A beaker is completely filled with water at `4^(@)C.` It will overflow if

Options

A. heated above `4^(@)C`
B. cooled below `4^(@)C`
C. both heated and cooled above and below `4^(@)C` respectively
D. None of the above

Explanation

To solve the question, we need to understand the behavior of water at different temperatures, particularly around the temperature of 4°C, where its density is at a maximum.

### Step-by-Step Solution:

1. **Understanding Water Density at 4°C**:
- Water has a unique property where its density is highest at 4°C. At this temperature, the volume occupied by a given mass of water is at its minimum.

2. **Effect of Heating Water**:
- When water is heated above 4°C, its density decreases. Since the mass of water remains constant, a decrease in density leads to an increase in volume (using the relationship \( \text{Mass} = \text{Density} \times \text{Volume} \)).
- As the volume increases, the water will start to overflow from the beaker.

3. **Effect of Cooling Water**:
- Conversely, if the water is cooled below 4°C, the density also decreases. Again, with constant mass, a decrease in density results in an increase in volume.
- This increase in volume will also cause the water to overflow from the beaker.

4. **Conclusion**:
- Therefore, whether the water is heated above 4°C or cooled below 4°C, it will overflow from the beaker.
- The correct answer is option 3: "both heated and cooled above and below 4°C respectively."

### Final Answer:
The beaker will overflow if the water is either heated above 4°C or cooled below 4°C. Thus, the correct option is option 3.

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