Unburnt carbon particles are present in the

Options

A. blue zone
B. dark inner zone
C. luminous zone
D. non-luminous zone

Answer

To solve the question "Unburnt carbon particles are present in the", we need to analyze the different zones of a flame and identify where unburnt carbon particles are typically found.

### Step-by-Step Solution:

1. **Understanding Flame Zones**: A flame can be divided into different zones based on temperature and combustion characteristics. The main zones are:
- Luminous zone
- Non-luminous zone
- Dark inner zone
- Value zone (not commonly referred to in standard flame descriptions)

2. **Identifying the Luminous Zone**: The luminous zone is the part of the flame that is bright and emits light. This brightness is due to the presence of unburnt carbon particles that are heated to incandescence.

3. **Recognizing Unburnt Carbon**: Unburnt carbon particles are formed when there is incomplete combustion. This typically occurs in the luminous zone where there is a sufficient amount of fuel but not enough oxygen for complete combustion.

4. **Conclusion**: Since the question asks where unburnt carbon particles are present, we conclude that they are found in the luminous zone of a flame.

5. **Final Answer**: Therefore, the correct answer is **option 3: luminous zone**.