What is the function of a switch in an electrical circuit?

The function of a switch in an electrical circuit is to control the flow of electricity by opening or closing the circuit. When the switch is in the "closed" position, it completes the circuit, allowing electrical current to flow to the desired components, such as lights, devices, or appliances. Conversely, when the switch is in the "open" position, it creates a gap in the circuit, stopping the flow of electricity and turning off the connected device. This simple mechanism is crucial for safe and efficient operation of electrical systems, enabling users control over when devices receive power.

The other options reflect different aspects of electrical circuits but do not accurately describe the primary role of a switch. Measuring voltage pertains to tools like voltmeters, increasing current generally involves transformers or amplifiers, and converting electrical energy into heat relates to resistors or heaters. The switch's primary role is distinctly about controlling the flow of electricity, which is why it is described as opening or closing the circuit.