Q. The concentration of water vapour in troposphere, which depends upon the altitude & temperature varies in the range of zero to __________ percent.

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Q. The main industrial source of emission of hydrogen sulphide air pollutant is

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Q. Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances.

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Q. A shallow pond in which the sewage is retained and biologically treated is called

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Q. Which is the most practical and economical method for removal of suspended solid matter from polluted water ?

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Q. Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region called

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Q. Iron & manganese present in the polluted water is removed by

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Q. Water effluent generated in printing industry is decolourised by

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Q. Oil and grease present in an emulsified state in waste water discharged from industries can be removed by

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Q. The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated.

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Q. Particles having diameter greater than 75 μm (micrometer = 10⁻⁶ mm) are called

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Q. Which of the following is the most severe air pollutant ?

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Q. Presence of bacteria in potable (drinking) water causes

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Q. Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?

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Q. COD of raw municipal sewage may be in the range of about __________ mg/litre.

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Q. Maximum permissible turbidity in potable water is __________ ppm.

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Q. Presence of __________ hardness is responsible for the temporary hardness in water.

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Q. Dose of chlorine for disinfection of water is about __________ mg/litre of water.

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Q. Foul odour and bad taste of water is removed by treating with

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Q. Presence of __________ in water stream are deleterious to aquatic life.

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