Advertisements
Advertisements
Question
Why is cooling produced on evaporation of a liquid?
Solution
For evaporation of a liquid, it requires HEAT. This heat is taken from the surroundings like body or palm or forehead or finger and its temperature falls and we feel cool.
APPEARS IN
RELATED QUESTIONS
Why does a desert cooler cool better on a hot dry day?
Why does our palm feel cold when we put some acetone or petrol or perfume on it?
Wet clothes dry more quickly on a warm dry day than on a cold humid day. Explain.
Water in a dish evaporates faster than in a bottle. Give reason.
A patient suffering from high fever is advised to put wet clot strips on his forehead. Why?
Would you cool a bucket of water more quickly by placing it on ice or by placing ice in it ? Give reasons for your answer.
Why does all the water of the earth not get evaporated during hot summer days ?
How can the evaporation of a liquid be made faster ?
What is evaporation ? State the various factors which affect evaporation.
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 ?
