How is the video signal modulated compared to the audio signal?

The modulation of video and audio signals plays a crucial role in how these signals are transmitted and received effectively. In the correct choice, the video signal is modulated using phase modulation, while the audio signal typically employs amplitude modulation.

Phase modulation for video signals allows for the representation of a wide range of color and luminance information in a compact format. This is particularly important for video because it needs to convey a lot of visual detail and dynamic range to accurately represent moving images. Phase modulation can handle the rapid changes in the video signal more effectively, maintaining a higher fidelity in the representation of the image.

On the other hand, audio signals predominantly use amplitude modulation due to the nature of sound information, which is effectively captured through variations in amplitude that correspond to the loudness of the sound. Amplitude modulation allows audio signals to reproduce a broad spectrum of sounds while being simpler in terms of bandwidth requirements compared to phase modulation.

This differentiation in modulation techniques directly relates to the demands of transmitting these different types of signals—video requires a method that can handle rapid changes and detail, while audio focuses on accurately conveying sound levels. Understanding these modulation techniques is fundamental for communication systems, media broadcasting, and signal processing.