Find the odd one out regarding processes used to create or strengthen temporary or permanent magnets:

Find the odd one out regarding processes used to create or strengthen temporary or permanent magnets:
  1. Single-touch stroking method
  2. Passing direct electric current through a coil surrounding iron
  3. Double-touch stroking method
  4. Heating a magnet to red-hot temperature

Solution

Single-touch, double-touch, and electric current methods create or strengthen magnets, whereas heating a magnet strongly destroys its magnetism.

Asked in: Homi Bhabha Practice

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