How does a "door/window contact" sensor work?

A "door/window contact" sensor operates by utilizing two components – a magnet and a switch. When the door or window is closed, the magnet aligns with the switch, completing the circuit and keeping the alarm deactivated. However, when the door or window opens, the magnet moves away from the switch, breaking the circuit. This action triggers the alarm system, alerting to a potential entry.

This mechanism is fundamental in security systems as it provides a reliable way to monitor points of entry. The simplicity and effectiveness of this design make it a popular choice for residential and commercial security applications. While the other options describe different types of sensors or functions, they do not accurately convey the operational principle of a door/window contact sensor.