What device changes direct current (DC) to alternating current (AC)?

The device that changes direct current (DC) to alternating current (AC) is a converter. Converters play a critical role in electrical engineering and power systems by enabling the transformation of electrical current types to meet various needs. In many modern applications, including consumer electronics and renewable energy systems, the ability to switch between AC and DC is essential.

Converters come in different forms, such as inverters, which specifically convert DC to AC. This is particularly important in scenarios like solar energy systems, where solar panels generate DC electricity, and an inverter is necessary to transform that energy into AC for home use or feeding into the electrical grid.

The other options do not serve this function. A transmitter is used for sending signals, not for changing current types. An ampere is a unit of measurement for electric current and does not perform any conversion. A resistor is a component used to limit current flow; it does not change the nature of the current itself. Thus, converter is clearly the appropriate choice for the function of changing DC to AC.