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This set of Water and Wastewater Engineering Multiple Choice Questions & Answers (MCQs) focuses on Water And Wastewater Engineering Set 9
Q1 | After cleaning a slow sand filter, the filtered water is not used for
- 6 hours to 12 hours
- 12 hours to 18 hours
- 18 hours to 24 hours
- 24 hours to 36 hours
Q2 | The efficiency of sedimentation tank does not depend upon
- Depth of tank
- Length of tank
- Detention period
- Velocity of water
Q3 | Velocity of flow of water in plain sedimentation water tank, is normally kept
- 3 cm/minute
- 10 cm/minute
- 20 cm/minute
- 30 cm/minute
Q4 | The depth of the water table at a place is 45 m below the general ground level. To lift waterfrom a deep tube well in such a locality, the type of pump to be installed is
- Centrifugal pump
- Reciprocating pump
- Deep well turbine pump
- None of these
Q5 | In a well planned city, the layout of distribution pipes generally adopted, is
- Grid-iron system
- Interlaced system
- Reticulation system
- All the above
Q6 | Pick up the incorrect statement from the following:
- Free surface ground water is subjected to atmospheric pressure
- Water table surface rises and falls with seasons
- Depth of water table is directly proportional to the rate of drawl of water
- Level of water table remains stationary
Q7 | Pick up the incorrect statement from the following:
- The flow in strainer type wells is radial (B) (C) (D)
- The flow in cavity type wells in spherical
- In strainer type wells, area of flow depends upon the length of the strainer pipe
- In cavity type wells, area of flow depends upon the size of the cavity
Q8 | As per IS : 1172-1963, water required per head per day for average domestic purposes, is
- 50 litres
- 65 litres
- 85 litres
- 135 litres
Q9 | The duration of contact of chlorine with water before it is served to the first consumer, shouldbe at least
- 10 to 15 minutes
- 15 to 20 minutes
- 20 to 30 minutes
- 30 to 40 minutes
Q10 | Water supply system includes
- Digging a well for water
- Construction of dams
- Construction of canals
- Entire arrangement from source to distribution
Q11 | The maximum pressure to which a pipe is subjected to during its operation, is known
- Working pressure
- Design pressure
- Test pressure
- Pipe pressure
Q12 | For the same draw down in two observations wells at distances r1 and r2, the times after startof pumping are t1 and t2 hours respectively. The relation which holds good is
- t2 = r2/r1 × t1
- t2 = (r2/r1)² × t1
- t2 = (r2/r1)3× t1
- t2 = (r2/r1) × t12
Q13 | A slow sand filter is cleaned if its filter head is higher than
- 10 cm to 20 cm
- 20 cm to 40 cm
- 40 cm to 70 cm
- 70 cm to 120 cm
Q14 | The intake opening is generally covered by a screen to prevent entry of debris etc. and its levelis kept
- At the level of water of the source
- At the bottom of water of the source
- At about 2.5 m above the bottom
- None of these
Q15 | If four fires break out in a city of population 40 lakhs and if each hydrant has three streams andduration of each fire is four hours, the total quantity of water required, is
- 1880 kilo litres
- 2880 kilo litres
- 3880 kilo litres
- 4880 kilo litres
Q16 | Steel pipe are
- Suitable for withstanding high internal pressure
- Connected by riveted or welded joints
- Generally laid underground and no expansion joint is required
- Likely to last 100 years under ordinary conditions
Q17 | When gravity and pumping systems of water distribution are adopted, the type of distributionreservoir, is
- Elevated tank
- Ground source reservoir
- Intz tank
- Stand pipe
Q18 | The force which develops in a pressure conduit supported on trestles, is
- Tension
- Compression
- Temperature stress
- Flexural stress
Q19 | Standard unit of turbidity of water is in one litre of distilled water, one milligram of finelydivided
- Silica
- Mud
- Clay
- Organic matter
Q20 | For complete stabilisation of organic matter in polluted water, it takes
- 5 days
- 10 days
- 20 days
- 30 days
Q21 | If intensity of rainfall in cm per hour is I, percentage coefficient of run-off is P, area of catchmentin square kilometres is A, the total run-off Q, is given by
- Q = 1.758 × 102× API (B) (C) (D)
- Q = 2.758 × 102× API
- Q = 2.758 × 103× API
- Q = 2.758 × 103× A/PI
Q22 | Shales are
- Porous
- Permeable
- Porous and permeable
- Porous but not permeable
Q23 | The best process of disinfection of public water supply, is by
- Boiling
- Chlorination
- Adding lime
- Adding ozone
Q24 | The dilution ratio at which the odour is hardly detectable is generally called threshold odournumber and for public supplies it should not exceed
- 3
- 5
- 7
- 9
Q25 | Surge tanks are used
- For storage water
- To increase the velocity in a pipeline
- As overflow valves
- To guard against water hammer