Which alarm component is typically wired with the largest gauge wire?

• A. Panel board
• B. Door sensor
• C. Siren
• D. Motion detector

Answer: (C)

The main idea is that wiring gauge is chosen by how much current a device needs. Devices that draw more current require thicker (larger gauge) wire to prevent voltage drop and overheating.

A siren needs to push a loud sound, which means it draws a noticeably higher current than other alarm components. To carry that surge reliably, the run to the siren is wired with a larger gauge conductor. Door sensors and motion detectors are low-current devices—their electronics and signaling draw only small amounts of current—so they use thinner wire. The panel is the control hub, and while it powers everything, the power to the siren specifically demands the thicker wire to ensure the siren operates at full volume when the alarm is active.