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प्रश्न
Give reasons:
Water pipes burst in severe winters.
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उत्तर
During severe winters when the temperature starts falling below 4°C, water in pipelines expands (due to the property of anomalous expansion of water), and it exerts large pressure on the pipes, causing them to burst.
संबंधित प्रश्न
On what basis and how will you determine whether air is saturated with vapour or not?
Consider the situation of the previous problem. Assume that the temperature of the water at the bottom of the lake remains constant at 4°C as the ice forms on the surface (the heat required to maintain the temperature of the bottom layer may come from the bed of the lake). The depth of the lake is 1.0 m. Show that the thickness of the ice formed attains a steady state maximum value. Find this value. The thermal conductivity of water = 0.50 W m−1°C−1. Take other relevant data from the previous problem.
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.
What do you understand by the anomalous expansion of water?
Draw a graph between volume and temperature, when 5 cm3 of ice at -10°C is heated to form water at +10°C.
How do fishes survive in frozen lakes?
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?
The following figure shows a metal cylinder, containing boiling water. One half side A is polished and another half, B is painted black. Two thin metal sheets X and Y are painted black and have one rubber stopper fixed with wax on each sheet. These sheets are equidistant from the boiling water (container A, B) as shown in the diagram. What would you expect to happen after a few minutes? Give a reason for your answer.
What is the criterion of choosing the two metals for a bimetal strip?
Observe the given graph and answer the following questions:
- Name the process represented in the figure.
- At what temperature does this process take place?
_______ apparatus is used to study the anomalous behaviour of water.
Write scientific reason.
Fish can survive even in frozen ponds in cold regions.
Observe the following diagram and write the answers to the questions given below.
- Which process does the graph represent?
- What is the range of temperature responsible for the behaviour?
Observe the given picture and answer the following questions.
- Which property do you understand in this picture?
- What is the temperature of the water at the surface?
- What is the temperature below the layer of ice on the surface?
