How can magnetic and electric fields be demonstrated?

Electric field is always associated with magnetic field.

Explanation:

Relationship between electric and magnetic fields can be explained by the following example. Consider a wire and a magnetic compass placed close together.

When current is flowing through the wire, the needle in the magnetic compass will deflect showing some value indicating the presence of magnetic field during the experiment. This indicates that the electric field is generally accompanied with the magnetic field.

To demonstrate that an electric current (i. e., moving electric charge) generates a magnetic field, all you need do is simply place a magnetic compass next to a wire in a circuit. When current is passed through the wire, the compass will deflect, indicating the presence of a magnetic field circling the wire.