In the following graph of flux density $(B)$ versus magnetizing force $(H)$,coercivity and retentivity are respectively represented by the points

$A$ ferromagnetic material of volume $10^{-3} \, m^3$ is subjected to a magnetic field with a frequency of $50 \, Hz$. The area of the hysteresis loop is $0.1 \, M.K.S. \, \text{units}$. Calculate the energy dissipated in $1 \, \text{sec}$.

Which of the following is represented by the area enclosed by a hysteresis loop?

The intensity of magnetisation $I$ is plotted against the magnetising field $H$ for different substances. The curves $A$ and $B$ shown in the adjoining figure are associated with

The figure illustrates how $B$,the flux density,inside a sample of ferromagnetic material varies with external magnetic field $B_0$. For the sample to be suitable for making a permanent magnet,

The figure illustrates how $B$,the flux density inside a sample of unmagnetised ferromagnetic material,varies with $B_0$,the magnetic flux density in which the sample is kept. For the sample to be suitable for making a permanent magnet: