GEOLOGY

Detailed explanation-1: -Soft iron and cobalt can be used to make a temporary magnet. These materials behave like magnets only when they are near a strong magnet.

Detailed explanation-2: -A temporary magnet is a magnet made of soft iron, that is usually easy to magnetize; however, temporary magnets lose most of their magnetic properties when the magnetizing cause is discontinued.

Detailed explanation-3: -On the other hand, a temporary magnet has a smaller hysteresis loop as they are made from soft magnetic materials and they do not retain their magnetism once magnetized, for example silicon-iron, aluminum-iron etc. Hence a temporary magnet is made up of soft-iron. So this is the required answer.

Detailed explanation-4: -Soft iron is the type of iron which can be easily magnetized when there is an inducing magnetic field and is demagnetized when the inducing magnetic field is removed. In other words we can say soft iron has high susceptibility and low retentivity.

Detailed explanation-5: -An electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of “soft” ferromagnetic material such as mild steel, which greatly enhances the magnetic field produced by the coil.