Nitrogen oxides (NOx) is not produced in the ______________ industry?
(A) Nitric acid making
(B) Nitrogenous fertiliser
(C) Detergent
(D) Any of these
TLV of ammonia, nitrogen dioxide and phenol vapor in air is ______________ ppm ?
(A) 5
(B) 100
(C) 1000
(D) 2000
In water treatment, alum [Al2(SO4)3] is used for the process of __________________?
(A) Filtration
(B) Coagulation
(C) Sedimentation
(D) Disinfection
Which of the following is not a secondary air pollutant ?
(A) Ozone
(B) Photochemical smog
(C) Sulphur dioxide
(D) All
Which of the following dust collection equipments is the least efficient (for sub-micronic particles) ?
(A) Dust catcher (gravity type)
(B) Cyclone separator
(C) Bag filter
(D) Hollow wet scrubber
Shouting by a man at his full voice corresponds to a voice level of about _____________ decibels?
(A) 25
(B) 50
(C) 80
(D) 120
Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds ______________ percent (by volume)?
(A) 1
(B) 3
(C) 7
(D) 20
Which of the following is a green house gas other than CO2 ?
(A) Methane
(B) Nitrous oxide
(C) Chlorofluoro carbons (CFC)
(D) All
Foaming and priming in boiler operation can be reduced by reduction in ______________ in feed water?
(A) Turbidity
(B) Color (Hazen)
(C) Total solids
(D) All
The amount of chemical coagulant added for treatment of polluted water ______________ with increase in temperature of the polluted water to be treated?
(A) Decreases
(B) Increases
(C) Remain constant
(D) May increase or decrease; depends on the chemical characteristics of polluted water