MCQOPTIONS
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MCQOPTIONS
This section includes 238 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The most common cause of acidity in water is_______________? |
| A. | carbon dioxide |
| B. | oxygen |
| C. | hydrogen |
| D. | nitrogen |
| Answer» B. oxygen | |
| 52. |
The minimum dissolved oxygen which should always be present in water in order to save the aquatic life is______________? |
| A. | 1 ppm |
| B. | 4 ppm |
| C. | 10 ppm |
| D. | 40 ppm |
| Answer» C. 10 ppm | |
| 53. |
The minimum and maximum diameters of sewers shall preferably be_________________? |
| A. | 15 cm and 100 cm |
| B. | 15 cm and 300 cm |
| C. | 30 cm and 450 cm |
| D. | 60 cm and 300cm |
| Answer» C. 30 cm and 450 cm | |
| 54. |
The method of analysis of distribution system in which the domestic supply is neglected and fire demand is considered is________________? |
| A. | circle method |
| B. | equivalent pipe method |
| C. | electrical analysis method |
| D. | Hardy cross method |
| Answer» B. equivalent pipe method | |
| 55. |
The means of access for inspection and cleaning of sewer line is known as_______________? |
| A. | inlet |
| B. | manhole |
| C. | drop manhole |
| D. | catch basin |
| Answer» C. drop manhole | |
| 56. |
The maximum permissible limit for flouride in drinking water is______________? |
| A. | 0.1 mg/litre |
| B. | 1.5 mg/litre |
| C. | 5 mg/litre |
| D. | 10 mg/litre |
| Answer» C. 5 mg/litre | |
| 57. |
The maximum efficiency of BOD removal is achieved in______________? |
| A. | oxidation pond |
| B. | oxidation ditch |
| C. | aerated lagoons |
| D. | trickling filters |
| Answer» C. aerated lagoons | |
| 58. |
The maximum discharge of a tube-well is about_________________? |
| A. | 5 litres/sec |
| B. | 50 litres/sec |
| C. | 500 litres/sec |
| D. | 1000 litres/see |
| Answer» C. 500 litres/sec | |
| 59. |
The major disadvantage of lime soda process of water softening is that_________________? |
| A. | it is unsuitable for turbid and acidic water |
| B. | huge amount of precipitate is formed which creates a disposal problem |
| C. | the effluent cannot be reduced to zero hardness |
| D. | it is unsuitable for softening the water of excessive hardness |
| Answer» C. the effluent cannot be reduced to zero hardness | |
| 60. |
The main disadvantage of cement concrete sewers is________________? |
| A. | less strength |
| B. | difficulty in construction |
| C. | difficulty in transportation due to heavy weight |
| D. | less life |
| Answer» D. less life | |
| 61. |
The main disadvantage of oxidation pond is that________________? |
| A. | large area is required for construction |
| B. | maintenance and operation cost are high |
| C. | BOD removal is very low |
| D. | none of the above |
| Answer» B. maintenance and operation cost are high | |
| 62. |
The length of rectangular sedimentation tank should not be more than_______________? |
| A. | B |
| B. | 2B |
| C. | 4B |
| D. | 8B |
| Answer» D. 8B | |
| 63. |
The layout of distribution system in which water flows towards the outer periphery is_________________? |
| A. | ring system |
| B. | dead end system |
| C. | radial system |
| D. | grid iron system |
| Answer» D. grid iron system | |
| 64. |
The hydraulic mean depth (HMD. for an egg-shaped sewer flowing two-third full is_______________? |
| A. | equal to HMD when flowing full |
| B. | less than HMD when flowing full |
| C. | greater than HMD when flowing full |
| D. | none of the above |
| Answer» D. none of the above | |
| 65. |
The hourly variation factor is usually taken as______________? |
| A. | 1.5 |
| B. | 1.8 |
| C. | 2.0 |
| D. | 2.7 |
| Answer» B. 1.8 | |
| 66. |
The gas from sludge digestion tank is mainly composed of __________________? |
| A. | nitrogen |
| B. | carbon dioxide |
| C. | hydrogen sulphide |
| D. | methane |
| Answer» E. | |
| 67. |
The effective size of sand particles used in slow sand filters is_______________? |
| A. | 0.25 to 0.35 mm |
| B. | 0.35 to 0.60 mm |
| C. | 0.60 to 1.00 mm |
| D. | 1.00 to 1.80 mm |
| Answer» B. 0.35 to 0.60 mm | |
| 68. |
The effect of increasing diameter of sewer on the self cleansing velocity is_____________? |
| A. | to decrease it |
| B. | to increase it |
| C. | fluctuating |
| D. | nil |
| Answer» C. fluctuating | |
| 69. |
The distribution mains are designed for________________? |
| A. | maximum daily demand |
| B. | maximum hourly demand |
| C. | average daily demand |
| D. | maximum hourly demand on maxi¬mum day |
| Answer» E. | |
| 70. |
The dissolved oxygen level in natural unpolluted waters at normal temperature is found to be of the order of________________? |
| A. | 1 mg/litre |
| B. | 10 mg/litre |
| C. | 100 mg/litre |
| D. | 1000 mg/litre |
| Answer» C. 100 mg/litre | |
| 71. |
The disinfection efficiency of chlorine increases by_______________?_x005F_x000D_1) decreasing the time of contact_x005F_x000D_2) decreasing the temperature of water_x005F_x000D_3) increasing the temperature of water_x005F_x000D_The correct answer is ? |
| A. | only (1) |
| B. | both (1) and (2) |
| C. | both (1) and (3) |
| D. | only (3) |
| Answer» E. | |
| 72. |
The devices which are installed for drawing water from the sources are called______________? |
| A. | aquifers |
| B. | aquiclude |
| C. | filters |
| D. | intakes |
| Answer» E. | |
| 73. |
The detention period in coagulation tanks is usually kept as_______________? |
| A. | 1 to 2 minutes |
| B. | 30 to 45 minutes |
| C. | 2 to 6 hours |
| D. | 2 to 6 days |
| Answer» D. 2 to 6 days | |
| 74. |
The detention period for oxidation ponds is usually kept as______________? |
| A. | 4-8 hours |
| B. | 24 hours |
| C. | 10 to 15 days |
| D. | 3 months |
| Answer» D. 3 months | |
| 75. |
The detention period and overflow rate respectively for plain sedimentation as compared to sedimentation with coagulation are generally_______________? |
| A. | less and more |
| B. | less and less |
| C. | more and less |
| D. | more and more |
| Answer» D. more and more | |
| 76. |
The design discharge for the combined sewer system shall be taken as________________? |
| A. | equal to rainfall |
| B. | rainfall + DWF |
| C. | rainfall + 2 DWF |
| D. | rainfall + 6 DWF |
| Answer» D. rainfall + 6 DWF | |
| 77. |
The design discharge for the separate sewer system shall be taken as_____________? |
| A. | equal to dry weather flow (DWF) |
| B. | 2xDWF |
| C. | 3 x DWF |
| D. | 6xDWF |
| Answer» E. | |
| 78. |
The depression of water table in a well due to pumping will be maximum_______________? |
| A. | at a distance R from the well |
| B. | close to the well |
| C. | at a distance R/2 from the well |
| D. | none of the above |
| Answer» C. at a distance R/2 from the well | |
| 79. |
The correct relation between theoretical oxygen demand (TOD), Biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) is given by_______________? |
| A. | TOD>BOD>COD |
| B. | TOD>COD>BOD |
| C. | BOD>COD>TOD |
| D. | COD>BOD>TOD |
| Answer» C. BOD>COD>TOD | |
| 80. |
The chemical most commonly used to increase speed of sedimentation of sewage is_______________? |
| A. | sulphuric acid |
| B. | copper sulphate |
| C. | lime |
| D. | sodium permanganate |
| Answer» D. sodium permanganate | |
| 81. |
The characteristics of fresh and septic sewage respectively are____________________? |
| A. | acidic and alkaline |
| B. | alkaline and acidic |
| C. | both acidic |
| D. | both alkaline |
| Answer» C. both acidic | |
| 82. |
The amount of residual chlorine left in public water supply for safety against pathogenic bacteria is about______________? |
| A. | 0.01 to 0.05 ppm |
| B. | 0.05 to 0.5 ppm |
| C. | 0.5 to 1.0 ppm |
| D. | 1.0 to 5.0 ppm |
| Answer» C. 0.5 to 1.0 ppm | |
| 83. |
The amount of coagulant needed for coagulation of water increases with_______________?_x005F_x000D_1) increase in turbidity of water_x005F_x000D_2) decrease in turbidity of water_x005F_x000D_3) increase in temperature of water_x005F_x000D_4) decrease in temperature of water_x005F_x000D_The correct answer is? |
| A. | (1) and (2) |
| B. | (1)and (4) |
| C. | (2) and (3) |
| D. | (2) and (4) |
| Answer» C. (2) and (3) | |
| 84. |
The alum, when added as a coagulant in water_______________? |
| A. | does not require alkalinity in water for flocculation |
| B. | does not affect pH value of water |
| C. | increases pH value of water |
| D. | decreases pH value of water |
| Answer» E. | |
| 85. |
Scour valves are provided ______________? |
| A. | at street corners to control the flow of water |
| B. | at every depression and dead ends to drain out the waste water that may collect there |
| C. | at the foot of rising main along the slope to prevent back running of water |
| D. | at every summit of rising mains |
| Answer» C. at the foot of rising main along the slope to prevent back running of water | |
| 86. |
Residual chlorine in water is determined by________________? |
| A. | starch iodide method |
| B. | orthotolidine method |
| C. | both (A) and (B) |
| D. | none of the above |
| Answer» D. none of the above | |
| 87. |
Period of cleaning of slow sand filters is about________________? |
| A. | 24 – 48 hours |
| B. | 10-12 days |
| C. | 2-3 months |
| D. | 1-2 year |
| Answer» D. 1-2 year | |
| 88. |
Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about_______________? |
| A. | 10 to 25 |
| B. | 50 |
| C. | 75 |
| D. | 100 |
| Answer» D. 100 | |
| 89. |
Orthotolidine test is used for determination of________________? |
| A. | dissolved oxygen |
| B. | residual chlorine |
| C. | biochemical oxygen demand |
| D. | dose of coagulant |
| Answer» C. biochemical oxygen demand | |
| 90. |
On standard silica scale, the turbidity in drinking water should be limited to_______________? |
| A. | 10 ppm |
| B. | 20 ppm |
| C. | 30 ppm |
| D. | 50 ppm |
| Answer» B. 20 ppm | |
| 91. |
Most suitable section of sewer in separate sewage system is________________? |
| A. | rectangular section |
| B. | circular section |
| C. | standard form of egg shaped sewer |
| D. | modified egg shaped section |
| Answer» C. standard form of egg shaped sewer | |
| 92. |
Most of the bacteria in sewage are______________? |
| A. | parasitic |
| B. | saprophytic |
| C. | pathogenic |
| D. | anaerobic |
| Answer» C. pathogenic | |
| 93. |
Laying of sewers is usually done with the help of________________? |
| A. | a theodolite |
| B. | a compass |
| C. | sight rails and boning rods |
| D. | a plane table |
| Answer» D. a plane table | |
| 94. |
In water treatment, rapid gravity filters are adopted to remove_______________? |
| A. | dissolved organic substances |
| B. | dissolved solids and dissolved gases |
| C. | floating solids and dissolved inorganic solids |
| D. | bacteria and colloidal solids |
| Answer» E. | |
| 95. |
In lime-soda process________________? |
| A. | only carbonate hardness is removed |
| B. | only non-carbonate hardness is re-moved |
| C. | lime reduces the carbonate hardness and soda-ash removes the non-carbo¬nate hardness |
| D. | lime reduces the non-carbonate hard-ness and soda-ash removes the carbo¬nate hardness |
| Answer» D. lime reduces the non-carbonate hard-ness and soda-ash removes the carbo¬nate hardness | |
| 96. |
In facultative stabilization pond, the sewage is treated by________________? |
| A. | aerobic bacteria only |
| B. | algae only |
| C. | dual action of aerobic bacteria and anaerobic bacteria |
| D. | sedimentation |
| Answer» D. sedimentation | |
| 97. |
In chlorination, with the rise in temperature of water, death rate of bacteria____________? |
| A. | increases |
| B. | decreases |
| C. | remains unaffected |
| D. | none of the above |
| Answer» B. decreases | |
| 98. |
In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________? |
| A. | 100 ppm |
| B. | 200 ppm |
| C. | 300 ppm |
| D. | 400 ppm |
| Answer» C. 300 ppm | |
| 99. |
If the total hardness of water is greater than its total alkalinity, the carbonate hardness will be equal to________________? |
| A. | total alkalinity |
| B. | total hardness |
| C. | total hardness – total alkalinity |
| D. | non carbonate hardness |
| Answer» B. total hardness | |
| 100. |
If the time of concentration is 9 minutes, then the intensity of rainfall according to British Ministry of Health formula will be__________________? |
| A. | 4 mm/hr |
| B. | 10mm/hr |
| C. | 20 mm/hr |
| D. | 40 mm/hr |
| Answer» E. | |