Practice Test: Question Set - 19
1. Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million).
- (A) 50
- (B) 1000
- (C) 2000
- (D) 5000
2. Higher concentration of CO2 in atmosphere
- (A) Allows visible solar radiation (ultraviolet) of short wave-length to
pass through
- (B) Reflects and absorbs the longer wavelength (infra-red) radiations
- (C) Prevents solar heat being radiated out completely, resulting in
'heat trap' i.e., global warming
- (D) All (a), (b) and (c)
3. Dissolved oxygen content in river water is around __________ ppm.
- (A) 5
- (B) 100
- (C) 250
- (D) 500
4. Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes
- (A) Blood poisoning
- (B) Anaemia
- (C) Nervous system disorder
- (D) All (a), (b) & (c)
5. Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as
- (A) Photochemical smog
- (B) Peroxyacetyl nitrate (PAN) or methyl nitrite
- (C) Benzopyrene
- (D) Polyacrylonitrile
6. Maximum permissible turbidity in potable water is __________ ppm.
- (A) 1
- (B) 10
- (C) 250
- (D) 1000
7. Presence of excess fluorine in water causes
- (A) Dental cavity
- (B) Tooth decay
- (C) Fluorosis
- (D) Respiratory disease
8. TLV of aldrin in public water supply system is about __________ μg/liter.
- (A) 0.5
- (B) 17
- (C) 357
- (D) 1097
9. H2S present in gaseous stream can be removed by adsorption on
- (A) Silica gel
- (B) Active carbon
- (C) Bog iron
- (D) Limestone powder
10. Aerobic biological oxidation ponds used for the purification of polluted water
- (A) Destroys/removes pathogen from the sewage
- (B) Is not very effective for non-biodegradable substances (e.g. ABS)
containing effluents
- (C) Destroys/removes pathogen much more effectively if the sewage is
chlorinated
- (D) All (a), (b) & (c)
11. Radioactive substances present in the polluted water stream can be removed by
- (A) Biological oxygen treatment
- (B) Coagulation and filtration
- (C) Adsorption in ion exchange materials
- (D) None of these
12. Iron & manganese present in the polluted water is removed by
- (A) Simple filtration
- (B) Oxidation followed by settling & filtration
- (C) Chemical coagulation
- (D) Chlorination only
13. TLV of ozone (O3) and phosgene (COCl2) in air is __________ ppm.
- (A) 0.1
- (B) 25
- (C) 100
- (D) 1000
14. BOD of raw municipal sewage may be in the range of about __________ mg/liter.
- (A) 1-2
- (B) 5-10
- (C) 150-300
- (D) 2000-3000
15. Presence of bacteria in potable (drinking) water causes
- (A) Turbidity
- (B) Disease
- (C) Bad odour
- (D) Bad taste & color
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