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प्रश्न
Why do the farmers fill their fields with water on a cold winter night?
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उत्तर
In the absence of water, if on a cold winter night the atmospheric temperature falls below 0oC,
the water in the fine capillaries of plant will freeze, so the veins will burst due to the increase in
the volume of water on freezing. As a result, plants will die and the crop will be destroyed. In
order to save the crop on such cold nights, farmers fill their fields with water because water has
high specific heat capacity, so it does not allow the temperature in the surrounding area of plants
to fall up to 0oC.
संबंधित प्रश्न
What do you understand by the following statements:
The heat capacity of the body is 60JK-1.
State three ways to minimize the global warming.
Give one example where high specific heat capacity of water is used as cooling.
Solve the following problem.
Specific latent heat of vaporization of water is 2.26 × 106 J/kg. Calculate the energy needed to change 5.0 g of water into steam at 100 ºC.
All metals have the same specific heat capacity.
The cold object the hot object enclosed in one box of heat-resistant material.
- What changes will occur in the two objects when temperature flows from those objects?
- Which principle can show that the energy exchange takes place between two objects only when kept in isolated system?
Numerical Problem.
How much heat energy is required to change 2 kg of ice at 0°C into water at 20°C? (Specific latent heat of fusion of water = 3,34,000 J/kg, Specific heat capacity of water = 4200 JKg–1K–1).
When a uniform rod is heated, which of the following quantity of the rod will increase
Two uniform brass rods A and B of length land 2l and radii 2r and r respectively are heated to the same temperature. The ratio of the increase in the volume ofB to that of A is ____________.
Match the following
| 1. | Specific heat capacity | a. | Dewar bottle |
| 2. | Calorimeter | b. | Lavoisier and Simon |
| 3. | Vacuum flask | c. | J Kg-1 K-1 |
| 4. | Ice – calorimeter | d. | Heat capacity |
