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प्रश्न
How do fishes survive in frozen lakes?
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उत्तर
Fishes survive in pond even when the atmospheric temperature is below 0°C. It is because of anomalous expansion of water. When the temperature falls below 0°C water changes into ice and rises to the top and ice being poor conductor of heat helps to keep water below it at 4°C and fish can live in pond water.
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संबंधित प्रश्न
A calorimeter contains 50 g of water at 50°C. The temperature falls to 45°C in 10 minutes. When the calorimeter contains 100 g of water at 50°C, it takes 18 minutes for the temperature to become 45°C. Find the water equivalent of the calorimeter.
Draw a graph to show the variation in density of water with temperature in the range from 0°C to 10°C.
Explain the following
A hollow glass sphere which floats with its entire volume submerged in water at 4°C, sinks when water is heated above 4°C.
Explain why do vegetables and fruits get damaged during severe frost?
A deep pond of water has its top layer frozen. What will be the likely temperature of water layer at the bottom of the pond?
Study the following diagrams and write down your observations.
What will be the approximate temperature of water in the lake shown in the following diagram?
(i) At X, and
(ii) At Y?
_______ apparatus is used to study the anomalous behaviour of water.
Match the columns:
| Column ‘A’ | Column ‘B’ |
| The density of water is maximum at | (a) 0°C |
| (b) 4°C | |
| (c) 100°C |
