A magician performed following act: He dipped Rs. 50 note in a 50% solution of alcohol in water and held it on the burning flame, but the note did not burn. The reason behind this is :

Options

A. The alcohol kept on dousing the fire
B. Air required for burning was not available
C. The Rs. 50 note failed to reach ignition temperature
D. The Rs. 50 note is fire proof

Explanation

To solve the question of why the Rs. 50 note did not burn when dipped in a 50% alcohol solution and held over a flame, we can break down the reasoning step by step.

### Step-by-Step Solution:

1. **Understanding the Components**:
- The magician used a solution that is 50% alcohol and 50% water. This means that half of the solution is water, which is crucial for our explanation.

2. **Dipping the Note**:
- The Rs. 50 note was dipped into this solution. When the note is submerged, it absorbs some of the liquid, which includes both alcohol and water.

3. **Presence of Water**:
- Water has a high specific heat capacity and can absorb a lot of heat before its temperature rises significantly. This means that when the note is held over the flame, the water present in the note will absorb heat.

4. **Insulating Effect**:
- The water forms a layer around the note, acting as an insulator. This layer prevents the temperature of the note from reaching its ignition temperature, which is the minimum temperature required for combustion to occur.

5. **Ignition Temperature**:
- For a material to catch fire, it must reach its ignition temperature. In this case, the presence of water keeps the temperature of the Rs. 50 note below this critical point, preventing it from burning.

6. **Conclusion**:
- As a result, despite being exposed to a flame, the Rs. 50 note does not burn because the water layer insulates it and prevents it from reaching the necessary temperature for combustion.

### Final Answer:
The Rs. 50 note did not burn because the water in the 50% alcohol solution insulated the note, preventing it from reaching its ignition temperature.

---