ARRL Technician Practice Exam

Which type of switch is typically used in most household light switches?

1. Double-pole double-throw

2. Single-pole single-throw

3. Triple-pole single-throw

4. Single-pole double-throw

The correct answer is: Single-pole single-throw

The correct choice discusses the single-pole single-throw switch, which is indeed the most common type of switch used in household light fixtures. This type of switch is designed to control a single light or a group of lights from one location. The simplicity of the single-pole single-throw configuration—where one input terminal connects to one output terminal—makes it easy to operate and install, which is ideal for residential use. In household applications, the single-pole single-throw switch simply interrupts or completes the circuit, allowing the flow of electricity to power the light when the switch is in the 'on' position and cutting off the current when turned 'off.' This functionality aligns with typical lighting needs in most homes, making it a practical choice for everyday use. The other types of switches mentioned serve more specialized applications. For instance, the double-pole double-throw switch is used in circuits where there is a need to control a load from two different sources or configurations. The triple-pole single-throw switch is less common and is typically used in three-phase electric circuits, while the single-pole double-throw switch allows for alternate paths for a current and is used when switching between two devices or circuit paths.