How ac voltage is superimposed on dc voltage?

AC voltage can be superimposed on DC voltage by adding the AC signal to the DC level in a circuit. This is often achieved using capacitive or resistive coupling, where the AC waveform rides on top of the constant DC voltage. The resulting waveform is a combination of the steady DC component and the fluctuating AC component, allowing for the transmission of both types of signals simultaneously. This technique is commonly used in various electronic applications, such as in modulation and signal processing.