Scale formation in boiler is controlled by Preheating of feed water Keeping the pH value of feed water just below 7 Eliminating H₂S in feed water Reduction in hardness, silica & alumina in feed water TRUE ANSWER : ? YOUR ANSWER : ?
Inhalation of silica dust by human being causes Asphyxiation Both B & C Shortness of breath Tuberculosis TRUE ANSWER : ? YOUR ANSWER : ?
TLV of ozone (O₃) and phosgene (COCl₂) in air is __________ ppm. 0.1 25 1000 100 TRUE ANSWER : ? YOUR ANSWER : ?
Main pollutants released from iron & steel industry is CO, CO₂ & SO₂ CO₂, H₂S & NO₂ H₂S, NO & SO₃ SO₃, NO₂ & CO₂ TRUE ANSWER : ? YOUR ANSWER : ?
High noise levels produced during operation of fans and compressors can be reduced by using Lagging of noisy duct None of these Accoustical absorbent Mufflers (silencers) TRUE ANSWER : ? YOUR ANSWER : ?
Removal of __________ is accomplished by aeration of water. Dissolved gases Dissolved solids Suspended solids None of these TRUE ANSWER : ? YOUR ANSWER : ?
Lagoons used for purification of polluted water All of these Use micro-organisms/bacteria in presence of dissolved oxygen Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre TRUE ANSWER : ? YOUR ANSWER : ?
'Pneumoconiosis' is a disease caused by the inhalation of __________ dust. Lime Uranium ore Coal Iron ore TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following processes is involved in the biochemical treatment of sewage effluents? Oxidation Fermentation Reduction Dehydration TRUE ANSWER : ? YOUR ANSWER : ?
Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes Anaemia Blood poisoning All of these Nervous system disorder TRUE ANSWER : ? YOUR ANSWER : ?