Question
Hysteresis loops for two magnetic materials A and B are given below:
These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use:
-
A for electric generators and transformers.
-
A for electromagnets and B for electric generators
-
A for transformers and B for electric generators.
-
B for electromagnets and transformers.
Solution
D.
B for electromagnets and transformers.
Area of the hysteresis loop is proportional to the net energy absorbed per unit volume by the material, as it is taken over a complete cycle of magnetisation.
For electromagnets and transformers, energy loss should be low.
i.e thin hysteresis curves.
Also |B|→0 When H = 0 and |H| should be small when B →0.
