Q.1) Standard EDTA (ethylene diamine tetra acetic acid) solution is used to determine :
A) Hardness in water
B) Turbidity in water
C) Dissolved oxygen in water
D) Residual chlorine in water
Option (A)
Q.2) Turbidity is measured on –
A) Standard silica scale
B) Standard cobalt scale
C) Standard platinum scale
D) Platinum cobalt scale
Option (A)
Explanation :
Turbidity is the measure of amount of light scattering through water.
Q.3) The chemical most commonly used to increase the speed of sedimentation of sewage is –
A) Sulphuric acid
B) Copper sulphate
C) Lime
D) Sodium permanganate
Option (C)
Explanation :
Lime (calcium oxide or calcium hydroxide) can be used in sedimentation as a coagulant to help remove suspended particles from water.
When added to water, lime reacts with the impurities in the water and forms a sticky substance called a floc. This floc attracts and binds together suspended particles such as dirt, bacteria, and algae, causing them to settle to the bottom of the sedimentation tank or basin. Once the particles have settled, the clear water above the sediment can be removed and treated further for drinking or other uses.
Q.4) Chlorine demand of water is equal to –
A) Applied chlorine
B) Residual chlorine
C) Sum of applied and residual chlorine
D) Difference of applied and residual chlorine
Option (D)
Q.5) The process in which the chlorination is done beyond the break point is known as –
A) Prechlorination
B) Post chlorination
C) Super chlorination
D) Break Point chlorination
Option (C)
Q.6) Which of the following methods of analysis of water distribution system is most suitable for long and narrow pipe system?
A) Circle method
B) Equivalent pipe method
C) Hardy cross method
D) Electrical analysis method
Option (B)
Q.7) The minimum and maximum diameters of sewers shall preferably be –
A) 15 cm and 100 cm
B) 15 cm and 300 cm
C) 30 cm and 450 cm
D) 60 cm and 300 cm
Option (B)
Q.8) The pathogens can be killed by –
A) Nitrification
B) Chlorination
C) Oxidation
D) None of the above
Option (B)
Explanation :
Pathogen (such as : viruses, protozoa or parasite) is a disease causing micro-organisms that are capable of replicating and spreading within their host and damaging cells or tissues.
Q.9) Corrosion in concrete sewers is caused by –
A) Septic conditions
B) Dissolved oxygen
C) Chlorine
D) Nitrogen
Option (A)
Q.10) The detention period for oxidation ponds is usually kept as –
A) 4 – 8 Hrs
B) 24 Hrs
C) 10 – 15 days
D) 3 months
Option (C)
Q.11) Composting and lagooning are the methods of –
A) Sludge digestion
B) Sludge disposal
C) Sedimentation
D) Filtration
Option (B)
Q.12) Chlorine is used in the treatment of sewage to –
A) Help grease separation
B) Aid flocculation
C) Increase the biochemical oxygen demand
D) Cause bulking of activated sludge
Option (A)
Q.13) The intensification of green house effect is attributed to the increased level of :
A) Carbon dioxide
B) Carbon monoxide
C) Chlorofluorocarbons
D) Sulphur dioxides
Option (A)
Q.14) Electrostatic Precipitators are used as pollution control device for the separation of :
A)SO2
B)NOx
C)Hydrocarbon
D)Particulate matter
Option (D)
Q.15) Dechlorination of water is achieved by adding :
A) Sodium thiosulphate
B) Sodium sulphate
C) Sodium hexametaphosphate
D) Sodium bisulphate
Option (A)
Q.16) Ringelmann’s scale is used to :
A) Measure CO
B) Measure SO2
C) Grade density of smoke
D) Grade automobile exhaust gas
Option (C)
Explanation :
Ringelmann’s scale is a tool used to measure the opacity or density of smoke emitted from burning materials. The scale consists of five black squares of varying sizes, ranging from completely white (0) to completely black (5).
When smoke is present, an observer compares the color of the smoke to the squares on the Ringelmann chart to estimate its opacity. The observer chooses the square that most closely matches the color of the smoke, and this number corresponds to the smoke’s opacity level on the Ringelmann scale.
Q.17) Self-purification of running streams may be due to –
A) Sedimentation, oxidation and coagulation
B) Dilution, sedimentation and oxidation
C) Dilution, sedimentation and coagulation
D) Dilution, oxidation and coagulation
Option (B)
Q.18) The two main gases liberated from an anaerobic sludge digestion tank would include –
A) Ammonia and carbon dioxide
B) Carbon dioxide and methane
C) Methane and hydrogen sulphide
D) Ammonia and methane
Option (B)
Q.19) Which one of the following sewage treatment units has a parshall flume?
A) Trickling filter
B) Oxidation ditch
C) Grit chamber
D) Aerated lagoon
Option (C)
Q.20) The trap used for water closet is called –
A) Gully trap
B) P-trap
C) Intercepting trap
D) Anti-siphon trap
Option (B)
