D/A conversion is described as what?

• A. An electronic circuit that converts a digital signal to an analogue signal
• B. An antenna that radiates digital data
• C. A device that samples an analogue signal
• D. A device that compresses audio into mp3

Answer: (A)

Digital-to-analog conversion is the process of turning discrete digital values into a continuous analogue signal. A D/A converter takes a digital code and outputs a corresponding analogue voltage or current, producing a waveform that can be used by audio amplifiers or other analogue devices. This matches the description of an electronic circuit that converts a digital signal to an analogue signal. The other ideas describe different concepts: an antenna radiates digital data is wireless transmission, sampling an analogue signal is part of analogue-to-digital conversion, and compressing audio into mp3 is data compression. In practice, the analogue output can appear as a staircase waveform unless filtered to smooth it into a continuous signal.