Previous Year Question

In a solid metallic conductor, electric current is carried by free electrons. In metals, some outer electrons become relatively free from individual atoms and can move through the conductor. When an electric field is applied, their directed motion produces electric current.

The positive ions of the metal remain bound around fixed positions; therefore, protons and neutrons are not the charge carriers in an ordinary metallic conductor.

Important fact: In other types of conductors, such as electrolytes, positive and negative ions can also carry electric current, but this question specifically refers to a solid conductor.