McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Civil Engineering .
| 51. |
The normal value of over flow rates for plain primary sedimentation tanks, ranges between |
| A. | 25,000 to 35,000 litres/sqm/day |
| B. | 40,000 to 50,000 litres/sqm/day |
| C. | 50,000 to 60,000 litres/sqm/day |
| D. | 80,000 to 100,000 litres/sqm/day |
| Answer» B. 40,000 to 50,000 litres/sqm/day | |
| 52. |
Which one of the following statements regarding septic tanks is wrong? |
| A. | A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided |
| B. | The outlet invert level is kept 5 to 7.5 cm below the inlet invert level |
| C. | The minimum width of septic level is 90 cm |
| D. | The depth of tank is kept equal to its width |
| Answer» D. The depth of tank is kept equal to its width | |
| 53. |
In areas where rainy season is limited to a few months, the type of sewerage system recommended is |
| A. | Combined system |
| B. | Partially separate system |
| C. | Separate system |
| D. | None of these |
| Answer» C. Separate system | |
| 54. |
The rate of accumulation of sludge in septic tanks is recommended as |
| A. | 30 litres/person/year |
| B. | 25 litres/person/year |
| C. | 30 litres/person/month |
| D. | 25 litres/person/month |
| Answer» A. 30 litres/person/year | |
| 55. |
Dried sewage after treatment is used as |
| A. | Fertilizer |
| B. | Building material |
| C. | Chemical for lowering B.O.D. |
| D. | Base material for paints |
| Answer» A. Fertilizer | |
| 56. |
For drains up to 15 cumecs, the depth “d” and “B” width are related by |
| A. | d = 0.2 |
| B. | d = 0.5 B |
| C. | B = 0.2 d |
| D. | B = 0.5 d |
| Answer» B. d = 0.5 B | |
| 57. |
In areas where light rains are uniformly distributed throughout the year, the type of sewerage system to be adopted is |
| A. | Separate system |
| B. | Combined system |
| C. | Partially combined system |
| D. | None of these |
| Answer» B. Combined system | |
| 58. |
Self-cleansing velocity is |
| A. | Velocity at dry weather flow |
| B. | Velocity of water at flushing |
| C. | Velocity at which no accumulation remains in the drains |
| D. | Velocity of water in a pressure filter |
| Answer» C. Velocity at which no accumulation remains in the drains | |
| 59. |
5 days-biochemical oxygen demand (BOD5) is taken at a temperature of |
| A. | 0°C |
| B. | 15°C |
| C. | 20°C |
| D. | 25°C |
| Answer» C. 20°C | |
| 60. |
A well oxidized sewage contains nitrogen mainly as |
| A. | Nitrates |
| B. | Nitrites |
| C. | Free ammonia |
| D. | None of these |
| Answer» A. Nitrates | |
| 61. |
In a sludge tank, the gas mainly produced, is |
| A. | Oxygen |
| B. | Nitrogen |
| C. | Hydrogen |
| D. | Carbon dioxide |
| Answer» D. Carbon dioxide | |
| 62. |
If “D” is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section, is |
| A. | 1.250 D |
| B. | 1.350 D |
| C. | 1.425 D |
| D. | 1.625 D |
| Answer» D. 1.625 D | |
| 63. |
In normal conditions, the period for sludge digestion, is |
| A. | 10 days |
| B. | 20 days |
| C. | 30 days |
| D. | 60 days |
| Answer» C. 30 days | |
| 64. |
For evaporation and measurement of settable solids, the apparatus used, is |
| A. | A jar |
| B. | A breaker |
| C. | A test tube |
| D. | An Imhoff cone |
| Answer» D. An Imhoff cone | |
| 65. |
In trickling filter, B.O.D. is reduced to |
| A. | 30 to 40% |
| B. | 40 to 60% |
| C. | 60 to 80% |
| D. | 80 to 90% |
| Answer» C. 60 to 80% | |
| 66. |
For design of sewers, percentage of sewage discharge is assumed |
| A. | 65 to 70 |
| B. | 70 to 75% |
| C. | 75 to 80% |
| D. | 85% |
| Answer» C. 75 to 80% | |
| 67. |
The grit chambers of sewage treatment plants, are generally cleaned after |
| A. | 2 days |
| B. | 7 days |
| C. | 12 days |
| D. | 14 days |
| Answer» D. 14 days | |
| 68. |
Maximum permissible velocity 1.5 m/sec, is adopted in drains |
| A. | With beds of rocks and gravels |
| B. | Lined with stones |
| C. | Both (a) and (b) |
| D. | Neither (a) nor (b) |
| Answer» C. Both (a) and (b) | |
| 69. |
The average temperature of sewage in India, is |
| A. | 10°C (B) (C) (D) |
| B. | 15°C |
| C. | 20°C |
| D. | 25°C |
| Answer» C. 20°C | |
| 70. |
Pick up the in-correct statement from the following: |
| A. | Manholes are provided in sewer pipes at suitable intervals |
| B. | Catch basins are generally provided in sewers for carrying drainage discharge |
| C. | Inlets are generally provided in all sewers |
| D. | None of these |
| Answer» C. Inlets are generally provided in all sewers | |
| 71. |
The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is |
| A. | 25 % (B) (C) (D) |
| B. | 50 % |
| C. | 10 % |
| D. | 5 % |
| Answer» B. 50 % | |
| 72. |
If ‘D’ is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section, is |
| A. | 1.250 D |
| B. | 1.350 D |
| C. | 1.425 D |
| D. | 1.625 D |
| Answer» D. 1.625 D | |
| 73. |
In trickling filter, B.O.D. is reduced to |
| A. | 30 to 40% (B) (C) (D) |
| B. | 40 to 60% |
| C. | 60 to 80% |
| D. | 80 to 90% |
| Answer» C. 60 to 80% | |
| 74. |
For design of sewers, percentage of sewage discharge is assumed |
| A. | 65 to 70% (B) (C) (D) |
| B. | 70 to 75% |
| C. | 75 to 80% |
| D. | 85% |
| Answer» C. 75 to 80% | |
| 75. |
The grit chambers of sewage treatment plants, are generally cleaned after |
| A. | 2 days (B) (C) (D) |
| B. | 7 days |
| C. | 12 days |
| D. | 14 days |
| Answer» D. 14 days | |
| 76. |
In the activated sludge process |
| A. | Aeration is continued till stability |
| B. | Aeration is done with an admixture of previously aerated sludge |
| C. | Sludge is activated by constant stirring |
| D. | Water is removed by centrifugal action |
| Answer» B. Aeration is done with an admixture of previously aerated sludge | |
| 77. |
For detecting the nitrates in sewage, the colour may be developed by adding |
| A. | Potassium permanganate (B) (C) (D) |
| B. | Sulphuric acid and napthamine |
| C. | Phenol-di-sulphuric acid and potassium hydroxide |
| D. | None of these |
| Answer» C. Phenol-di-sulphuric acid and potassium hydroxide | |
| 78. |
The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock's law, is |
| A. | Vs = 418 (Gs- Gw)d [(3T + 70)/100] |
| B. | Vs = 418 (Gs - Gw)d² [(3T + 70)/100] |
| C. | Vs = 218 (Gs - Gw)d² [(3T + 70)/100] |
| D. | Vs = 218 (Gs - Gw)d [(3T + 70)/100] |
| Answer» B. Vs = 418 (Gs - Gw)d² [(3T + 70)/100] | |
| 79. |
Inter-distance between ventilation columns in a sewer line is kept |
| A. | 25 to 50 m |
| B. | 50 m to 100 m |
| C. | 100 m to 150 m |
| D. | 150 m to 300 m |
| Answer» D. 150 m to 300 m | |
| 80. |
Stone ware pipes are |
| A. | Highly resistant to sulphide corrosion (B) (C) (D) |
| B. | Highly impervious |
| C. | Hydraulically efficient because of their smooth interior surface |
| D. | Especially suited to pressure pipes |
| Answer» D. Especially suited to pressure pipes | |
| 81. |
The intensity of rain is expressed in |
| A. | cm/minute (B) (C) (D) |
| B. | cm/hour |
| C. | cm/day |
| D. | None of these |
| Answer» B. cm/hour | |
| 82. |
The ratio of the diameter of a circular section and the side of a square section hydraulically equivalent, is |
| A. | 1.095 |
| B. | 1.085 |
| C. | 1.075 |
| D. | 1.065 |
| Answer» A. 1.095 | |
| 83. |
Which one of the following part of human body withstands minimum radiation? |
| A. | Thyroid |
| B. | Kidneys |
| C. | Eyes |
| D. | Ovaries/testis |
| Answer» D. Ovaries/testis | |
| 84. |
Drop manholes are the manholes |
| A. | Without entry ladders |
| B. | Without manhole covers |
| C. | With depths more than 3.5 m |
| D. | Having drains at different levels |
| Answer» D. Having drains at different levels | |
| 85. |
The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope |
| A. | 1 in 5 |
| B. | 1 in 10 |
| C. | 1 in 15 |
| D. | 1 in 20 |
| Answer» B. 1 in 10 | |
| 86. |
Primary treatment of sewage consists of removal of |
| A. | Large suspended organic solids |
| B. | Oil and grease |
| C. | Sand and girt |
| D. | Floating materials |
| Answer» A. Large suspended organic solids | |
| 87. |
Cement concrete sewers are only suitable if non-scouring velocity is between |
| A. | ) 2.5 to 3.0 m/sec (B) (C) (D) |
| B. | 3.0 to 4.0 m/sec |
| C. | 3.5 to 4.5 m/sec |
| D. | 4.5 to 5.5 m/sec |
| Answer» A. ) 2.5 to 3.0 m/sec (B) (C) (D) | |
| 88. |
The most widely used pump for lifting sewage is |
| A. | Centrifugal pump |
| B. | Reciprocating pump |
| C. | Pneumatic ejector |
| D. | Air pressure pump |
| Answer» A. Centrifugal pump | |
| 89. |
Setting out the alignments of sewers may start from |
| A. | City |
| B. | Out-fall |
| C. | Tail end |
| D. | Any point |
| Answer» C. Tail end | |
| 90. |
The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is |
| A. | d² (0.011d + 0.785H)/Q |
| B. | d (0.022d + 0.085H)/Q |
| C. | d (0.785d + 0.011H)/Q |
| D. | d (0.285d + 0.011H)/Q |
| Answer» A. d² (0.011d + 0.785H)/Q | |
| 91. |
Lead acetate test in sewer manhole is done to test the presence of |
| A. | Methane gas (B) (C) (D) |
| B. | Hydrogen sulphide |
| C. | Carbondioxide gas |
| D. | Diesel vapours |
| Answer» B. Hydrogen sulphide | |
| 92. |
Anti syphonage pipe is fitted |
| A. | At the end of septic tanks (B) (C) (D) |
| B. | On manholes |
| C. | With a W.C. trap |
| D. | At the beginning of sewer line |
| Answer» C. With a W.C. trap | |
| 93. |
In a grit chamber of a sewage treatment plant, |
| A. | Flow velocity 0.15 m to 0.3 m/sec is kept |
| B. | Depth of 0.9 m to 1.20 m is kept |
| C. | One minute of detention period is kept |
| D. | All the above |
| Answer» D. All the above | |
| 94. |
The ratio of maximum sewage flow to average sewage flow for mains up to 1 m in diameter, is |
| A. | 1.5 (B) (C) (D) |
| B. | 2.0 |
| C. | 3.0 |
| D. | 4.0 |
| Answer» B. 2.0 | |
| 95. |
pH value of sludge during alkaline regression stage, is |
| A. | More than 7 |
| B. | Less than 7 |
| C. | Less than 6 |
| D. | More than 6 |
| Answer» A. More than 7 | |
| 96. |
The arrangement made for passing the sewer line below an obstruction below the hydraulic gradient lines called |
| A. | Inverted syphon |
| B. | Depressed sewer |
| C. | Sag pipe |
| D. | all of these |
| Answer» D. all of these | |
| 97. |
Pick up the incorrect size of stone ware sewers |
| A. | 52.5 cm (B) (C) (D) |
| B. | 67.5 cm |
| C. | 82.5 cm |
| D. | None of these |
| Answer» D. None of these | |
| 98. |
Chlorination of water is done for the removal of |
| A. | Bacterias |
| B. | Suspended solids |
| C. | Sediments |
| D. | Hardness |
| Answer» A. Bacterias | |
| 99. |
Sludge banks are formed if sewage is disposed of in |
| A. | Rivers |
| B. | Seas |
| C. | Lakes |
| D. | None of these |
| Answer» B. Seas | |
| 100. |
The clarigesters are |
| A. | Circular septic tanks |
| B. | Rectangular septic tanks |
| C. | Circular Imhoff double tanks with bottom hoppers |
| D. | Circular Imhoff double storey tanks without bottom hoppers |
| Answer» D. Circular Imhoff double storey tanks without bottom hoppers | |
Done Studing? Take A Test.
Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.