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प्रश्न
For the same mass of ice and ice-cold water, why does ice produce more cooling than ice-cold water?
उत्तर
For the same mass of ice and ice-cold water, due to the absorption of latent heat by the ice, the ice produces more cooling than ice-cold water.
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संबंधित प्रश्न
State two characteristics of a good thermion emitter.
State two factors upon which the rate of emission of thermions depends.
Write the approximate value of specific latent heat of ice.
What is meant by latent heat? How will the state of matter transform if latent heat is given off?
Answer the following:
Explain the role of latent heat in the change of state of a substance.
Liquid ammonia is used in ice factory for making ice from water. If water at 20°C is to be converted into 2 kg ice at 0°C, how many grams of ammonia are to be evaporated? (Given: The latent heat of vaporization of ammonia = 341 cal/g)
Explain the following temperature Vs. time graph:
Define the following terms:
(i) Latent heat,
(ii) Latent heat of fusion of ice.
What is the name given to the energy absorbed during a phase change?
Define specific latent heat of vaporization of a substance.
The specific latent heat of vaporisation of steam is 2260 J/g. Comment on this.
Why do we feel much comfortable when we sit under a moving fan especially when our body is sweating?
Match the columns.
| Column A | Column B |
| 1) Absolute humidity | a) J or cal |
| 2) Latent heat | b) J/kg °C |
| 3) Specific heat capacity | c) kJ/kg |
| 4) Heat | d) no unit |
| e) kg/m3 |
Write the name.
Products obtained when sugar is heated.
Write the name.
The phase in which solid substances are converted into liquid.
1 kg of dry air at a temperature of 40 °C can hold a maximum of 49 g of water vapour.
600 g of copper at 50°C is mixed with lOOOg water at 20°C. Find the final temperature of the mixture. The specific heat capacity of copper is 0.4 Jg-1°C-1 and that of water is 4.2 Jg-1°C-1
Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C. (Specific latent heat of ice = 336 Jg-1, specific heat capacity of water = 4.2 Jg-1 °C-1)
