MCQOPTIONS
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MCQOPTIONS
This section includes 444 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Presence of __________ bacteria in water causes disease like typhoid. |
| A. | Aerobic |
| B. | Pathogenic |
| C. | Anaerobic |
| D. | Non-pathogenic |
| Answer» C. Anaerobic | |
| 52. |
Lagoons used for purification of polluted water |
| A. | Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds |
| B. | Use micro-organisms/bacteria in presence of dissolved oxygen |
| C. | Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre |
| D. | All of the above |
| Answer» E. | |
| 53. |
Aerosols present in atmospheric air may be |
| A. | Positively charged |
| B. | Negatively charged |
| C. | Neutral |
| D. | Combination of all A, B & C |
| Answer» E. | |
| 54. |
Reinglemann chart is used for the measurement of the |
| A. | Combustibles present in automobile exhaust |
| B. | Smoke density from a chimey |
| C. | Exhaust gas density |
| D. | Flue gas temperature |
| Answer» C. Exhaust gas density | |
| 55. |
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the |
| A. | Bacterial stability factor |
| B. | Relative stability |
| C. | Biological oxygen demand (BOD) |
| D. | Oxygen ion concentration |
| Answer» C. Biological oxygen demand (BOD) | |
| 56. |
Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters? |
| A. | I-131 |
| B. | Sr-90 |
| C. | Au-198 |
| D. | Ra-226 |
| Answer» E. | |
| 57. |
Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. |
| A. | Coal ash |
| B. | Potassium cyanide |
| C. | Ortho-xylene |
| D. | None of these |
| Answer» C. Ortho-xylene | |
| 58. |
Which of the following is not a weightless pollutant? |
| A. | SPM |
| B. | Thermal pollution |
| C. | Radioactive rays |
| D. | Noise pollution |
| Answer» B. Thermal pollution | |
| 59. |
In the context of the chemical process industries, the term BOD is normally associated with the |
| A. | Characterisation of solid wastes |
| B. | Organic concentration in gaseous effluents |
| C. | Characterisation of liquid effluents |
| D. | Characterisation of boiler feed water |
| Answer» D. Characterisation of boiler feed water | |
| 60. |
Removal of __________ results from the disinfection of water. |
| A. | Turbidity |
| B. | Odour |
| C. | Hardness |
| D. | Bacteria |
| Answer» E. | |
| 61. |
The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is |
| A. | Pipe vibrations |
| B. | Cavitation |
| C. | Boundary layer separation |
| D. | Fluctuation in liquid flow |
| Answer» C. Boundary layer separation | |
| 62. |
Growth of __________ is promoted by the presence of manganese in water. |
| A. | Files |
| B. | Algae |
| C. | Micro-organisms |
| D. | Mosquitoes |
| Answer» D. Mosquitoes | |
| 63. |
Ionisation potential employed in the industrial electrostatic precipitator is of the order of |
| A. | 30 to 70 kV DC |
| B. | 30 to 70 kV AC |
| C. | 230 V AC |
| D. | 230 V DC |
| Answer» B. 30 to 70 kV AC | |
| 64. |
Which of the following processes is involved in the biochemical treatment of sewage effluents? |
| A. | Oxidation |
| B. | Reduction |
| C. | Dehydration |
| D. | Fermentation |
| Answer» B. Reduction | |
| 65. |
Thermal pollution due to excessive heat & temperature in the working place causes |
| A. | Reduction in working efficiency of manpower |
| B. | Fatigue |
| C. | High breathing rate |
| D. | All of the above |
| Answer» E. | |
| 66. |
Salt content in sea water is about __________ percent. |
| A. | 0.5 |
| B. | 1 |
| C. | 3.5 |
| D. | 10 |
| Answer» D. 10 | |
| 67. |
Noise level heard at a distance of about 100 metres from a jet engine with after burner is about __________ decibels. |
| A. | 120 |
| B. | 140 |
| C. | 170 |
| D. | 200 |
| Answer» D. 200 | |
| 68. |
Turbidity of water is an indication of the presence of |
| A. | Suspended inorganic matter |
| B. | Dissolved solids |
| C. | Floating solids |
| D. | Dissolved gases |
| Answer» B. Dissolved solids | |
| 69. |
Aerobic biological oxidation ponds used for the purification of polluted water |
| A. | Destroys/removes pathogen from the sewage |
| B. | Is not very effective for nonbiodegradable substances (e.g. ABS) containing effluents |
| C. | Destroys/removes pathogen much more effectively if the sewage is chlorinated |
| D. | All of the above |
| Answer» E. | |
| 70. |
When the concentration of SO₂ in air is greater than __________ ppm, it gives a pungent smell. |
| A. | 0.01 |
| B. | 0.1 |
| C. | 1 |
| D. | 4 |
| Answer» E. | |
| 71. |
Which of the following fine dust removal equipments is the most efficient? |
| A. | Bag filter |
| B. | Scrubber |
| C. | Electrostatic precipitator |
| D. | Cyclone separator |
| Answer» D. Cyclone separator | |
| 72. |
High noise level in a chemical plant can be controlled by the |
| A. | Suppression of noise at the source itself |
| B. | Path control of noise |
| C. | Protection of operating personnel |
| D. | All of the above |
| Answer» E. | |
| 73. |
Ozone is |
| A. | A primary pollutant |
| B. | A secondary pollutant |
| C. | Impervious to ultra-violet rays |
| D. | Both B & C |
| Answer» E. | |
| 74. |
Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for |
| A. | Conversion of CO into CO₂ in the second compartment |
| B. | Conversion of NOx into N₂ and NH₃ in the first compartment |
| C. | Oxidation of unburnt hydrocarbon fuel in the second compartment |
| D. | All of the above |
| Answer» E. | |
| 75. |
Algae growth in water is controlled by |
| A. | Deoxidation |
| B. | Chlorination |
| C. | Bleaching |
| D. | Aeration |
| Answer» C. Bleaching | |
| 76. |
Dust collection efficiency of a cyclone separator depends upon its |
| A. | Diameter |
| B. | Inlet gas velocity |
| C. | Overall height |
| D. | All of the above |
| Answer» E. | |
| 77. |
Which of the following causes death by asphyxiation, if its presence in atmospheric air exceeds maximum allowable concentration (i.e. > 50 ppm)? |
| A. | Benzopyrene |
| B. | Peroxyacyl nitrate |
| C. | Carbon monoxide |
| D. | Sulphur dioxide |
| Answer» D. Sulphur dioxide | |
| 78. |
A 'body' which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called the |
| A. | Global warming |
| B. | Green house |
| C. | Atmospheric effect |
| D. | Ionosphere |
| Answer» C. Atmospheric effect | |
| 79. |
The pH value of potable water should be between |
| A. | 1 to 1.5 |
| B. | 6.5 to 8 |
| C. | 13 to 14 |
| D. | 4 to 5 |
| Answer» C. 13 to 14 | |
| 80. |
Presence of bacteria in potable (drinking) water causes |
| A. | Turbidity |
| B. | Disease |
| C. | Bad odour |
| D. | Bad taste & colour |
| Answer» C. Bad odour | |
| 81. |
Arsenic pollutant is not generated in____industries. |
| A. | Tanneries |
| B. | Glass & ceramic |
| C. | Beverages |
| D. | Any of these |
| Answer» D. Any of these | |
| 82. |
Which of the following is not a secondary air pollutant? |
| A. | Ozone |
| B. | Photochemical smog |
| C. | Sulphur dioxide |
| D. | All of the above |
| Answer» D. All of the above | |
| 83. |
The main industrial source of emission of hydrogen sulphide air pollutant is |
| A. | Petroleum refineries |
| B. | Coal based thermal power plants |
| C. | Pulp and paper plant |
| D. | Metallurgical roasting & smelting plant |
| Answer» C. Pulp and paper plant | |
| 84. |
The concentration of water vapour in troposphere, which depends upon the altitude & temperature varies in the range of zero to __________ percent. |
| A. | 1 |
| B. | 4 |
| C. | 8 |
| D. | 12 |
| Answer» C. 8 | |
| 85. |
Lagooning process is mainly a means of the |
| A. | Sludge disposal |
| B. | Reduction of excessive flow in sewers |
| C. | Biological treatment of wastes |
| D. | None of these |
| Answer» B. Reduction of excessive flow in sewers | |
| 86. |
'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 |
| Answer» C. Photochemical reaction in polluted atmosphere | |
| 87. |
Which of the following is an adsorbant for removal of nitrogen oxides from gas/air? |
| A. | Active carbon |
| B. | Silica gel |
| C. | Bog iron (iron oxide) |
| D. | Pulverised limestone |
| Answer» C. Bog iron (iron oxide) | |
| 88. |
Direct reaction of unsaturated hydrocarbons with either NO or NO₂ produces an eye irritating pollutant compound known as |
| A. | Photochemical smog |
| B. | Peroxy acetyl nitrate (PAN) or methyl nitrile |
| C. | Benzopyrene |
| D. | Poly acrylonitrile |
| Answer» C. Benzopyrene | |
| 89. |
A masonry structure built below ground level, where biochemical reaction takes place due to anaerobic bacteria is called |
| A. | Cesspool |
| B. | Lagoon |
| C. | Skimming mill |
| D. | Septic tank |
| Answer» E. | |
| 90. |
Hydrogen ion concentration in distilled water is |
| A. | 10⁻⁷ |
| B. | 7 x 10⁻⁷ |
| C. | 10⁷ |
| D. | 7 x 10⁷ |
| Answer» B. 7 x 10⁻⁷ | |
| 91. |
In water chemical treatment plant, use of chloramines ensures |
| A. | Disinfection |
| B. | Taste & odour control |
| C. | Weed control in reservoirs |
| D. | Removal of permanent hardness |
| Answer» B. Taste & odour control | |
| 92. |
__________ plant emits large amount of SO₂ as an air pollutant. |
| A. | Nitric acid |
| B. | Sulphuric acid |
| C. | Chloralkali |
| D. | Iron & steel |
| Answer» C. Chloralkali | |
| 93. |
A man exposed to excessive noise level in the working environment may suffer from |
| A. | Hearing loss |
| B. | Rupture of ear drum |
| C. | Nervousness & fatigue |
| D. | All of the above |
| Answer» E. | |
| 94. |
During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum? |
| A. | Idle running |
| B. | Acceleration |
| C. | Cruising |
| D. | Deaccelaration |
| Answer» B. Acceleration | |
| 95. |
Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes |
| A. | Fire hazards |
| B. | Explosion hazards |
| C. | Persistent foam |
| D. | Depletion of dissolved oxygen |
| Answer» D. Depletion of dissolved oxygen | |
| 96. |
Removal of __________ is accomplished by aeration of water. |
| A. | Dissolved gases |
| B. | Suspended solids |
| C. | Dissolved solids |
| D. | None of these |
| Answer» B. Suspended solids | |
| 97. |
80% less than 200 mesh size particles are called |
| A. | Smoke |
| B. | Powder |
| C. | Grit |
| D. | Aggregates |
| Answer» C. Grit | |
| 98. |
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. |
| A. | <1 |
| B. | 10-100 |
| C. | 100-200 |
| D. | 100-1000 |
| Answer» B. 10-100 | |
| 99. |
Which of the following is a manmade source of air pollution? |
| A. | Automobile exhaust |
| B. | Forest fire |
| C. | Bacterial action in soil and swamp areas |
| D. | All of the above |
| Answer» B. Forest fire | |
| 100. |
Insufficient washing of sand grains in a rapid sand filter causes |
| A. | Air binding |
| B. | Shrinkage of filtering media |
| C. | Mud balls |
| D. | Expansion of filtering media |
| Answer» D. Expansion of filtering media | |