Which statement is true regarding online uninterruptible power supply (UPS) systems?

The statement that online uninterruptible power supply (UPS) systems are ideal for commercial applications like data centers is true because online UPS systems provide continuous power to connected devices. These systems are designed to ensure that sensitive electronic equipment, such as servers and network devices found in data centers, receive a constant and regulated power supply.

Online UPS systems utilize double conversion technology, meaning that incoming AC power is converted to DC and then back to AC. This process allows them to provide an uninterrupted power source without any transfer time during power interruptions, making them highly reliable for critical applications where even brief outages can cause significant disruption or data loss.

In contrast, options like requiring manual switching to backup power or turning off during power loss are characteristic of other types of power systems, such as offline or standby UPS systems. These systems are not suited for environments where continuous, high-quality power is necessary. Additionally, the claim that online UPS systems only support basic household appliances is incorrect, as they are specifically designed to handle the more complex and demanding power needs found in commercial settings, further solidifying their applicability in data centers.