Q 12-05-065JEE MainJEE Main 2020 (2 Sep, Shift 1)Easy
Magnetic materials used for making permanent magnets $(P)$ and magnets in a transformer $(T)$ have different properties. Which of the following properties best matches the type of magnet required?
Answer: (D) $P$: Large retentivity, large coercivity
A permanent magnet must keep strong magnetisation (large retentivity) and resist demagnetisation (large coercivity).
A transformer core is taken round the hysteresis loop many times a second, so it needs low coercivity and low retentivity (small loop area, low loss).
Solution by Sreeraj P, M.Sc Physics