What is the purpose of a transformer in electrical systems?

The primary purpose of a transformer in electrical systems is to change voltage levels. This is achieved through electromagnetic induction, which allows transformers to either step up (increase) or step down (decrease) the voltage of alternating current (AC) electricity. By adjusting the voltage, transformers enable efficient transmission of electricity over long distances, as high voltages result in lower currents and reduced energy loss due to resistance in the conductors.

Transformers are essential in various applications, such as power distribution networks, where they adjust voltage levels to ensure that electricity is transmitted efficiently and safely from power plants to end users. This capability to change voltage levels is a fundamental aspect of how electrical energy is managed in modern power systems.

In contrast, the other options, while related to electrical systems, do not accurately represent the main function of a transformer. For example, transformers do not store electrical energy, convert AC to DC, or increase current capacity directly; rather, they manage voltage levels to ensure optimal power delivery and usage.