What is the main function of a transformer?

The main function of a transformer is to change the voltage level of alternating current (AC). Transformers operate on the principle of electromagnetic induction, allowing them to step up (increase) or step down (decrease) voltage levels while maintaining the same frequency of the AC signal. This capability is essential in electrical power distribution systems, where high voltages are required to transmit electricity over long distances efficiently. By increasing the voltage for transmission, transformers minimize energy loss as heat in the conductors. When the electricity reaches its destination, transformers can then step down the voltage to safer, usable levels for homes and businesses.

In contrast, while limiting current flow or storing energy in a circuit are important tasks in electrical engineering, they do not describe the primary role of a transformer. Also, changing the frequency of AC is not something transformers do; instead, they manipulate voltage based on the turns ratio of their coils. Thus, the function of a transformer is distinctly tied to altering voltage levels in AC circuits.