Which of the following is considered a basic component of an electrical circuit?

A power source is indeed considered a basic component of an electrical circuit because it provides the necessary electrical energy that powers the entire circuit. This energy is typically supplied in the form of voltage, which is essential for the movement of electrons through the circuit. Without a power source, no electrical current can flow, rendering the circuit non-functional.

While other components such as resistors and switches play vital roles in the functioning and control of the circuit, they cannot operate independently without the power source. The transformer, on the other hand, is used to modify voltage levels in AC (alternating current) electricity but is not essential for all types of circuits.