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प्रश्न
Give two applications of evaporation.
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उत्तर
Two applications of evaporation:
- When we sprinkle water on the roads in the summer evening, water evaporates by taking heat from the road and produces coolness in the surroundings and it becomes pleasant.
- After taking a bath in summer when we come out of the water, water evaporates taking heat from our body. The temperature of body falls and we feel refreshed.
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संबंधित प्रश्न
Why does a desert cooler cool better on a hot dry day?
What is evaporation?
Water in a dish evaporates faster than in a bottle. Give reason.
Define the following terms Condensation
How does the water kept in an earthen pot (matka) become cold during summer ?
Why does our palm feel cold when we put some acetone (or perfume) on it ?
The scientists now say that there are actually five states of matter A, B, C, D and E. The state A has a fixed volume but no fixed shape. The state B can be compressed very easily by applying pressure and state C has a fixed shape as well as a fixed volume. The state D is a mixture of free electrons and ions whereas state E is named after an Indian scientist and a famous physicist.
- Name the physical states (i) A (ii) B (iii) C (iv) D, and (v) E
- Name one substance belonging to state C which can directly change into vapours on heating. What is this process known as ?
- Name one substance which normally belongs to state B but whose solid form changes directly into gaseous state.
- Name the most common substance belonging to state A.
- Which state of matter makes the sun and other stars to glow ?
Comment on the following statements:
Rate of evaporation of an aqueous solution decreases with increase in humidity.
The rate of evaporation ______ with rising temperature.
The rate of evaporation is more when the surface area is greater.
