When the concentration of SO2 in air is greater than ______________ ppm, it gives a pungent smell?
(A) 0.01
(B) 0.1
(C) 1
(D) 4
Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
(A) Sedimentation
(B) Skimming off
(C) Chlorination
(D) Biological oxidation
Iron & manganese present as pollutant in water cannot be removed by__________________?
(A) Ion exchange process
(B) Oxidation followed by settling & filtration
(C) Lime soda process or manganese zeolite process
(D) Chlorination
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
Pick out the wrong statement pertaining to ‘green house’ for the plants ?
(A) ‘Green house’ (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants inside it
(B) The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house
(C) ‘Green house effect’ in earth’s atmosphere is due to increasing CO2 level in atmosphere, where CO2 acts like the glass of ‘green house’ thereby warming up the earth’s surface
(D) ‘Green house’ is colder than the outside atmosphere
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
Dust collection efficiency of a cyclone separator depends upon its______________?
(A) Diameter
(B) Inlet gas velocity
(C) Overall height
(D) All
The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is_________________?
(A) Pipe vibrations
(B) Cavitation
(C) Boundary layer separation
(D) Fluctuation in liquid flow
Main pollutants released from iron & steel industry is__________________?
(A) CO, CO2 & SO2
(B) H2S, NO & SO3
(C) CO2, H2S & NO2
(D) SO3, NO2 & CO2