Demonstrative Video
Hysteresis Loss
When \(H\) is applied, the magnetic material is magnetised and the molecular magnets are lined up in a particular direction.
However, when \(H\) is reversed, the internal friction of the molecular magnets opposes the reversal of magnetism, resulting in hysteresis.
To overcome this internal friction of the molecular magnets (or to wipe off the residual magnetism), a part of \(H\) is used.
The work done by \(H\) against this internal friction of molecular magnets produces heat.
This energy, which is wasted in the form of heat due to hysteresis, is called hysteresis loss.
Hysteresis loss occurs in all the magnetic parts of electrical machines where there is reversal of magnetisation.
This loss results in wastage of energy in the form of heat.
Consequently, it increases the temperature of the machine which is undesirable.
Therefore, a suitable magnetic material is selected for the construction of such parts, e.g., silicon steel is most suitable in which hysteresis loss is minimum.
Importance of Hysteresis Loop
