### Civil Engineering - Water Supply Engineering MCQs Part 4

1. Pick up the correct statement from the following :

A.
For determination of small colour intensities, tintometer is generally used
B.
The odour of water sample is generally measured by a term called odour intensity
C.
The colour of water sample may be detected by Nessler tube
D.
Specific conductivity of water measures the amount of dissolved salt
E.
All the above.

2. Before constructing a dam, the factor to be considered for controlling sedimentation, is

A.
selection of dam site
B.
construction of check dams
C.
providing vegetation screens
D.
providing under-sluices in the dam
E.
All the above.

3. The process of passing water through beds of granular materials, is called

A.
screening
B.
sedimentation
C.
filtration
D.
none of these.

4. If Q is discharge is cubicmetres per sec and D is the economical diameter of the pipe. According to Lea

A.
D = 0.67 to 0.87 Q
B.
D = 0.77 to 0.97 Q
C.
D = 0.97 to 1.22 Q
D.
D = 1.22 to 1.33 Q.

5. Water to the consumers may be supplied from

A.
infiltration galleries connected to sump well
B.
infiltration well dug out on the banks of rivers
C.
ranney wells sunk to the water level
D.
all the above.

6. If the average daily demand of a city of 50, 000 population, is 20 m.l.d., the maximum daily demand is

A. 24 mld
B. 30 mld
C. 36 mld
D. 54 mld.

7. Recuperation test is carried out to determine

A. turbidity of water
B. pH value of water
C. yield of well
D. discharge from a well.

8. The discharge for the confined tube well is obtained from

A. Thiem's formula
B. Darcy's formula
C. Tolman's formula
D. Dupuits formula.

9. Pick up the correct statement from the following :

A. Air lift pumps are generally used for pumping water from deep wells
B. Jet pumps are generally used for pumping water from small wells
C. The hydraulic ram works on the principle of water hammer
D. Rotary pumps are provided cams which rotate in opposite direction
E. all the above.

10. Turbidity of water is expressed

A. in ppm
B. in numbers in an arbitrary scale
C. by pH value
D. by colour code.

11. The ratio of the maximum daily consumption to the average daily demand, is

A. 1.0
B. 1.2
C. 1.4
D. 1.6
E. 1.8

12. The ratio of discharge and plan area of a continuous flow type settling tank, is known

B. overflow
C. overflow rate
D. all the above.

13. Pick up the correct statement from the following :

A. At a particular speed of operation, the head produced decreases with the increase of discharge
B. At zero discharge, discharge valve remaining closed, the head developed is maximum which is known as shut-off head
C. At a particular speed the discharge at which efficiency of a pump is maximum, is known as normal discharge
D. The brake horse power required from the primemover to drive the pump, increases with the increase of discharge
E. all the above.

14. The maximum pressure to which a pipe is subjected to during its operation, is known

A. working pressure
B. design pressure
C. test pressure
D. pipe pressure
E. all the above.

15. To control the growth of algae in reservoirs, the compound which is used, is

A. bleaching powder
B. copper sulphate
C. lime solution
D. alum solution
E. all the above.

16. Pick up the wrong nominal internal diameter of cast iron (spun) pipes in mm from the following :

A. 300
B. 400
C. 500
D. 550
E. 600

17. Hardness of water can be removed by boiling if it is due to

A. calcium bicarbonates
B. calcium sulphates
C. calcium chloride
D. calcium nitrates.

18. A well is considered to be good if it is sunk into

A. Clay
B. Sand
C. Coarse gravel
D. Silt.

19. The nitrate concentration in domestic water supplies, is generally limited to

A. 10 ppm
B. 15 ppm
C. 25 ppm
D. 30 ppm
E. 45 ppm.

20. Sluice valves in main water supplies

A. are used to regulate the flow of water in pipes
B. are spaced about 5 km apart
C. are usually placed at the summits
D. all the above.

21. Dead storage of a reservoir of Q capacity generally provided for silt deposition during its life time, is generally kept

A. 1/8th Q
B. 1/6th Q
C. 1/5th Q
D. 1/4th Q
E. 1/3rd Q.

22. If the specific capacity of a well is 0.3183 x 10-3 per sec, the discharge from a well of 4 m diameter under a depression head of 4 m, is

A. 8 litres/sec
B. 10 litres/sec
C. 12 litres/sec
D. 14 litres/sec
E. 16 litres/sec.

23. The factor to be considered for the source of city water supply, is

A. quantity and quality of the available water
B. elevation of the source of water
C. general terrain intervening the area
D. all the above.

24. Pick up the correct statement from the following :

A. Domestic use of water is 50% of total consumption
B. Average consumption of commercial use of water is 25% of total consumption
C. Consumption of water on public use is 10% of total consumption
D. Waste water and leakage is 15% of total consumption
E. all the above.

25. Yield of a drainage basin is :

A. run off of the area expressed as instantaneous rate
B. average run off over a short period
C. total volume of water flowing annually
D. all the above.

26. Normal values of overflow rate for plain sedimentation tank using coagulants, is

A. 750 to 1000 litres/hr/m2
B. 1000 to 1250 litres/hr/m2
C. 1250 to 1500 litres/hr/m2
D. 1500 litres/hr/m2.

27. The formula Q = P - K[1.8T + 32] in which Q is runoff, P is annual rain fall in cm, T is mean annual temperature in centigrades and K is a constant, is known

A. Justin's formula
B. Khosla's formula
C. English formula
D. Vermule's formula.

28. The formula for pipe flows, suggested by, Hazen-William is

A.
B. V = 0.85 CH R0.63 . S0.54
C.
D. None of these.

29. While selecting the location of an intake for collecting surface water, the factor considered, is

A. The intake point should be near as far as possible to the treatment plant
B. The intake point should be in purer zone of the water source
C. The intake point should be upstream of the point of disposal of waste water
D. The intake point in meandering rivers should be on concave banks
E. All the above;

30. Aqueducts are generally designed

A. circular
B. rectangular
C. horse shoe section
D. all the above.

31. Gravity conduits

A. carry water under gravity
C. are carried on trestles in valleys and depressions
D. are carried through tunnels in deep cuttings
E. All the above.

32. Carbonates in water produce

A. temporary hardness
B. permanent hardness
C. acidity
D. alkanity.

33. Hardness of water is caused by

A. presence of soap lather
B. presence of chlorides and sulphates of sodium and potassium
C. presence of bicarbonates, sulphates or chlorides of calcium and magnesium
D. turbidity.

34. A slow sand filter is cleaned if its filter head is higher than

A. 10 cm to 20 cm
B. 20 cm to 40 cm
C. 40 cm to 70 cm
D. 70 cm to 120 cm
E. 120 cm to 150 cm.

35. A strainer type well sunk through three pervious layers intervened by three impervious aquicludes, draws water from

A. top most pervious layer
B. central pervious layer
C. lowest pervious layer
D. all the pervious layers.

36. The permissible amount of nitrites present in potable water, is

A. 10 ppm
B. 15 ppm
C. 20 ppm
D. 45 ppm
E. Nil.

37. Water having pH value as 6, is

A. alkaline
B. acidic
C. neutral
D. none of these.

38. Alum is chemically

A. Copper sulphate
B. Aluminium sulphate
C. Ferrous sulphate
D. Ferric sulphate.

39. If w is the weight of water per cubic metre, Q is the discharge in cubic metres per sec and H is the total head, the required water horse power of the pump, is

A.
B.
C.
D.
E. none of these.

40. Perched acquifers are generally found

A. on the surface of the ground
B. below the surface of the ground but above water table
C. below the water table
D. all the above.

41. Pickup the incorrect statement from the following :

A. The invert of pressure conduit is independent of the grade of the hydraulic gradient line
B. The pressure conduits may be taken uphill upto a maximum height of 8.3 m
C. Aqueducts and tunnels sections are generally kept circular
D. None of these.

42. Detention period of a settling tank is

A. average theoretical time required for water to flow through the tank
B. time required for flow of water to fill the tank fully
C. average time for which water is retained in tank
D. ratio of volume of basin of a sedimentation tank to the rate of flow
E. all the above.

43. Pick up the incorrect statement from the following :

A. Water disinfected with ozone is free from any odour
B. Ozone removes bacterias as well as colour and odour
C. ozonised water becomes tasteless
D. None of these.

44. The order of existence of three portions of water in a reservoir from the bottom to top is

A. useful storage + surcharge storage + dead storage
B. useful storage + dead storage + surcharge storage
C. dead storage + useful storage + surcharge storage
D. surcharge storage + useful storage + dead storage
E. none of these.

45. The approximate diameter of a water mains for supplying 7.2 mld with a velocity 1.2 m/sec, is

A. 24 cm
B. 26 cm
C. 28 cm
D. 30 cm
E. 32 cm.

46. The chlorine supply cylinders are generally kept at 38°C to 40°C to prevent

A. conversion into crystals
B. it from burning
C. it from explosion
D. none of these.

47. The capability of a soil mass of full width and depth to transmit water, is known

A. porosity
B. permeability
C. transmissibility
D. none of these.

48. Well treated water is generally supplied for

A. domestic use
B. commercial use
C. public use
D. waste water
E. all the above.

49. Non-pathogenic bacterias cause the following water borne disease,

A. cholera
B. typhoid
C. infections hepatitis
D. none of these.

50. Steel pipe are

A. suitable for withstanding high internal pressure
B. connected by riveted or welded joints
C. generally laid under ground and no expansion joint is required
D. likely to last 100 years under ordinary conditions
E. None of these.