On This Page
This set of Water and Wastewater Engineering Multiple Choice Questions & Answers (MCQs) focuses on Water And Wastewater Engineering Set 5
Q1 | The spacing of bars for perforations in coarse screens used for the treatment of sewage, is
- 20 mm
- 30 mm
- 40 mm
- 50 mm
Q2 | The pH value of fresh sewage is usually
- Equal to 7
- More than 7
- Less than 7
- Equal to zero
Q3 | The maximum depth of sedimentation tanks, is kept
- 3 m
- 3.5 m
- 4 m
- 4.5 m
Q4 | Lead caulked joints are used for laying
- Stone ware pipes
- Earthenware pipes
- C.I. pipes
- G.I. pipes
Q5 | If D is the diameter of a circular sewer and D' is the top horizontal diameter of an equivalent eggshaped section, the relationship which holds good, is
- D' = 0.64 D
- D' = 0.74 D
- D' = 0.84 D
- D' = 0.94 D
Q6 | The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewermay be
- 0.9 cm
- 1.2 m
- 1.5 m
- > 1.5 m
Q7 | The quantity of liquid waste which flows in sewers during the period of rainfall, is known
- Sanitary sewage
- Industrial waste
- Storm sewage
- None of these
Q8 | Nitrogen cycle of sewage, is
- Liberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen
- Liberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates
- Liberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia
- Formation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates
Q9 | Depletion of ozone layer in the outer atmosphere may cause
- Lung cancer
- Skin cancer
- Bronchitis
- Heart disorder
Q10 | The minimum diameter of a sewer is kept
- 10 cm
- 15 cm
- 20 cm
- 25 cm
Q11 | Which one of the following gases is most significant as air pollutant?
- Carbondioxide (B) (C) (D)
- Oxygen
- Nitrogen
- Sulphur-dioxide
Q12 | Hazen's formula VS = 418 (GS - Gw)d [(3T + 70)/100] is used for the settlement velocity of theparticles of diameter
- Less than 0.01 mm
- Less than 0.05 mm
- Less than 0.1 mm
- Greater than 0.1 mm
Q13 | For sewers, inverted siphon is provided for
- One pipe
- Two pipes
- Three pipes
- Four pipes
Q14 | For large sewers, maximum distance between manholes may be
- 50 m
- 100 m
- 200 m
- 300 m
Q15 | In sewers designed with self cleansing velocity,
- The bottom is silted
- The bottom is scoured
- Both silting and scouring occur at the bottom
- Neither silting nor scouring occurs at the bottom
Q16 | The value of Chezy's constant C = 157.6/(1.81 + K/ ?? ) is used in
- Chezy's formula
- Bazin's formula
- Kutter's formula
- Manning's formula
Q17 | Pathogens (or pathogenic bacteria’s) in water may cause
- Typhoid
- Cholera
- Dysentery
- All the above
Q18 | The rate of accumulation of sludge per person per year, is
- 10 litres (B) (C) (D)
- 15 litres
- 20 litres
- 25 litres
Q19 | The screens are fixed
- Perpendicular to the direction of flow
- Parallel to the direction of flow
- At an angle 30° to 60° to the direction of flow
- None of these
Q20 | In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient,
- Is only provided
- Is doubled
- Is trebled
- Is not enough
Q21 | In detritus tanks
- Flow velocity is kept 0.09 m/
- Detention period is kept 3 to 4 minutes
- Organic and inorganic materials are separated
- All the above
Q22 | The flow velocity in detritus tanks is
- 0.05 m/sec
- 0.09 m/sec
- 1.25 m/sec
- None of these
Q23 | If the side of a square sewer is 1000 mm, the diameter of a hydraulically equivalent circularsection, is
- 1045 mm
- 1065 mm
- 1075 mm
- 1095 mm
Q24 | A nuisance is experienced in diluting water if dilution factor is less than
- 100
- 60
- 40
- 20
Q25 | A manhole is generally provided at each
- Bend
- Junction
- Change of gradient
- All the above