At what power rating does the transformer bank operate?

The power rating of a transformer bank is determined by its capacity to handle the load effectively while maintaining efficiency and reliability. In this case, the correct answer is 25 KVA because it represents a typical size for a transformer bank used in residential or light commercial applications where moderate power requirements are expected.

This rating is suitable for providing adequate power to support various electrical loads while also ensuring that the transformer operates within safe limits. A slightly higher rating may lead to over-sizing, which can reduce energy efficiency, while a lower rating may result in overload situations that risk damage to the transformer.

In practical terms, 25 KVA is a common choice for many applications, balancing capability and economy. Other options like 10 KVA, 50 KVA, and 75 KVA, while potentially applicable in certain contexts, do not align as closely with the requirements typically associated with transformer banks serving mixed residential and light commercial loads. Each of these could be appropriate in different scenarios, depending on the specific demand and application needs.