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A group of 20 students of Class XII went to a nearby village. They observed that there is a lot of difference in the environment of rural and urban area. In urban area, there is a lot of pollution. Peoples are suffering from cough, typhoid, and skin diseases but in rural area people are healthy. There are a large number of trees in rural area therefore, environment is clean. (i) What are the main reasons of air pollution? (ii) What are primary and secondary pollutants? (iii) Name two water borne diseases. (iv) What is global warming? (v) Why is it advisable to switch off engine of vehicle at red light? (vi) What is photochemical smog? |
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Answer» i) the main reasons for pollution are increasing of exhaust gas from vehicles is mainly made of carbon di oxide and nitrogen as we know both the gases are harmful toxic gas from industries are RELEASED into air without proper treatment this reacts with water vapour to form acid rain ii) primary pollutants: these are EMITTED directly from a source hence they are called primary pollutants secondary pollutants : these are not directly produced but are FORMED when primary pollutants react with environment iii) two water BORNE diseases are malaria and cholera iv) global warming is the process when gases like CARBON DI OXIDE form a layer around earth and do not let the heat escape as a result the temperature INCREASES and calamities occur v) it is advisable to switch off engine at red light as it reduces the pollutants and also saves petrol vi) photo chemical smog means haze created in the atmosphere accompanied by high levels of ozone and nitrogen oxide , caused by action of sunlight on pollutants |
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