What is the function of a transformer in electrical systems?

The function of a transformer in electrical systems is to change alternating current (AC) from one voltage level to another voltage level. This is pivotal in the distribution of electrical power, where it is often necessary to increase or decrease voltage levels to ensure efficient transmission over long distances, while also enabling safe usage in residential and commercial settings.

Transformers operate based on the principle of electromagnetic induction and are designed to transfer electrical energy between two or more circuits. They can step up (increase) voltage for efficient transmission or step down (decrease) voltage for safe consumer usage, such as in homes. This capability is essential in preventing energy loss and ensuring that the electrical supply is appropriately matched to devices and appliances.

The other options do not accurately reflect the function of a transformer in electrical systems. For instance, converting direct current (DC) to alternating current (AC) is the role of an inverter, not a transformer. Increasing the speed of electrical devices is related to the characteristics of motors or other components, not transformers. Lastly, storing electrical energy for later use pertains to batteries or capacitors, which fulfill a different function than that of a transformer.