NCIDQ IDFX 2025 – 400 Free Practice Questions to Pass the Exam

Microwave detectors function by emitting microwave radiation, which is a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter. The use of microwave radiation allows these detectors to sense movement and changes in energy levels in their surrounding environment. When microwaves are emitted, they can penetrate various materials, and when they encounter an object, such as a person moving within the detection area, the properties of the reflected microwaves change. This alteration is what the microwave detector picks up to identify presence or motion.

In contrast, the other forms of radiation mentioned do not serve the same purpose or function as effectively for movement detection. Infrared radiation is primarily utilized for thermal sensing, ultrasonic sound involves high-frequency sound waves for detection, and radio waves typically cover broader communication functions. Therefore, the specific nature of microwave radiation is what makes it effective and appropriate for use in microwave detectors, leading to its designation as the correct answer.