What does a transformer do to voltage levels in alternating current circuits?

A transformer is a device specifically designed to transfer electrical energy between two or more circuits through electromagnetic induction. Its primary function is to change voltage levels in alternating current (AC) circuits.

When an alternating current flows through the primary winding of a transformer, it creates a magnetic field that induces a voltage in the secondary winding. Depending on the configuration of the windings—the number of coils in the primary compared to the secondary—the transformer can either step up (increase) or step down (decrease) the voltage.

If the primary winding has more turns than the secondary, the voltage will be reduced, effectively stepping it down. Conversely, if the secondary winding has more turns, the voltage will increase, stepping it up. This ability to transform voltage levels is essential in power distribution systems, allowing for efficient transmission of electrical energy over long distances.

The other options describe different electrical functions: generating power, measuring current, and storing energy, but they do not pertain to the specific function of transforming voltage levels in AC circuits, which is the role of a transformer.