What type of materials can be used to make an electromagnet?

The variation of intensity of magnetisation $(I)$ and the applied magnetic field intensity $(H)$ for three magnetic materials $X$,$Y$ and $Z$ are shown in the graph as $OX$,$OY$ and $OZ$ respectively. The materials $X$,$Y$ and $Z$ respectively are:

Consider the regular array of vertical identical current-carrying wires (with the direction of current flow as indicated in the figure alongside) protruding through a horizontal table. If we scatter some diamagnetic particles on the table,then they are likely to accumulate:

What is the value of magnetic susceptibility $\chi$ for:
$(i)$ Paramagnetic material
$(ii)$ Diamagnetic materials

In a ferromagnetic material,below the Curie temperature,a domain is defined as:

An example of a perfect diamagnet is a superconductor. This implies that when a superconductor is placed in an external magnetic field of intensity $B$,the magnetic field $B_s$ inside the superconductor will be such that