Amplitude modulation index `mu` determines

Options

A. The quality of received signal
B. The quality of transmitted signal
C. The quality of carrier wave
D. Both (1) and (3)

Answer

To solve the question regarding the amplitude modulation index `mu`, we will analyze the concept of modulation index and its significance in amplitude modulation.

### Step-by-Step Solution:

1. **Understanding Amplitude Modulation Index (Mu)**:
- The amplitude modulation index, denoted as `mu`, is defined as the ratio of the change in amplitude of the carrier wave to the amplitude of the unmodulated carrier wave.
- Mathematically, it can be expressed as:
\[ \mu = \frac{\Delta A_c}{A_c} \]
where \( \Delta A_c \) is the change in amplitude of the carrier wave, and \( A_c \) is the amplitude of the unmodulated carrier wave.

2. **Physical Significance of Modulation Index**:
- The modulation index indicates how much the amplitude of the carrier wave varies due to the modulation process.
- A higher value of `mu` indicates a greater variation in the amplitude of the carrier wave, which generally leads to a stronger and clearer transmitted signal.

3. **Quality of the Signal**:
- The modulation index directly affects the quality of the transmitted signal. A low `mu` value means that the amplitude variations are small, which can lead to a weaker signal and poorer quality.
- Conversely, a higher `mu` value suggests that the signal is stronger and of better quality.

4. **Conclusion**:
- Based on the analysis, the amplitude modulation index `mu` determines the strength and quality of the transmitted signal. Therefore, the correct answer to the question is that it determines the quality of the transmitted signal.

### Final Answer:
The amplitude modulation index `mu` determines the quality of the transmitted signal.