Question
Physics Question on Magnetic properties of materials
For formation of permanent magnets, the material should have:
A
high coercivity
B
low coercivity
C
high retentiviry
D
both (a) and (c)
Answer
both (a) and (c)
Explanation
Solution
The material for a permanent magnetic should have high retentivity so that the magnet is strong and high coercivity so that the magnetisation is not wiped out by stray external fields mechanical ill treatment and temperature changes. The hysteresis loss is immaterial because the material in this case is never put to cyclic changes of magnetisation.