Water Supply Engineering

71. Filtration of water is done to remove

1. Colour
2. Odour
3. Turbidity
4. Pathogenic bacteria

View answer

72. Flow through period, in sedimentation tanks, is

1. Equal to detention period
2. More than detention period
3. Less than detention period
4. Detention period divided by displacement efficiency

View answer

73. For 3.25 × 10-^-2 cumecs discharging from a well, a pump is installed to lift water against a total head of 30 m. The minimum required horse power, is

1. 10 H.P.
2. 15 H.P.
3. 18 H.P.
4. 20 H.P.

View answer

74. For a city developed haphazardly, the layout of distribution pipes preferred to, is

1. Ring system
2. Radial system
3. Grid iron system
4. Dead end system

View answer

75. For calculation of economical diameter D of a pipe in metres for a discharge Q to be pumped in cumecs, Lea suggested the empirical formula

1. D = 0.22 √Q
2. D = 1.22 √Q
3. D = 2.22 √Q
4. D = 3.22 √Q

View answer

76. For centrifugal pumps

1. Initial cost is low
2. Limited space is required
3. The discharge obtained is steady and non-pulsating
4. All the above

View answer

77. For complete stabilisation of organic matter in polluted water, it takes

1. 5 days
2. 10 days
3. 20 days
4. 30 days

View answer

78. For controlling algae, the most commonly used chemical, is

1. Copper sulphate
2. Alum
3. Lime
4. Bleaching powder

View answer

79. For determining the velocity of flow of underground water, the most commonly used nonempirical formula is

1. Darcy's formula
2. Slichter's formula
3. Hazen's formula
4. Lacy's formula

View answer

80. For estimating the run off of catchments, the mean value of the constant 'K' in the Khosla's formula Q_y = P_y - K (1.8 T_y + 32) is

1. 1.21
2. 1.23
3. 1.25
4. 1.27

View answer