Deaeration of feed water
Enhancing pH of feed water by adding alkali
Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion
All of the above
✅ The correct answer is option D.
Enviornmental Engineering MCQs
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
Global warming
Green house
Atmospheric effect
Ionosphere
✅ The correct answer is option B.
The principal gas evolved from sludge digestion tank is
CO
CO₂
CH₄
N₂
✅ The correct answer is option C.
Which is a secondary air pollutant?
Photochemical smog
Sulphur dioxide
Nitrogen dioxide
Dust particles
✅ The correct answer is option A.
Global warming may result in
Flood
Cyclone
Decrease in food productivity
All of the above
✅ The correct answer is option D.
‘Pneumoconiosis’ is a disease caused by the inhalation of __________ dust.
Coal
Uranium ore
Iron ore
Lime
✅ The correct answer is option A.
Beyond what concentration of H₂S in air, acute danger to human life exists?
50 ppm
100 ppm
300 ppm
700 ppm
✅ The correct answer is option D.
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.
75
95
120
140
✅ The correct answer is option B.
The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about __________ decibels.
60
90
105
120
✅ The correct answer is option B.
Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?
I-131
Sr-90
Au-198
Ra-226
✅ The correct answer is option D.