Q.1
Higher concentration of CO₂ in atmosphere
Q.2
Foul odour and bad taste of water is removed by treating with
Q.3
Threshold limit value (TLV) means maximum permissible/acceptable concentration. TLV of phosgene in air is about __________ ppm (parts per million).
Q.4
Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is __________ micro gram (μ g)/litre.
Q.5
The earth's atmosphere is an envelope of gases present upto a height of about __________ kms.
Q.6
The maximum CO₂ is emitted into the atmosphere by
Q.7
Pick out the correct statement.
Q.8
The upper layer of atmosphere is called the
Q.9
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.
Q.10
CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing __________ molecules of ozones.
Q.11
Acute danger to human life (i.e. death) exists, if the concentration of CO₂ in atmospheric air exceeds __________ percent (by volume).
Q.12
In water treatment plant, zeolite process is used to remove the __________ of water.
Q.13
In large thermal power stations very fine particulates present in flue gas are removed by
Q.14
World environment day is observed every year on the 5th of
Q.15
Reingleman chart No. 2 corresponds to __________ percent black smoke.
Q.16
During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.
Q.17
Fine grit present in sewage is removed in the __________ during sewage treatment.
Q.18
On prolonged exposure to high concentration of carbon monoxide (> 5000 ppm), man dies because
Q.19
Which of the following dust collection equipments is the least efficient (for sub-micronic particles)?
Q.20
The function of skimming tank in sewage treatment is to remove __________ substances.
Q.21
Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes
Q.22
Septic tanks are used for the __________ of the deposited solids.
Q.23
Average human body contains about __________ percent water by weight.
Q.24
Peroxyacyl nitrate (PAN), a pollutant is found in the
Q.25
In water treatment, alum[Al2(SO₄)3] is used for the process of
Q.26
__________ is removed from water by lime-soda process.
Q.27
If carbon monoxide content in atmospheric air exceeds __________ ppm, death is bound to occur.
Q.28
Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in
Q.29
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.
Q.30
Noise level during normal conversation among men is about __________ decibles.
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