Place a piece of burning charcoal on an iron plate and cover it with a plastic jar. The charcoal stops burning because

Options

A. its ignition temperature is lowered
B. supply of oxygen is cut off
C. it becomes cold after some time
D. none of the above.

Explanation

To solve the question "Place a piece of burning charcoal on an iron plate and cover it with a plastic jar. The charcoal stops burning because...", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Combustion**:
- Combustion is a chemical process where a substance reacts with oxygen to produce heat and light. For combustion to occur, three elements are necessary: fuel, oxygen, and heat (known as the fire triangle).

2. **Identifying the Scenario**:
- In this scenario, we have burning charcoal, which acts as the fuel. When we cover the burning charcoal with a plastic jar, we are enclosing it.

3. **Effect of Covering with a Jar**:
- When the charcoal is covered with a plastic jar, the supply of oxygen becomes limited. The jar prevents fresh air (which contains oxygen) from reaching the burning charcoal.

4. **Conclusion**:
- Since oxygen is essential for combustion, the lack of oxygen will cause the burning process to stop. Therefore, the charcoal stops burning because the oxygen supply is cut off.

5. **Selecting the Correct Option**:
- Among the options provided:
- 1. Ignition temperature is lowered.
- 2. Supply of Oxygen is cut off.
- 3. It becomes cold after some time.
- 4. None of the above.
- The correct answer is option 2: "Supply of Oxygen is cut off."

### Final Answer:
The charcoal stops burning because the supply of oxygen is cut off when it is covered with a plastic jar.

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