Why should the material used for making permanent magnets have high coercivity?
Answer: So that its magnetisation is not easily destroyed by stray fields, rough handling or temperature changes.
Solution
Coercivity is the reverse magnetising field needed to demagnetise a material. A permanent magnet must retain its magnetisation, so it needs a \emph{high} coercivity — then ordinary stray magnetic fields or temperature variations cannot wipe out its magnetism.
CBSE Class 12 Board · 2007 · Subjective