Which of the following is NOT a component of an electrical circuit?

Insulators play a vital role in ensuring the safety and functionality of electrical circuits, but they are not considered a direct component of an electrical circuit itself. The primary components of an electrical circuit include a power source, such as a battery or generator, which provides the necessary voltage; a switch that allows for control of the current flow; and devices like transformers that can modify voltage levels and current characteristics.

While insulators are essential for preventing unintended current flow and protecting components from short circuits or overloads, they do not actively participate in the circuit's operation or functionality. Instead, they serve as protective barriers to ensure safety. This distinction clarifies why insulators are not categorized as a core component of an electrical circuit, unlike the others listed.