Which device helps detect smoke and alert occupants?

• A. Refrigerator
• B. Smoke detector
• C. Light switch
• D. Thermostat

Answer: (B)

Detecting smoke and sounding an alarm to warn occupants is a fire-safety function. A smoke detector is designed to sense smoke in the air and emit a loud alarm, waking people and prompting evacuation. This early alert is crucial for safety, especially when people are sleeping or not actively aware of danger. The other devices serve different purposes—refrigeration, lighting control, and temperature regulation—and they do not monitor for smoke or trigger a fire alarm. Knowing that detectors come in different types (ionization for fast flames and photoelectric for smoke from smoldering fires) and that they should be tested regularly with working batteries helps ensure they function when needed.