The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the_________________?
(A) Ionosphere
(B) Troposphere
(C) Stratosphere
(D) None of these
TLV of NO2 & NO exposure for the human being is 5 & 25 ppm respectively. Prolonged exposure of human being to NO2 causes_________________?
(A) Skin disorder
(B) Bronchitis
(C) Bone disease
(D) Cancer
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
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
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
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
Exposure to SO2 containing chimney gases results in the__________________?
(A) Reduction in strength of leather & cloth
(B) Acceleration of corrosion rates of metals
(C) Increased drying & hardening time of paints
(D) All
Higher concentration of nitrogen dioxide in atmospheric air causes___________________?
(A) Cancer
(B) Bronchitis
(C) Asphyxiation
(D) Corrosion
Which is the most widely used coagulant for the treatment of turbid water ?
(A) Alum (aluminium sulphate)
(B) Lime
(C) Ferric chloride
(D) Sodium aluminate
A man exposed to excessive noise level in the working environment may suffer from____________________?
(A) Hearing loss
(B) Rupture of ear drum
(C) Nervousness & fatigue
(D) All