Which statement about the secondary power source is true?

Which statement about the secondary power source is true?

• A. There is only one source of power.
• B. The primary power source is the battery.
• C. The secondary power source is a battery capable of supporting the panel for 24 hours and sounding for at least 5 minutes.
• D. Power is provided by solar only.

Answer: (C)

Two-tier power resilience is at work here: the fire alarm system normally runs on the building’s main electricity, and it has a secondary backup power source to keep operating if that mains power fails. The true statement describes the secondary power source as a battery that can power the control panel for 24 hours and allow the audible alarms to sound for at least 5 minutes. This capacity ensures the system stays alive through a power outage long enough to alert occupants and ride out the outage until power is restored or a generator takes over. The other ideas don’t fit because the standard setup uses more than one power source (primary mains plus battery backup), the primary isn’t the backup battery, and while solar can be used in some off-grid configurations, it’s not the typical sole source for sustaining 24-hour operation with guaranteed 5 minutes of alarm during an outage.

Two-tier power resilience is at work here: the fire alarm system normally runs on the building’s main electricity, and it has a secondary backup power source to keep operating if that mains power fails. The true statement describes the secondary power source as a battery that can power the control panel for 24 hours and allow the audible alarms to sound for at least 5 minutes. This capacity ensures the system stays alive through a power outage long enough to alert occupants and ride out the outage until power is restored or a generator takes over. The other ideas don’t fit because the standard setup uses more than one power source (primary mains plus battery backup), the primary isn’t the backup battery, and while solar can be used in some off-grid configurations, it’s not the typical sole source for sustaining 24-hour operation with guaranteed 5 minutes of alarm during an outage.