In T.V. broadcasting both picture and sound are transmitted simultaneously. In this

Options

A. audio signal is frequency modulated and video signal is amplitude modulated
B. both audio and video signals are frequency modulated
C. audio signal is amplitude modulated and video signal is frequency modulated
D. both audio and video signals are amplitude modulated

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question states that in TV broadcasting, both picture (video) and sound (audio) are transmitted simultaneously. We need to identify the modulation techniques used for each signal.

2. **Identifying the Signals**: In TV broadcasting, there are two main types of signals:
- **Audio Signal**: This represents the sound.
- **Video Signal**: This represents the picture.

3. **Modulation Techniques**: Different modulation techniques are used for audio and video signals to prevent interference and to accommodate their different bandwidth requirements.
- **Frequency Modulation (FM)**: This technique is typically used for audio signals.
- **Amplitude Modulation (AM)**: This technique is typically used for video signals.

4. **Reason for Different Modulations**:
- **Interference Prevention**: If the same modulation technique is used for both signals, there is a risk of them interfering with each other, leading to a loss of quality.
- **Bandwidth Requirements**: Audio signals require a lower bandwidth (around 2 MHz), while video signals require a larger bandwidth (around 4 MHz). Using different modulation techniques allows for the effective use of bandwidth.

5. **Conclusion**: Based on the above analysis, we conclude that:
- The audio signal is **Frequency Modulated (FM)**.
- The video signal is **Amplitude Modulated (AM)**.

6. **Final Answer**: Therefore, the correct option is that the audio signal is frequency modulated and the video signal is amplitude modulated.