Q. Threshold limit value (TLV) i.e., the maximum permissible safe limit of phosgene gas which Hitler used to use to kill his enemies in 'gas chamber' is about __________ ppm.

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Q. Photochemical smog is formed from automobile exhaust

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Q. Reinglemann chart is used for the measurement of the

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Q. Disinfection of water is done to remove

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Q. Which of the following fine dust removal equipments is the most efficient ?

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Q. The weakest sound that can be heard by a person in a quiet environment is equivalent to __________ decibel.

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Q. Inorganic impurities causing water pollution is

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Q. The main type of sludge gas evolved during sewage treatment in Imhoff tank is

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Q. From pollution control point of view, the maximum permissible concentration of sulphur dioxide in atmospheric air is about __________ ppm.

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Q. The pH value of oxidised sewage is about

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Q. Threshold limit value (TLV) means maximum permissible/acceptable concentration. TLV of phosgene in air is about __________ ppm (parts per million).

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Q. The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the

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Q. Biological oxidation ponds remove organic matters present in the polluted water by

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Q. Which of the following is an adsorbant for removal of nitrogen oxides from gas/air ?

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Q. Out of the following, TLV of __________ is the minimum (about 0.02 ppm).

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Q. Fluorosis is caused due to the presence of excessive amount of __________ in drinking water.

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Q. Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes

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Q. Pick out the wrong statement.

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Q. The pH value of potable water should be between

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Q. Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.

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