What type of power does a 450 V to 120 V step-down power transformer provide?

The correct choice, which indicates that the transformer provides 3-Phase, 120 V, 60 Hz power, reflects a deeper understanding of how transformers work, especially in relation to the characteristics of the input and output power supply.

A step-down transformer reduces the voltage from a higher level (in this case, 450 V) to a lower level (120 V). The mention of 3-Phase implies that the transformer is designed to handle a three-phase electrical system, which is commonly used in industrial settings due to its efficiency and power capacity compared to single-phase systems. The output voltage of 120 V suggests that the transformer provides a lower voltage suitable for various applications while maintaining the three-phase configuration.

Furthermore, the frequency of 60 Hz is a standard in many regions, particularly in North America, for electrical power. This indicates that the transformer can work effectively within the grid's frequency, ensuring compatibility with other equipment and infrastructure.

The other options, while they may describe possible configurations, do not align with the concept of stepping down from 450 V to 120 V in a three-phase context. For example, a single-phase output is not represented correctly in this scenario, as the system is specified to work as a three-phase transformer.