IGCSE Computer Science Practice Test

The function of a motion sensor in security devices is primarily to detect the presence of movement. Motion sensors are designed to identify changes in physical space, typically by using various technologies such as infrared, microwave, or ultrasonic waves. When an object, such as a person or an animal, moves within the sensor's coverage area, the sensor triggers an alert or activates a camera, alarm, or other security protocol.

This capability is crucial for security systems because it enables real-time responses to potential intrusions, thereby enhancing the overall safety of a premises. Additionally, motion sensors can help reduce false alarms since they specifically respond to movement rather than just detecting light changes or temperature variations.