Which device is used to convert DC back to AC current?

The correct answer is an inverter. An inverter is specifically designed to convert direct current (DC) into alternating current (AC). This is crucial in various applications, such as in solar power systems. Solar panels generate electricity in DC form, and inverters are used to convert this electricity into AC so it can be used in homes and businesses, or integrated into the grid, which predominantly operates on AC.

Understanding the role of an inverter is essential when working with renewable energy systems, as they ensure that the energy produced is usable for household appliances and compatible with the electrical infrastructure.

A rectifier, in contrast, performs the opposite function; it converts AC to DC. A transformer is used to change the voltage levels in AC systems but does not convert between AC and DC. An amplifier is used to increase the power of a signal, again unrelated to the conversion between AC and DC.