Practice Test: Question Set - 09
1. Which of the following plants does not emit appreciable amount of SO2 in atmosphere?
- (A) Thermal power plant
- (B) Petroleum refinery
- (C) Nitric acid plant
- (D) Sulphuric acid plant
2. In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks.
- (A) 1 to 2
- (B) 4 to 5
- (C) 9 to 10
- (D) 15 to 20
3. 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
4. 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
5. 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) Peroxyacetyl nitrate
- (C) Carbon monoxide
- (D) Sulphur dioxide
6. 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 and diarrhea
- (D) All (a), (b) and (c)
7. Sulphur dioxide present in the industrial chimney exhaust gases causes
- (A) Respiratory & lung disease
- (B) Reduction in plant's productivity owing to acid rain
- (C) Corrosion of building materials
- (D) All (a), (b) and (c)
8. Phenolic water generated in coke ovens & by-product plant of a steel plant are disposed off by
- (A) Quenching of hot coke
- (B) Discharging in the river stream
- (C) Filtration and recycling for cooling coke oven gas
- (D) None of these
9. Corrosion in boilers can be prevented by
- (A) Deaeration of feed water
- (B) Enhancing pH of feed water by adding alkali
- (C) Feeding sodium sulphite or hydrazine phosphate to the boilers, which
combines with oxygen and prevents corrosion
- (D) All (a), (b) and (c)
10. During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.
- (A) Filtration
- (B) Digestion
- (C) Sedimentation
- (D) Both (b) and (c)
11. Fine grit present in sewage is removed in the __________ during sewage treatment.
- (A) Grit chamber
- (B) Detritus tank
- (C) Trickling filter
- (D) Skimming tank
12. Which of the following pollutants is absent in the emissions from a fertilizer plant?
- (A) SO2 & SO3
- (B) NO2
- (C) NH3
- (D) CO
13. Out of the following, TLV of __________ is maximum (about 500 ppm).
- (A) Carbon dioxide
- (B) Toluene
- (C) Carbon disulphide
- (D) Acetaldehyde
14. The biological decomposition of organic substances in wastes controlled conditions is called
- (A) Incineration
- (B) Biological oxidation
- (C) Composting
- (D) None of these
15. Threshold limit value (TLV) means maximum permissible/acceptable concentration. TLV of phosgene in air is about __________ ppm (parts per million).
- (A) 0.002
- (B) 0.2
- (C) 1.2
- (D) 4.8
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