chemical engineering MCQs – Page 395

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
7881. Higher concentration of CO2 in atmosphere_____________________?
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A. Reflects and absorbs the longer wavelength (infra-red) radiations

B. Prevents solar heat being radiated out completely, resulting in heat trap i.e., global warming

C. All A., B. and C.

D. Allows visible solar radiation (ultraviolet) of short wave-length to pass through

7882. Maximum permissible limit of industrial noise as recommended by World Health Organisation (WHO) is _____________ decibels?
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A. 105

B. 75

C. 35

D. 95

7883. Particulate air pollutants are finely divided solids and liquids. Which of the following is not a particulate? ?
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A. Dust & mists

B. None of these

C. Photochemical smog & soot

D. Smoke & fumes

7884. What are the methods of treatment & disposal of radioactive wastes ?
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A. Evaporation & chemical precipitation

B. All A., B. & C.

C. Fixing into a solid mass with cement and sinking deep in the sea

D. Biological methods & adsorption in ion exchange materials

7885. The pH value of potable water should be between____________________?
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A. 6.5 to 8

B. 1 to 1.5

C. 4 to 5

D. 13 to 14

7886. Which of the following pollutants is absent in the emissions from a fertiliser plant ?
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A. NO2

B. NH3

C. SO2 & SO3

D. CO
7887. Presence of iron and manganese in water causes___________________?
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A. Temporary hardness

B. None of these

C. Reduction in its dissolved oxygen content

D. Discoloration of bathroom fixtures
7888. In Joule-Thomson porous plug experiment, the__________________?
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A. Enthalpy does not remain constant

B. Temperature remains constant

C. None of these

D. Entire apparatus is exposed to surroundings

7889. Permissible safe limit (TLV) of _____________ toxic gas is 100-1000 parts per million (ppm)?
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A. Highly

B. Moderately

C. Extremely

D. Very extremely

7890. Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in____________________?
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A. Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter

B. the nitrite and eventually to the nitrate

C. All A., B. and C.

D. Oxidation of carbonaceous matter to CO2

E. Coagulation and flocculation of colloids

7891. Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by________________?
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A. Natural aeration of water stream

B. Photosynthetic action of algae

C. Both A. & B.

D. Neither A. nor B.

7892. TLV of aldrin in public water supply system is about ____________ ?g/litre?
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A. 357

B. 0.5

C. 17

D. 1097

7893. Which of the following sources is responsible for maximum air pollution ?
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A. Photochemical oxidation of organic matter

B. Industrial chimney exhaust

C. Forest fire

D. Automobiles exhaust
7894. Pick out the wrong statement ?
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A. characterised by a steady decrease in temperature is called stratosphere</strong>

B. Troposphere is a turbulent dusty zone containing much of water vapor and clouds

C. The earths atmosphere is an envelope of gases extending upto a height of about 200 kms

D. Stratosphere is rich in ozone and is located just above the troposphere

E. The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere
7895. Which is the most widely used coagulant for the treatment of turbid water ?
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A. Sodium aluminate

B. Alum (aluminium sulphate)

C. Ferric chloride

D. Lime

7896. Presence of nitrates in water in excess of 50 ppm causes________________?
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A. Tooth decay

B. Gastroenteritis

C. Asphyxiation

D. Methemoglobinemia
7897. Tri-sodium phosphate is used in boiler water treatment to reduce____________________?
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A. Turbidity

B. Caustic embrittlement

C. Dissolved oxygen

D. Suspended silica

7898. Main pollutant present in automobile exhaust is_________________?
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A. Hydrocarbons

B. CO2

C. CO

D. NO

7899. Inhalation of silica dust by human being causes ___________________?
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A. Asphyxiation

B. Shortness of breath

C. Tuberculosis

D. Both B. & C.
7900. Fresh domestic sewage is _______________ in color?
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A. Black

B. Red

C. Grey

D. Dark brown