Statement-1 : Explosions on other planets are not heard on earth
Statement-2 : To hear distinct beats, difference in frequencies of two sources should be less than 10.

Options

A. Statement-1 is true, Statement-2 is true , Statement-2 is correct explanation for Statement-2
B. Statement-1 is true,Statement-2 is true , Statement-2 is NOT a correct explanation for Statement-2
C. Statement-1 is true, Statement-2 is false
D. Statement-1 is false, Statement-2 is true

Answer

To analyze the given statements, we will break down each statement and evaluate their correctness step by step.

### Step 1: Evaluate Statement 1
**Statement 1**: "Explosions on other planets are not heard on Earth."

1. **Understanding Sound Propagation**: Sound is a mechanical wave that requires a medium (like air, water, or solid materials) to travel. In space, beyond Earth’s atmosphere, there is a vacuum where there is no medium for sound to propagate.

2. **Conclusion for Statement 1**: Since explosions on other planets occur in space, and there is no medium for sound to travel through, these explosions cannot be heard on Earth. Therefore, Statement 1 is **correct**.

### Step 2: Evaluate Statement 2
**Statement 2**: "To hear distinct beats, the difference in frequencies of two sources should be less than 10."

1. **Understanding Beats**: Beats occur when two sound waves of slightly different frequencies interfere with each other. The beat frequency is the absolute difference between the two frequencies.

2. **Condition for Distinct Beats**: To perceive distinct beats, the difference in frequency (Δf) must be small enough. If the difference is too large, the beats will be too fast, and we won't be able to distinguish them.

3. **Threshold for Distinct Beats**: Research indicates that for distinct beats to be heard, the difference in frequencies should generally be less than about 10 Hz. If the difference is greater than or equal to 10 Hz, the beats will be too rapid to distinguish clearly.

4. **Conclusion for Statement 2**: Therefore, Statement 2 is also **correct**.

### Step 3: Relationship Between the Statements
1. **Independence of Statements**: While both statements are correct, Statement 2 does not explain Statement 1. The reason explosions on other planets cannot be heard on Earth is due to the lack of a medium for sound propagation, which is unrelated to the conditions for hearing distinct beats.

### Final Conclusion
- **Statement 1**: True
- **Statement 2**: True
- **Explanation**: Statement 2 is not the correct explanation for Statement 1.