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.Management Sciences
Category: Chemical Environmental Engineering
Pick out the correct statement?
A. Noise from ball mills can be dealt with by fibre glass lined enclosures
B. Noise from vibrating chutes can be reduced by lining the metallic chute with rubber
C. Noise of conveyor belt system is reduced by using urethane coated cloth conveyor belts and
rubber/plastic covered metallic rollers
D. All A., B. & C.
Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by _____________________?
A. Chemical coagulation
B. Floatation & skimming
C. Centrifugation
D. Ultra filtration
‘Safe limit’ called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the____________________?
A. Industrial chimney exhaust
B. Automobiles exhaust
C. Photochemical reaction in polluted atmosphere
D. Burning of domestic fuel
Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called__________________?
A. Grit
B. Dust
C. Powder
D. Smoke
Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan_________________?
A. With greater number of blades
B. Of increased diameter
C. Both A. & B.
D. Neither A. nor B.
Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in___________________?
A. Food industry
B. Municipal sewage treatment
C. Petroleum refinery
D. Iron & steel plant
Deaeration of high pressure boiler feed water is done to reduce ___________________?
A. Foaming from boilers
B. Its dissolved oxygen content
C. Its silica content
D. Caustic embrittlement
Pick out the wrong statement?
A. Benzopyrene which causes cancer is present in traces in tobacco, charcoal & petrol driven
automobile exhaust
B. NO2 is capable of penetrating the troposphere and can absorb both ultraviolet & visible light
C. Hydrocarbon pollutants are produced by sweet gum, oak & natural rubber trees
D. H2S is not at all produced during combustion of sulphur bearing fuels as all the sulphur is
oxidised to SO2
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