Question

Which of the following will be suitable to demagnetize a magnet?
1. Keep in contact of Iron
2. Cooling
3. Putting in water
4. Hammering of Magnet

Answer 1

Correct Answer - Option 4 : Hammering of Magnet

The correct answer is Hammering of Magnet.

• The magnet can de be demagnetised by:
  • heating past the Curie point,
  • applying a strong magnetic field,
  • applying alternating current, or
  • hammering the metal. 

• With the help of magnetic susceptibility, magnetic materials can be classified as:
• Paramagnetic material:
  • Magnetic materials that align with the magnetic field are known as paramagnetic materials.
  • Magnetic susceptibility is χ > 0 which means it is always a small positive value for paramagnetic materials.
  • For example Alkaline earth metal, aluminium, oxygen.
• Diamagnetic material:
  • Magnetic materials that align against the magnetic field are known as diamagnetic materials.
  • Magnetic susceptibility is χ < 0 which means it is always a negative value for diamagnetic material.
  • For example Gold, tin, mercury, water.
• Ferromagnetic material:
  • Magnetic materials that are highly magnetized in a magnetic field are known as ferromagnetic materials.
  • These are highly attracted by the magnets and move from weaker fields to stronger fields.
  • For example Iron, cobalt, nickel and their alloys.