In NTSC, the 4:3 aspect ratio describes which of the following?

• A. Governs the frame rate
• B. Defines the width-to-height ratio
• C. Defines the color encoding
• D. Determines display resolution

Answer: (B)

The thing being tested is how the image’s shape is described. The 4:3 notation in NTSC specifies the width-to-height proportion of the picture frame—four units wide for every three units tall. This describes the image’s aspect ratio, not how many frames are shown per second, how color is encoded, or the exact display resolution. Frame rate in NTSC refers to about 29.97 interlaced frames per second, color encoding refers to how color information is carried (such as NTSC’s YIQ), and resolution relates to how many pixels or lines are used, which isn’t fixed in the old analog NTSC system. So, the 4:3 aspect ratio best describes the width-to-height ratio.