Statement-I : Buta`-1,3-`diene is less stable than Penta`-1,4-`do,eme, ltbr. Because
Statement-II : Buta`-1,3-`diene has greater number of reasonating structures and delocallsed electron cloud.

Answer

To analyze the stability of buta-1,3-diene compared to penta-1,4-diene, we will evaluate both statements provided in the question.

### Step-by-Step Solution:

1. **Identify the Structures**:
- Buta-1,3-diene (C4H6) has the structure:
```
H2C=CH-CH=CH2
```
- Penta-1,4-diene (C5H8) has the structure:
```
H2C=CH-CH2-CH=CH2
```

2. **Analyze Conjugation and Resonance**:
- Buta-1,3-diene has two double bonds that are conjugated. This means that the double bonds are separated by a single bond, allowing for resonance.
- Penta-1,4-diene, however, has its double bonds separated by two single bonds, which does not allow for resonance between the double bonds.

3. **Draw Resonance Structures for Buta-1,3-diene**:
- The resonance structures for buta-1,3-diene can be drawn by shifting the pi electrons:
- Structure 1:
```
H2C=CH-CH=CH2
```
- Structure 2:
```
H2C^(-)-CH^+=CH-CH2
```
- Structure 3:
```
H2C-CH^+=CH^(-)-CH2
```
- These structures show that the pi electrons are delocalized across the molecule, contributing to its stability.

4. **Stability Comparison**:
- The presence of multiple resonance structures in buta-1,3-diene indicates that it has a delocalized electron cloud, which stabilizes the molecule.
- Penta-1,4-diene lacks this resonance stabilization due to the absence of conjugation.

5. **Conclusion**:
- **Statement I**: Buta-1,3-diene is less stable than penta-1,4-diene. This statement is **incorrect**.
- **Statement II**: Buta-1,3-diene has a greater number of resonating structures and a delocalized electron cloud. This statement is **correct**.

### Final Answer:
- Statement I is incorrect, and Statement II is correct.