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Q8. When does a drought occur?, , Ans - If it does not rain in a region for a year or more..The soil, and water bodies continue to lose water by evaporation and, plants by transpiration. Since this lost water is not being, brought back by the rain, the soil becomes dry and the level of, water in ponds and wells of the region goes down and some of, them may even dry up. The ground water may also become, scarce. These kinds of situations may lead to drought.

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Q7. How are clouds formed?, , Ans - Evaporation takes place from all the open surfaces of, water. As a result, water vapour gets continuously gets added, to the air. As these vapours gets higher from the surface of the, earth, it gets cooler and cooler. At sufficient heights, the air, becomes so cool that water vapour present in it condenses to, form tiny drops of water called water droplets. These tiny, droplets of water that remain suspended and floating in air, appear to us as clouds.

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Q6. To clean their spectacles, people often breathe out ng, glasses to make them wet. Explain why the glasses become, wet?, , Ans - The warm air we breathe out contains carbon dioxide, and moisture (Water vapour). The moisture condenses on to, the surface of glass to make the glass wet.

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Q5. Take out a cooled bottle of water from refrigerator and, keep it on a table. Afté# some time, you notice a puddle of, water around it. Why?, , Ans - It is due to condensation of water vapour present in air., Air contains water in the form of vapours, when it come in, contact with the cool water bottle, it gets condensed and, appear as water droplets.

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Q4. Suppose you want to dry your school uniform quickly., Would spreading it near an anghiti or heater help? If yes, how?, , Ans — Yes, the rate of evaporation increases with increase in, temperature. So, the rate of evaporation will be higher near an, anghiti or heater and the school uniform will dry up quickly.