The following figure shows the variation of intensity of magnetisation with the applied magnetic field intensity for three magnetic materials X, Y and Z. Identify the materials X,Y and Z.
The slope of M-H graph measures the magnetic susceptibility, which is
χm = M / H
Material X: Slope is positive and larger value. So, it is a ferromagnetic material.
Material Y: Slope is positive and lesser value than X. So, it could be a paramagnetic material.
Material Z: Slope is negative and hence, it is a diamagnetic material.