When a ferromagnetic material goes through a hysteresis loop, the magnetic susceptibility
Magnetic susceptibility () is given by formula
..(i)
When a ferromagnetic material goes through a hysteresis loop
At point C:
Magnetic intensity H becomes 0 whereas magnetization I is finite.
From(i) we get
At point G:
Magnetization I, becomes 0 whereas H is finite
From(i) we get
In the second quadrant H is negative whereas I is positive therefore
Becomes negative here
Therefore, when a ferromagnetic material goes through hysteresis loop the magnetic susceptibility may be zero, may be negative and may be infinity.