Public Health Engineering 3

 41.The presence of sodium chloride in water ?

• causes bad taste 
• softens the water 
• increases hardness of water 
• stops epidemic 

42.Turbidity of water is expressed in terms of ?

• silica scale 
• platinum cobalt scale 
• no value 
• none of these 

43.The most important source of water for public water supply is ?

• lake 
• pond 
• river 
• sea 

44.The yield of a underground source may be obtained by ?

• pumping test 
• recupating test 
• both (a) and (b) 
• none of these 

45.The water bearing strata i.e. layers of sand, gravel etc. is called ?

• an acquifer 
• an aquiclude 
• an aquifuge 
• zone of saturation 

46.The design period for a water supply project is taken as ?

• 5 to 10 years 
• 10 to 15 years 
• 15 to 20 years 
• 20 to 30 year 

47.The water supply system means ?

• the entire scheme of collection and disposal of liquid waste 
• the complete layout from the source of supply to the distribution 
• construction of reservoirs 
• construction of canals 

48.Which of the following statement is correct ?

• If the pH value of water is equal to 7, the water is said to be neutral 
• The pH value determines the strength of the acid or alkali in water 
• The pH value of water can be obtained by a potentiometer 
• all of the above 

49.The portion of soil through which lateral movement of water take place is ?

• water table 
• an aquiclude 
• zone of saturation 
• none of these 

50.When in the previous strata, the surface of water surrounding the well is at atmospheric pressure, well is known as ?

• gravity well 
• artesian well 
• open well 
• deep well

51.Suspended impurities include ?

• algae 
• protozoa 
• fungi 
• all of these 

52.Odours and tastes may result due to the presence of ?

• micro-organisms either dead or alive 
• dissolved gases such as oxygen, carbon dioxide, methane etc 
• mineral substances such as sodium chloride, iron compounds etc 
• all of the above 

53.The water obtained from .............. is generally known as sub-surface water ?

• rains 
• rivers 
• reservoirs 
• artesian well 

54.pH value is a symbol for .......... concentration ?

• magnesium 
• hydrogen 
• calcium 
• sodium 

55.In designing a water works for a city to meet the water demand for public use,a precision about ............... of the total consumption is made ?

• 5 % 
• 10 % 
• 20 % 
• 25 % 

56.The presence of bacteria in water causes ?

• hardness 
• alkalinity 
• diseases 
• bad taste 

57.In India, as per Indian standards, water consumption per capita per day for domestic purpose is ?

• 85 litres 
• 100 litres 
• 115 litres 
• 135 litres 

58.The water obtained from the tube wells is known as ?

• surface water 
• sub-surface water 
• run-off 
• potable water 

59.The water of a river has an important property called ?

• turbidity 
• self purification 
• permeability 
• infiltration capacity 

60.The open wells or dug wells are also known as ?

• shallow wells 
• draw wells 
• percolation wells 
• all of these.

61.The horizontal tunnels constructed at shallow depths along the banks of a river to intern ground water table are called ?

• canals 
• infiltration galleries 
• springs 
• lakes 

62.Which of the following formula is used for computing the quantity of water for fire demand ?

• Freeman's formula 
• Kuichling formula 
• Buston's formula 
• all of these 

63.Which of the following statement is correct ?

• The sub-surface sources are not affected by draught 
• Infiltration galleries are most suitable for increasing the surface source supply, in dry season 
• The rate at which water percolates into well under safe maximum critical depression head is called yield of well 
• all of the above 

64.The domestic use of water amounts to ............ of the total water requirements per capita per ?

• 20% 
• 30% 
• 40% 
• 50% 

65.The vertical wells provided along the banks of a river to draw ground water in dry season are called ?

• open wells 
• tube wells 
• artesian wells 
• infiltration wells 

66.The presence of hydrogen sulphide in water causes ?

• softening 
• alkalinity 
• acidity 
• bad taste 

67.A pipe sunk into the ground to tap the underground water is called ?

• open well 
• tube well 
• artesian well 
• infiltration well 

68.The presence of calcium and magnesium chloride in water causes ?

• softening 
• bad taste 
• hardness 
• turbidity 

69.The earth's water circulatory system is known as ?

• water cycle 
• hydrological cycle 
• precipitation cycle 
• all of these 

70.The growth of population may be conveniently represented by ?

• semi-logarthmic curve 
• logistic curve 
• straight line curve 
• all of these.