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प्रश्न
Write two characteristics of a material used for making permanent magnets ?
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उत्तर
The material used for making permanent magnets should have the following characteristics:
(a) High retentivity: It ensures that the magnet remains strong even after removal of the magnetising field.
(b) High coercivity: It ensures that the magnetism of the material does not get easily lost.
Apart from these two criteria, the material should have high permeability.
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