Question

Which material is used to make electromagnets and why

Answer 1

a insulated wire coil around iron or other magentic material  like nickel , steel etc

Answer 2

Usually, electromagnets are made from ferromagnetic metals like iron. A piece of iron can be used as a core and a roll of copper wire can be used to insulate the core. The iron core must be winded with copper wire and induced with electricity.  

When the electric current passes itself through the winding the iron core becomes itself a magnet by observing the current flow. Soft iron is used as the magnetic property of the core will be banished as soon as the flow of current stopped.