If the tension in the string of a guitar is increased keeping other factors unchanged, then which of the following statements is/are incorrect?
I. The sound produced is louder.
II. The sound produced has higher pitch.
III. The sound produced has lower pitch.

Options

A. II only
B. I only
C. I and III only
D. I, II and III

Explanation

To solve the question regarding the effect of increased tension in a guitar string on the sound produced, we can analyze each statement provided:

1. **Understanding the relationship between tension and sound:**
- The frequency of the sound produced by a vibrating string is determined by the tension in the string, the length of the string, and the mass per unit length of the string.
- When the tension in the string increases, the frequency of the sound produced also increases. This is because the speed of the wave on the string is proportional to the square root of the tension.

2. **Analyzing the statements:**
- **Statement I: The sound produced is louder.**
- This statement is not necessarily true. While increased tension can lead to a stronger vibration, which may increase the amplitude of the sound wave (making it louder), this is not guaranteed. The loudness also depends on other factors such as the material of the string and how it is played.
- **Conclusion:** This statement can be considered incorrect.

- **Statement II: The sound produced has higher pitch.**
- This statement is true. As the tension increases, the frequency of the sound produced increases, which results in a higher pitch.
- **Conclusion:** This statement is correct.

- **Statement III: The sound produced has lower pitch.**
- This statement is false. Since we established that increasing tension leads to an increase in frequency, it follows that the pitch will also increase, not decrease.
- **Conclusion:** This statement is incorrect.

3. **Final assessment:**
- The incorrect statements are I and III. Therefore, the answer to the question is that statements I and III are incorrect.

### Summary of the Solution:
- **Statement I** (The sound produced is louder) is incorrect.
- **Statement II** (The sound produced has higher pitch) is correct.
- **Statement III** (The sound produced has lower pitch) is incorrect.