What does a transformer primarily do in an electrical circuit?

In an electrical circuit, a transformer primarily serves the function of changing voltage levels. This device works on the principle of electromagnetic induction, allowing it to step up (increase) or step down (decrease) the voltage of alternating current (AC) electricity. By adjusting the voltage levels, transformers enable safe and efficient transmission of electricity over long distances, as higher voltage levels result in lower current flow, which reduces energy loss due to resistance in conductors. The ability to modify voltage levels is crucial for distributing power across various electrical systems and ensuring that devices receive the appropriate voltage for their operation.