What device is commonly used to isolate electrical circuits?

A switch is commonly used to isolate electrical circuits because it serves the specific function of breaking the circuit, thereby stopping the flow of electrical current. This ability to open and close a circuit makes switches crucial for controlling electrical devices and ensuring safety when maintenance or repairs are necessary. By disengaging the circuit, switches allow for safe isolation from the power source, preventing accidental energization of the circuit during servicing.

While other devices may have useful functions in electrical systems, they do not serve the primary purpose of circuit isolation as effectively as a switch. Transformers are utilized for voltage conversion, relays act as electrically operated switches, and fuses are designed to protect circuits from overloads by breaking the circuit when excessive current flows. However, they do not provide the simple on/off control that switches offer for isolating circuits safely.