Which of the following is not classified as a conductor?

Insulation is not classified as a conductor because its primary purpose is to limit the flow of electrical current. Conductors, such as aluminum, copper, and silver, are materials that allow electricity to flow through them easily due to the presence of free electrons.

Aluminum, copper, and silver are some of the best conductors used in electrical systems because they have low resistivity, providing a pathway for electric current with minimal energy loss. In contrast, insulation materials, which can include rubber, plastic, and glass, are specifically designed to prevent the passage of electricity and protect against electrical shocks, short circuits, and other safety hazards. Thus, insulation plays a critical role in ensuring safety in electrical applications, whereas conductors facilitate the flow of electrical energy.