Which device is used to convert direct current (DC) to alternating current (AC)?

The device that converts direct current (DC) to alternating current (AC) is an inverter. Inverters are essential components in various applications, particularly in renewable energy systems, such as solar power systems, where the direct current generated by solar panels needs to be converted into alternating current to be used in homes or fed into the electrical grid.

Inverters work by switching the direction of the current back and forth, effectively creating an AC waveform from a steady DC source. This function is vital for making the energy generated from DC sources compatible with standard AC electrical systems, which are predominantly used for power distribution.

Transformers, while essential for voltage transformation in AC circuits, do not operate with DC input. Resistors and capacitors serve different functions in electrical circuits; resistors limit current flow, and capacitors store electrical energy temporarily, but neither is capable of performing the conversion from DC to AC. Therefore, the specific role of inverters in this conversion process makes them the correct choice in this context.