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प्रश्न
Assertion (A): If BOD level of water in a reservoir is less than 5 ppm it is highly polluted.
Reason (R): High biological oxygen demand means low activity of bacteria in water.
पर्याय
Both A and R are correct and R is the correct explanation of A.
Both A and R are correct but R is not the correct explanation of A.
Both A and R are not correct.
A is not correct but R is correct.
उत्तर
Both A and R are not correct.
Explanation:
Since the amount of oxygen required by bacteria to breakdown the organic matter present in a certain volume of a sample of water, is called BOD i.e., Biochemical Oxygen Demand. If the BOD of the water is < 5 ppm then it is clean but if it increases then the water pollution increases.
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संबंधित प्रश्न
What is the main source of pollution?
The disposal of urban waste has become a serious concern for the local authorities. Analyze the statement with suitable examples.
Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be ______.
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Dissolved oxygen in water is very important for aquatic life. What processes are responsible for the reduction of dissolved oxygen in water?
What are the sources of dissolved oxygen in water?
What is the importance of measuring BOD of a water body?
Oxidation of sulphur dioxide into sulphur trioxide in the absence of a catalyst is a slow process but this oxidation occurs easily in the atmosphere. Explain how does this happen. Give chemical reactions for the conversion of SO2 into SO3.
Match the activity given in Column I with the type of pollution created by it given in Column II.
| Column I (Activity) | Column II (Effect) | ||
| (i) | Releasing gases to the atmosphere after burning waste material containing sulphur. |
(a) | Water pollution |
| (ii) | Using carbamates as pesticides | (b) | Photochemical smog, damage to plant life, corrosion to building material, induce breathing problems, water pollution |
| (iii) | Using synthetic detergents for washing clothes |
(c) | Damaging ozone laye |
| (iv) | Releasing gases produced by automobiles and factories in the atmosphere. |
(d) | May cause nerve diseases in human. |
| (v) | Using chlorofluorocarbon compounds for cleaning computer parts |
(e) | Classical smog, acid rain, water pollution, induce breathing problems, damage to buildings, corrosion of metals. |
Which of the following is/are the causes of pollution in Yamuna?
- Industrial pollution from Kanpur.
- Domestic waste from Delhi.
- Extraction of water by Haryana and Uttar Pradesh for irrigation.
