A residence with 120V and 240V loads is likely to be served by which type of transformer?

The appropriate choice for a residence with both 120V and 240V loads is a single-phase transformer with two secondaries. This type of transformer arrangement allows for the variation in voltage needed to serve both types of loads effectively.

In most residential settings, the standard voltage levels are derived from a single-phase transformer that can provide a split phase of 240V. From this 240V supply, the system can create two 120V circuits by utilizing the two secondary windings, each referenced to a common ground or neutral. This configuration is essential for catering to standard household appliances and devices that operate at either voltage.

Having a single-phase transformer with two secondaries allows for flexibility and efficiency, as lights, outlets, and various appliances can operate off the 120V circuits, while larger appliances that require more power can tap into the 240V supply.

The other options, such as three-phase transformers, Delta transformers, and Wye transformers, while relevant in different scenarios, are not typically used for standard residential applications where the focus is on providing both 120V and 240V loads from a single-phase transformer.