The hottest zone in the candle flame is the

Options

A. non-luminous zone
B. luminous zone
C. invisible zone
D. all zones are equally hot.

Explanation

**Step-by-Step Solution:**

1. **Understanding Candle Flame Zones**: A candle flame consists of different zones, each with varying temperatures and combustion characteristics. The main zones are the non-luminous zone, luminous zone, and the dark zone.

2. **Identifying the Hottest Zone**: The hottest zone in a candle flame is known as the non-luminous zone. This zone is characterized by complete combustion of the wax (fuel) with oxygen.

3. **Reason for High Temperature**: The non-luminous zone has an excess supply of oxygen, which allows for complete combustion. This results in a higher temperature compared to other zones.

4. **Color of the Hottest Zone**: The non-luminous zone is typically blue in color, indicating that the combustion is efficient and complete.

5. **Comparison with Other Zones**:
- **Luminous Zone**: This zone is where partial combustion occurs, leading to a moderate temperature and a yellowish flame.
- **Dark Zone (Invisible Zone)**: This zone has no supply of oxygen and is the least hot, often referred to as the dark zone.

6. **Conclusion**: Based on the characteristics of each zone, the hottest zone in the candle flame is the non-luminous zone.

**Final Answer**: The hottest zone in the candle flame is the **non-luminous zone**.

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