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प्रश्न
Give reason.
A dry handkerchief gets wet at once on dipping in water, but it takes longer for a wet handkerchief to dry.
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उत्तर
A dry handkerchief gets wet at once because it quickly absorbs the water in which it is dipped. However, it takes longer for a wet handkerchief to dry because the water needs to evaporate from the handkerchief. Evaporation is a slow process that is dependent on other factors as well, like relative humidity.
संबंधित प्रश्न
Fill in the blank
Burning of fuel is a _______ change.
State whether the following is physical or chemical changes.
passing electric current through a heater rod —
Tick (√) the correct alternative from the choice given for the following statement
When sugar is heated, its colour changes into
True or false?
In a chemical change, rearrangement of molecules and atoms involves some energy changes.
Fill in the blank
An earthquake is a _______ change.
Distinguish between the following.
Natural change and man-made change
Fill in the blanks with the appropriate words of the statement given below:
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- What can you say about the quality of water that is obtained in the beaker?
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