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This set of Water and Wastewater Engineering Multiple Choice Questions & Answers (MCQs) focuses on Water And Wastewater Engineering Set 2
Q1 | If the depth of flow in a circular sewer is 1/4th of its diameter D, the wetted perimeter is
- ??????
- ??????
- ??????
- ????
Q2 | At the junction of sewers
- Top of smaller sewer is kept lower
- Top of larger sewer is kept lower
- Tops of both the sewers are at the same level
- None of these
Q3 | The sewage treatment units in which anaerobic decomposition of organic matter is used, arecalled
- Imhoff tanks
- Trickling filters
- Sludge sedimentation tanks
- None of these
Q4 | The sewer which received discharge from two or more main sewers, is known as
- A trunk sewer
- An outfall sewer
- A main sewer
- An intercepting sewer
Q5 | The grit and silt of the grit chambers, may not be used for
- Raising low lying areas by dumping
- Concreting
- Both (a) and (b)
- Neither (a) nor (b)
Q6 | For treating the sewage of a large city, you will recommend
- A sedimentation tank and an activated sludge treatment plant
- A plant consisting of Imhoff tanks with low rate trickling filters
- Sedimentation tanks with high rate trickling filters
- None of these
Q7 | Imhoff cone is used to measure
- Total organic solids
- Total solids
- Total in organic solids
- Settleable solids
Q8 | 1000 kg of sewage contains
- 0.112 kg in suspension
- 0.112 kg in solution
- 0.225 kg in solution
- Both (a) and (c) of above
Q9 | For the COD test of sewage, organic matter is oxidised by K2 Cr2O7 in the presence of
- H2SO4
- HNO3
- HCl
- None of these
Q10 | The sludge does not contain waste water from
- Bath rooms
- Wash basins
- Kitchen sinks
- Toilets
Q11 | In sewers the velocity of flow should not be
- More than the self-cleansing velocity
- Less than the self-cleansing velocity
- Less than 10 m/sec
- More than 20 m/sec
Q12 | In sewers the effect of scouring is more on
- Top side
- Bottom side
- Horizontal side
- All sides
Q13 | The sewer which resists sulphide corrosion, is
- Brick sewer
- Cast iron sewer
- R.C.C. sewer
- Lead sewer
Q14 | In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for adischarge Q, is
- Q/(B × D)
- Q/(L × D)
- Q/L
- Q/(B × L)
Q15 | The formula which accepts the value of rugosity coefficient n = 0.012 to be used in Manning'sformula, is given by
- Bazin
- Crimp and Bruges
- William-Hazen
- Kutter
Q16 | The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known
- Bio-Chemical Oxygen Demand (B.O.D.)
- Dissolved Oxygen (D.O.)
- Chemical Oxygen Demand (C.O.D.)
- None of these
Q17 | Water content of sewage is about
- 90%
- 95%
- 99%
- 9.90%
Q18 | Skimming tanks are
- Used to remove the grease and oil
- Those from which sludge is skimmed out
- Tanks provided with self-cleansing screens
- Improved version of grit chambers
Q19 | The most efficient cross-section of sewers in a combined sewerage system is
- ) Parabolic
- Circular
- Rectangular
- New egged
Q20 | The detention period for plain sedimentation water tanks, is usually
- 4 to 8 hours
- 8 to 16 hours
- 16 to 24 hours
- 24 to 36 hours
Q21 | The factor responsible for purification of sewage in river is
- Hydrology
- Dissolved oxygen in water
- Temperature
- All the above
Q22 | Hume steel pipes are
- Steel pipes
- Steel shell coated from inside with cement mortar
- Steel shell coated from outside with cement mortar
- Both (B) and (C)
Q23 | To maintain aerobic biological activity, the moisture content of the compost mass should beabout
- 45%
- 50%
- 55%
- 60%
Q24 | Pick up the correct statement from the following:
- The larger the sewer in size, more will be
- The smaller the sewer in size, less will be velocity
- The larger the sewer in size, no deposition will take place
- The larger the sewer in size, deposition will take place
Q25 | The pH value of sewage is determined with the help of
- Imhoff Cone
- Turbid meter
- Potentiometer
- None of these