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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.
351. |
_Algae growth in water is controlled by$? |
A. | Deoxidation |
B. | Chlorination |
C. | Bleaching |
D. | Aeration |
Answer» C. Bleaching | |
352. |
_Presence of __________ bacteria in water causes disease like typhoid.$? |
A. | Aerobic |
B. | Pathogenic |
C. | Anaerobic |
D. | Non-pathogenic |
Answer» C. Anaerobic | |
353. |
_Smog is not formed due to the presence of __________ in the atmosphere.$? |
A. | SO‚ÇÇ |
B. | NOx |
C. | CO‚ÇÇ |
D. | Any of these |
Answer» D. Any of these | |
354. |
_Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate?$? |
A. | CO |
B. | SO‚ÇÇ |
C. | NOx |
D. | CFC (chloro fluoro carbons) |
Answer» B. SO‚Äö√á√á | |
355. |
_The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant?$? |
A. | Chlorine |
B. | Alkalis |
C. | Benzene hexachloride |
D. | Alkyl benzene sulphonate (ABS) |
Answer» B. Alkalis | |
356. |
_The pH value of oxidised sewage is about$? |
A. | 1.8 |
B. | 6.2 |
C. | 7.3 |
D. | 13.4 |
Answer» D. 13.4 | |
357. |
_A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm.$? |
A. | 1000 to 2000 |
B. | 3000 to 6000 |
C. | 6000 to 9000 |
D. | 10000 to 100000 |
Answer» E. | |
358. |
_Tolerable limit of nitrogen oxides in air is __________ ppm.$? |
A. | 0.1 |
B. | 1 |
C. | 5 |
D. | 25 |
Answer» D. 25 | |
359. |
_Iron & manganese present as pollutant in water can not be removed by$? |
A. | Ion exchange process |
B. | Oxidation followed by settling & filtration |
C. | Lime soda process or manganese zeolite process |
D. | Chlorination |
Answer» E. | |
360. |
_Lung cancer & DNA breakage are the major ill effects of excessive ozone exposure to human beings. Ozone layer depletion in the atmosphere is mainly caused by the presence of$? |
A. | CO‚ÇÇ |
B. | SO‚ÇÇ |
C. | Hydrocarbons |
D. | CFC (chloro fluoro carbon) |
Answer» E. | |
361. |
_Which is a secondary air pollutant?$? |
A. | Photochemical smog |
B. | Sulphur dioxide |
C. | Nitrogen dioxide |
D. | Dust particles |
Answer» B. Sulphur dioxide | |
362. |
_Direct reaction of unsaturated hydrocarbons with either NO or NO‚ÇÇ produces an eye irritating pollutant compound known as$? |
A. | Photochemical smog |
B. | Peroxy acetyl nitrate (PAN) or methyl nitrile |
C. | Benzopyrene |
D. | Poly acrylonitrile |
Answer» C. Benzopyrene | |
363. |
_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.$? |
A. | <1 |
B. | 10-100 |
C. | 100-200 |
D. | 100-1000 |
Answer» B. 10-100 | |
364. |
_Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes$? |
A. | Fire hazards |
B. | Explosion hazards |
C. | Persistent foam |
D. | Depletion of dissolved oxygen |
Answer» D. Depletion of dissolved oxygen | |
365. |
_Which of the following is not a practical method of low level radioactive waste disposal?$? |
A. | Dilution with inert material |
B. | Discharging to atmosphere through tall stacks after dilution |
C. | Disposing off in rivers & oceans |
D. | Filling in steel crates and shooting it off out of earth |
Answer» E. | |
366. |
_In troposphere (the weather domain), the temperature 't' at height 'h' above the spa level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)$? |
A. | t = 15 - 0.0065h |
B. | t = 15 + 0.0065h |
C. | t = 0.0035h -15 |
D. | t = 15 - 0.0035h |
Answer» B. t = 15 + 0.0065h | |
367. |
_Fresh sewage is __________ in nature.$? |
A. | Acidic |
B. | Neutral |
C. | Alkaline |
D. | Highly acidic |
Answer» D. Highly acidic | |
368. |
_The main type of sludge gas evolved during sewage treatment in Imhoff tank is$? |
A. | CO‚ÇÇ |
B. | CH‚ÇÑ |
C. | CO |
D. | H‚ÇÇ |
Answer» C. CO | |
369. |
_Green house effect is accentuated by$? |
A. | Deforestation |
B. | Rapid industrialisation |
C. | Increased transportation activity |
D. | All of the above |
Answer» E. | |
370. |
_Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes$? |
A. | Paralysis of muscles & loss of appetite |
B. | Nervous depression |
C. | Gastritis & diarrhea |
D. | All of the above |
Answer» E. | |
371. |
_Which of the following is not a source of ozone emission in the atmosphere?$? |
A. | Refrigerators |
B. | Xerox machines |
C. | Dermatological photo-therapy equipments |
D. | High voltage electrical equipments |
Answer» B. Xerox machines | |
372. |
_Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in$? |
A. | Food industry |
B. | Municipal sewage treatment |
C. | Petroleum refinery |
D. | Iron & steel plant |
Answer» B. Municipal sewage treatment | |
373. |
_Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called$? |
A. | Grit |
B. | Dust |
C. | Powder |
D. | Smoke |
Answer» B. Dust | |
374. |
_A shallow pond in which the sewage is retained and biologically treated is called$? |
A. | Oxidation |
B. | Imhoff tank |
C. | Lagoon |
D. | Skimming tank |
Answer» B. Imhoff tank | |
375. |
_Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of$? |
A. | Ozone and iodine |
B. | Chlorine or its compounds |
C. | Ultraviolet light for irradiation of water |
D. | All of the above |
Answer» E. | |
376. |
_White smoke coming out of the chimney of a furnace indicates the use of$? |
A. | Low excess air |
B. | Very high excess air |
C. | Gaseous fuel in the furnace |
D. | Liquid fuel in the furnace |
Answer» C. Gaseous fuel in the furnace | |
377. |
_Presence of soluble organics in polluted water causes$? |
A. | Undesirable plants growth |
B. | Depletion of oxygen |
C. | Fire hazards |
D. | Explosion hazards |
Answer» C. Fire hazards | |
378. |
_Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.$? |
A. | 1 |
B. | 7 |
C. | 19 |
D. | 82 |
Answer» C. 19 | |
379. |
_TLV of NO‚ÇÇ & NO exposure for the human being is 5 & 25 ppm respectively. Prolonged exposure of human being to NO‚ÇÇ causes$? |
A. | Skin disorder |
B. | Bronchitis |
C. | Bone disease |
D. | Cancer |
Answer» C. Bone disease | |
380. |
_The upper layer of atmosphere is called the$? |
A. | Stratosphere |
B. | Troposphere |
C. | Ionosphere |
D. | None of these |
Answer» B. Troposphere | |
381. |
_Radioactive solid nuclear wastes are disposed off by$? |
A. | High temperature incineration |
B. | Pathological incineration |
C. | Pyrolysis |
D. | Underground burial in concrete containers |
Answer» E. | |
382. |
_Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes$? |
A. | Foaming |
B. | Odour nuisances |
C. | Undesirable plant growth |
D. | Turbidity |
Answer» D. Turbidity | |
383. |
_Exposure to chemicals having carcinogenic properties cause$? |
A. | Dermatitis (skin disorder) |
B. | Cancer |
C. | Asphyxiation |
D. | Asthma |
Answer» C. Asphyxiation | |
384. |
_Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO‚ÇÇ in air is __________ ppm.$? |
A. | 5 |
B. | 500 |
C. | 1000 |
D. | 2000 |
Answer» B. 500 | |
385. |
_In a sedimentation tank, the detention period for water ranges from __________ hours.$? |
A. | 2 to 4 |
B. | 8 to 12 |
C. | 16 to 20 |
D. | 24 to 32 |
Answer» B. 8 to 12 | |
386. |
_Septic tanks are used for the __________ of the deposited solids.$? |
A. | Separation |
B. | Anaerobic decomposition |
C. | Aerobic decomposition |
D. | None of these |
Answer» C. Aerobic decomposition | |
387. |
_Peroxyacyl nitrate (PAN), a pollutant is found in the$? |
A. | Automobile exhaust |
B. | Flue gas of coal based power plant |
C. | Exhaust of nitric acid plant |
D. | Exhaust of sulphuric acid plant |
Answer» B. Flue gas of coal based power plant | |
388. |
_Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.$? |
A. | Reduce SO‚ÇÇ content in |
B. | Catalytically convert SO‚ÇÇ to SO‚ÇÉ in |
C. | Increase the dew point of |
D. | None of these |
Answer» B. Catalytically convert SO‚Äö√á√á to SO‚Äö√á√â in | |
389. |
For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than __________ ppm.$? |
A. | 10000 |
B. | 5 |
C. | 500 |
D. | 1000 |
Answer» C. 500 | |
390. |
Which of the following air pollutants is not toxic to vegetation i.e., doesn't cause vegetation damage?$? |
A. | Smog & ozone |
B. | Hydrogen fluoride & nitrogen oxides |
C. | Sulphur dioxide & spray of weed killers |
D. | Carbon monoxide |
Answer» E. | |
391. |
Maximum permissible residual chlorine in treated water should be __________ mg/litre.$? |
A. | 0.001 to 0.01 |
B. | 02 to 0.3 |
C. | 2 to 3 |
D. | 5 to 10 |
Answer» C. 2 to 3 | |
392. |
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the$? |
A. | Bacterial stability factor |
B. | Relative stability |
C. | Biological oxygen demand (BOD) |
D. | Oxygen ion concentration |
Answer» C. Biological oxygen demand (BOD) | |
393. |
In the context of the chemical process industries, the term BOD is normally associated with the$? |
A. | Characterisation of solid wastes |
B. | Organic concentration in gaseous effluents |
C. | Characterisation of liquid effluents |
D. | Characterisation of boiler feed water |
Answer» D. Characterisation of boiler feed water | |
394. |
Most of the bacteria in sewage are$? |
A. | Parasitic |
B. | Saprophytic |
C. | Anerobic |
D. | None of these |
Answer» C. Anerobic | |
395. |
Shouting by a man at his full voice corresponds to a voice level of about __________ decibels.$? |
A. | 25 |
B. | 50 |
C. | 80 |
D. | 120 |
Answer» D. 120 | |
396. |
A standard test for determination of hardness in water is termed as __________ test.$? |
A. | EDTA |
B. | Electometric |
C. | Total count |
D. | Presumptive |
Answer» B. Electometric | |
397. |
Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm)$? |
A. | Acts as a green house gas thereby raising earth's temperature |
B. | Causes asphyxia |
C. | Causes increase in sea level |
D. | Inhances the green house effect |
Answer» C. Causes increase in sea level | |
398. |
Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels.$? |
A. | 85 |
B. | 105 |
C. | 125 |
D. | 145 |
Answer» C. 125 | |
399. |
Turbidity of water is an indication of the presence of$? |
A. | Suspended inorganic matter |
B. | Dissolved solids |
C. | Floating solids |
D. | Dissolved gases |
Answer» B. Dissolved solids | |
400. |
The principal gas evolved from sludge digestion tank is$? |
A. | CO |
B. | CO‚ÇÇ |
C. | CH‚ÇÑ |
D. | N‚ÇÇ |
Answer» D. N‚Äö√á√á | |