Question

Required smoke alarms shall receive their primary power from the building wiring, and when primary power is interrupted, shall receive power from a ____.

1) Generator
2) Battery
3) Solar panel
4) Fuel cell

Answer 1

The correct answer is Battery. Required smoke alarms receive their primary power from the building wiring, but when the primary power is interrupted, they rely on batteries to provide power.

Step-by-step explanation:

The correct answer is Battery. Required smoke alarms receive their primary power from the building wiring, but when the primary power is interrupted, they rely on batteries to provide power.

A smoke alarm contains an electric circuit with two metal plates and a battery. The battery creates a voltage between the plates, and when smoke enters the detector, it interrupts the flow of current, triggering the alarm.

For example, inside a smoke detector, the radioactive element americium ionizes the air, creating a small electric current. When smoke particles interfere with the ions, the current reduces, and the alarm is triggered.