What is the purpose of a transformer in a residential electrical system?

In a residential electrical system, the primary purpose of a transformer is to change voltage levels to suit different needs within the system. Transformers adjust the voltage from high transmission levels to lower levels suitable for household use. For instance, electricity is typically delivered to homes at a high voltage to minimize energy loss during transmission over long distances. Once the electricity reaches the neighborhood, transformers reduce the voltage to a safe and usable level for residential devices, which typically operate at 120V or 240V. This voltage adjustment is crucial because different appliances have distinct voltage requirements, and using the appropriate voltage ensures that they operate efficiently and safely.

The other options do not accurately reflect the fundamental role of a transformer in a residential electrical system. For example, transformers are not used to increase current supply; they focus on voltage changes while the current adjusts accordingly based on the load. Additionally, while frequency regulation is essential for electrical systems, it is typically managed by other equipment, not transformers. Lastly, transformers do not convert DC to AC electricity; they only work with alternating current (AC) and rely on the electromagnetic induction principle to function.