131.Operating principle of cyclone separator is based on the action of _________ dust particles.
Diffusion of
Centrifugal force on
Gravitational force on
Electrostatic force on
Correct answer: (B) Centrifugal force on
132.Out of the following, TLV of _________ is maximum (about 500 ppm).
Carbon dioxide
Toluene
Carbon disulphide
Acetaldehyde
Correct answer: (A) Carbon dioxide
133.Ozone is
A primary pollutant
A secondary pollutant
Impervious to ultra-violet rays
Both (B) and (C)
Correct answer: (D) Both (B) and (C)
134.Ozone level is generally found to be depleted in India in the month of
February
July
April
December
Correct answer: (D) December
135.Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called
Grit
Dust
Powder
Smoke
Correct answer: (A) Grit
136.Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called
Fumes
Mists
Smoke
Aerosols
Correct answer: (D) Aerosols
137.Permissible safe limit (TLV) of _________ toxic gas is 100-1000 parts per million (ppm).
Highly
Moderately
Extremely
Very extremely
Correct answer: (B) Moderately
138.Peroxyacetyl nitrate (PAN), a pollutant is found in the
Automobile exhaust
Flue gas of coal based power plant
Exhaust of nitric acid plant
Exhaust of sulphuric acid plant
Correct answer: (A) Automobile exhaust
139.Persons working in cement plants and limestone quarries are more prone to disease like
Cancer
Asthma
Silicosis
Fluorosis (bone disease)
Correct answer: (C) Silicosis
140.Phenolic water generated in coke ovens&by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by
Chlorination
Treating in biological oxygen pond
Chemical coagulation
None of these
Correct answer: (B) Treating in biological oxygen pond