In T.V., the picture signal is

Question

In T.V., the picture signal is

1. A. Amplitude modulated and at the low-frequency end of each channel allocation (Correct answer)
2. B. Frequency modulated and at the low-frequency end of each channel allocation
3. C. Amplitude modulated and at the high frequency end of each channel allocation
4. D. None of above

Correct Answer

Option A — Amplitude modulated and at the low-frequency end of each channel allocation

Detailed Solution & Explanation

The correct answer is Amplitude modulated and at the low-frequency end of each channel allocation.

Key Points

• The picture (video) signal in television is amplitude modulated, and it is placed at the low-frequency end of the channel allocated to that station.
• The sound signal is frequency modulated and sits at the upper end of the same channel, keeping the two carriers well separated.
• AM is chosen for video because the video baseband is very wide, and frequency modulation of such a signal would demand far more bandwidth than a channel can provide.

Additional Information

• A standard analogue TV channel occupies 6, 7 or 8 MHz depending on the broadcasting system in use.
• The video carrier is transmitted using vestigial sideband (VSB) modulation, which suppresses most of one sideband to conserve bandwidth while preserving the low-frequency picture content.