When generating an AC signal, what does the transformer do to the voltage?

The transformer is used to change the voltage level of an alternating current (AC) signal while maintaining the overall power level in the system, which is why the correct answer emphasizes that it increases voltage without altering power.

When an ideal transformer operates, it operates under the principle of magnetic induction, where the input voltage (primary side) is transformed to a different output voltage (secondary side) depending on the turns ratio of the windings. If there are more turns on the secondary side than on the primary side, the transformer will step up the voltage, resulting in a higher voltage output. Consequently, according to the law of conservation of energy, the power (voltage times current) remains constant assuming there are no losses in the transformer. Therefore, if the voltage increases, the current must decrease proportionally to maintain the same power level.

This principle is pivotal because it allows electrical systems to transmit power efficiently over long distances by stepping up the voltage and subsequently stepping it back down for use. The other options suggest changes to current or describe actions that transformers do not perform, such as altering power levels significantly, converting AC to DC, or reducing voltage without compensating current appropriately. Only the selected answer accurately reflects the function of a transformer in AC signal generation.