Storage: Computer memories, floppy disks, hard disks, audio and video cassette tapes.
- Navigation: Compasses.
- Others: Magnetic powders in tapes and various industrial applications.
Storing Magnets
- Using Keepers
- Description: Pieces of soft iron placed across the poles of a magnet to keep magnetic domains aligned, preventing them from repelling each other.
- Storing in Pairs
- Description: Magnets are stored in pairs with their poles aligned oppositely. Soft magnetic material (e.g., iron) is placed at the ends to maintain magnetic alignment.
Diagram: [Illustration of magnets stored with keepers and in pairs]