chemical engineering chemical environmental engineering chemical engineering Mcqs
51. There are thirteen metals which are treated as pollutants. Which of the following metals is not a pollutant ?
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A. Mercury

B. Aluminium

C. Lead

D. Arsenic

52. Arsenic pollutant is not generated in _______________ industries?
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A. Tanneries

B. Glass & ceramic

C. Any of these

D. Beverages
53. Pollution by particulate matter emission in the atmosphere does not take place during metal____________________?
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A. Machining

B. Grinding

C. Polishing

D. Cutting

54. Threshold limit value (TLV) of CO in air is _____________ ppm?
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A. 50

B. 5000

C. 2000

D. 5

55. Main pollutants released from iron & steel industry is__________________?
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A. SO3, NO2 & CO2

B. CO2, H2S & NO2

C. CO, CO2 & SO2

D. H2S, NO & SO3

56. . Operating principle of cyclone separator is based on the action of _______________ dust particles?
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A. Diffusion of

B. Electrostatic force on

C. Gravitational force on

D. Centrifugal force on
57. Main pollutants released from petroleum refineries is__________________?
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A. CO2, H2S & NO2

B. CO, SO2 & H2S

C. SO3, NO2 & CO2

D. CO2, NO & SO3

58. Siderosis is a disease caused by the inhalation of ______________ dust?
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A. Iron

B. Silica

C. Coal

D. None of these

59. Carcinogenic air pollutants cause__________________?
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A. Cancer

B. Bone decay

C. Asphyxiation (suffocation)

D. Anemia

60. Pick out the correct statement ?
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A. hromate in cone, sulphuric acid solution at boiling temperature for specified time

B. Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present

C. tes. Typically COD of potable water may be 1-2 mg/litre

D. COD is determined by oxidising the organic matter present in water with potassium

E. COD is related to BOD of a given waste in water but the relationship varies for different

F. water

61. In troposphere (the weather domain), the temperature t at height h above the spa level in metres is given by (where, temperature at sea level is 15C and t is in C ?
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A. t = 0.0035h -15

B. t = 15 + 0.0065h

C. t = 15 0.0035h

D. t = 15 0.0065h
62. Hazardous/polluting chemical industries should have an exclusion zone with a green belt and general public access prohibited around it, covering a radius of _____________ metres?
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A. 4000

B. 400

C. 1000

D. 100

63. Smog is ______________________?
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A. Nothing but black smoke

B. A solid particle e.g. fly-ash

C. A combination of smoke and fog

D. A liquid particle resulting from vapor condensation

64. Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent___________________?
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A. Corrosion

B. Water-borne disease

C. Scale formation

D. Dental cavities
65. Which of the following processes is involved in the biochemical treatment of sewage effluents ?
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A. Dehydration

B. Oxidation

C. Fermentation

D. Reduction

66. Worlds worst radioactive pollution was caused by nuclear reactor disaster which occured in ___________________?
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A. Chernobyl (undivided U.S.S.R.)

B. Pennsylvania (U.S.A.)

C. Moscow (U.S.S.R.)

D. Arizona (U.S.A.)

67. Water filtration rate in a slow sand filter ranges from ____________ litres/m2/hr?
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A. 100 to 200

B. 1500 to 2500

C. 10 to 20

D. 4000 to 5000

68. Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds ______________ percent (by volume)?
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A. 1

B. 3

C. 20

D. 7

69. Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about ______________ decibels?
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A. 95

B. 140

C. 75

D. 120

70. 5-200 ?m size particles are called__________________?
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A. Dust

B. Smoke

C. Colloids or aerosols

D. Powder

71. 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____________________?
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A. Automobiles exhaust

B. Burning of domestic fuel

C. Photochemical reaction in polluted atmosphere

D. Industrial chimney exhaust

72. Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate ?
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A. CFC (chloro fluoro carbons)

B. SO2

C. NOx

D. CO
73. 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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A. Troposphere

B. None of these

C. Ionosphere

D. Stratosphere

74. Pick out the wrong statement. A. Caustic embrittlement of boilers metallic parts is caused by high concentration of caustic soda in boiler feed water___________________?
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A. ica in feed water goes on decreasing

B. Dissolved oxygen content in high pressure boiler feed water should be nil

C. Cooling and freezing of water kills the bacteria present in it

D. With increasing boiler operating pressure of steam, the maximum allowable concentration of

75. 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_________________?
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A. With greater number of blades

B. Of increased diameter

C. Both A. & B.

D. Neither A. nor B.

76. Brown spots in fabrics will be caused by washing with water containing large amount of___________________?
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A. Iodine

B. Zinc

C. Iron

D. Bromine

77. Presence of iron and manganese in water causes___________________?
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A. Discoloration of bathroom fixtures

B. None of these

C. Temporary hardness

D. Reduction in its dissolved oxygen content

78. The Killer gas which caused Bhopal gas tragedy in 1984 was________________?
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A. Sulphur dioxide

B. Phosgene

C. Methyl isocyanate (MIC)

D. Carbon monoxide

79. Noise level heard at a distance of about 100 metres from a jet engine with after burner is about _____________ decibels?
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A. 140

B. 170

C. 200

D. 120

80. Which of the following is not a practical method of low level radioactive waste disposal ?
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A. Discharging to atmosphere through tall stacks after dilution

B. Dilution with inert material

C. Filling in steel crates and shooting it off out of earths gravity

D. Disposing off in rivers & oceans

81. Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may cause___________________?
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A. Explosion

B. Non biodegradable foam

C. Undesirable plant growth

D. Corrosion

82. Insufficient washing of sand grains in a rapid sand filter causes__________________?
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A. Air binding

B. Mud balls

C. Shrinkage of filtering media

D. Expansion of filtering media

83. As per the world health organisation (WHO) specification, the maximum permissible concentration (i.e., TLV) of particulate matter in air is _____________ ?g/m3.(?g-microgram)?
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A. 10

B. 90

C. 750

D. 800

84. The upper layer of atmosphere is called the ____________________?
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A. Troposphere

B. Stratosphere

C. None of these

D. Ionosphere

85. Hydrogen ion concentration in distilled water is___________________?
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A. 7 107

B. 10-7

C. 7 10-7

D. 107

86. Green house effect is accentuated by________________?
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A. Increased transportation activity

B. Rapid industrialisation

C. All A., B. and C.

D. Deforestation

87. Lagooning process is mainly a means of the__________________?
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A. Sludge disposal

B. Biological treatment of wastes

C. None of these

D. Reduction of excessive flow in sewers

88. Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is _______________ micro gram (? g)/litre?
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A. 42

B. 1050

C. 22

D. 332

89. Removal of ______________ is accomplished by aeration of water?
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A. Dissolved solids

B. None of these

C. Dissolved gases

D. Suspended solids

90. During sewage treatment, the sewage is subjected to ______________ treatment in Imhoff tank?
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A. Filtration

B. Digestion

C. Sedimentation

D. Both B. and C.
91. The earths atmosphere is an envelope of gases present upto a height of about ______________ kms?
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A. 2000

B. 1000

C. 10

D. 200
92. Presence of nitrates in water in excess of 50 ppm causes________________?
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A. Tooth decay

B. Methemoglobinemia

C. Gastroenteritis

D. Asphyxiation

93. Which of the following is not a source of ozone emission in the atmosphere?
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A. Dermatological photo-therapy equipments

B. Refrigerators

C. High voltage electrical equipments

D. Xerox machines

94. Iron & manganese present as pollutant in water cannot be removed by__________________?
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A. Chlorination

B. Oxidation followed by settling & filtration

C. Ion exchange process

D. Lime soda process or manganese zeolite process

95. Lagoons used for purification of polluted water_______________?
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A. id < 1 mg/litre and BOD = 3.8 mg/litre

B. All A., B. & C.

C. dation ponds

D. Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended

E. Use micro-organisms/bacteria in presence of dissolved oxygen

F. Are large shallow artificial lakes also known as clarification lakes, maturation ponds or

96. Noise level audible to audience sitting in the 5th row from the stage during a large orchestra show corresponds to about _______________ decibels?
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A. 105

B. 160

C. 185

D. 135
97. Polyvinyl chloride containers are not suitable for storing_________________?
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A. Foodstuffs

B. Metallic powder

C. None of these

D. Woolen clothes

98. High noise levels produced during operation of fans and compressors can be reduced by using__________________?
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A. Mufflers (silencers)

B. Acoustic absorbent

C. Lagging of noisy duct

D. None of these

99. Most efficient and suitable dust removal equipment for removal of fly-ash from flue gas in a thermal power plant is the__________________?
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A. Gravity settling chamber

B. Bag filter

C. Cyclone separator

D. Electrostatic precipitator
100. Removal of ______________ results from the disinfection of water?
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A. Hardness

B. Turbidity

C. Bacteria

D. Odour