A breaker is filled with water at `4^@C`. at one time the temperature is increased by few degrees above `4^@C` and at another time it is decreased by a few degrees below `4^@C`. One shall observe that

Options

A. The level remains constant in each case
B. In first case water flows while in second case its level comes down
C. In second case water overflows while in first case it comes down
D. water overflows in both cases

Answer

To solve the problem, we need to analyze the behavior of water at different temperatures, particularly around the temperature of 4°C, which is known for its anomalous expansion properties.

### Step-by-Step Solution:

1. **Understanding the Anomalous Expansion of Water**:
Water exhibits a unique property where it reaches its maximum density at 4°C. Below this temperature, water expands as it cools, and above this temperature, it expands as it warms. This means that water behaves differently when heated or cooled around this critical temperature.

2. **Initial Condition**:
We start with a beaker filled with water at 4°C. At this temperature, the water has its minimum specific volume (maximum density).

3. **Increasing Temperature Above 4°C**:
When the temperature of the water is increased by a few degrees above 4°C (for example, to 6°C), the water expands. Since the mass of the water remains constant, the volume of the water increases. This means that if the beaker is filled to the brim, the water will overflow.

4. **Decreasing Temperature Below 4°C**:
Now, if we decrease the temperature of the water by a few degrees below 4°C (for example, to 2°C), the water also expands. Even though we are cooling the water, it expands as it goes from 4°C to lower temperatures. Thus, the volume again increases, leading to another potential overflow.

5. **Conclusion**:
In both scenarios—when the temperature is increased above 4°C and when it is decreased below 4°C—the volume of water increases. Therefore, in both cases, the water will overflow from the beaker.

### Final Observation:
Water will overflow in both cases when the temperature is changed from 4°C to either above or below it.