MCQOPTIONS
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MCQOPTIONS
This section includes 89 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The minimum depth of septic tank as per design consideration is |
| A. | a) 1.8m |
| B. | b) 1m |
| C. | c) 1.2m |
| D. | d) 1.5m |
| Answer» D. d) 1.5m | |
| 2. |
Which of the following is not the method of disposal of sewage from septic tank? |
| A. | upflow anaerobic filter |
| B. | soil absorption system |
| C. | vacuum filter |
| D. | biological filters |
| Answer» D. biological filters | |
| 3. |
What is the maximum design flow of sewage in a septic tank? |
| A. | 70 liters per person per day |
| B. | 100 liters per person per day |
| C. | 30 liters per person per day |
| D. | 40 liters per person per day |
| Answer» B. 100 liters per person per day | |
| 4. |
The concentration of biodegradable organic matter after the septic tank is |
| A. | 50ppm |
| B. | 100ppm |
| C. | 200ppm |
| D. | 75ppm |
| Answer» D. 75ppm | |
| 5. |
The detention period of a septic tank is |
| A. | 2 hours |
| B. | 12-36 hours |
| C. | 4 hours |
| D. | 1 week |
| Answer» C. 4 hours | |
| 6. |
The disposal of sewage from the septic tank is done by which of the following? |
| A. | clarifier |
| B. | soak pit |
| C. | aerated lagoon |
| D. | lamp holes |
| Answer» C. aerated lagoon | |
| 7. |
Which of the following process is not adopted in oxidation ditches? |
| A. | adsorption |
| B. | desorption |
| C. | oxidation |
| D. | decomposition |
| Answer» C. oxidation | |
| 8. |
What is the range of MLSS concentration in oxidation ditch? |
| A. | 500-1000 mg/l |
| B. | 1000-2000 mg/l |
| C. | 2000-4000 mg/l |
| D. | 3000-5000 mg/l |
| Answer» E. | |
| 9. |
The ditch is lined by                layer. |
| A. | brick |
| B. | cement |
| C. | permeable |
| D. | impermeable |
| Answer» E. | |
| 10. |
What is the shape of the oxidation ditch? |
| A. | square |
| B. | rectangular |
| C. | circular |
| D. | oval |
| Answer» E. | |
| 11. |
What is the minimum depth of water to be kept in the oxidation pond? |
| A. | 0.3m |
| B. | 0.5m |
| C. | 1 m |
| D. | 1.5m |
| Answer» D. 1.5m | |
| 12. |
The maximum BOD removal efficiency of an oxidation pond is |
| A. | 0.9 |
| B. | 0.68 |
| C. | 0.7 |
| D. | 0.8 |
| Answer» B. 0.68 | |
| 13. |
The detention period of oxidation pond is |
| A. | 12-36 hours |
| B. | 4 hours |
| C. | 10-20 days |
| D. | 30-60 seconds |
| Answer» D. 30-60 seconds | |
| 14. |
The minimum design depth of oxidation pond is |
| A. | 0.3m |
| B. | 0.5m |
| C. | 1m |
| D. | 1.5m |
| Answer» D. 1.5m | |
| 15. |
Which of the following is an anaerobic process for treating sewage? |
| A. | oxidation pond |
| B. | imhoff tank |
| C. | oxidation ditch |
| D. | rotating biological contactors |
| Answer» C. oxidation ditch | |
| 16. |
In which stage of the SBR is aeration performed? |
| A. | first |
| B. | second |
| C. | third |
| D. | fourth |
| Answer» C. third | |
| 17. |
How is mixing done in SBR? |
| A. | manual |
| B. | mechanical |
| C. | air stripping |
| D. | agitation by air |
| Answer» C. air stripping | |
| 18. |
SBR is a type of |
| A. | aerobic process |
| B. | activated sludge process |
| C. | anaerobic process |
| D. | chemical process |
| Answer» C. anaerobic process | |
| 19. |
Which reactors are characterized by non- continuous reactions? |
| A. | plug flow reactor |
| B. | continuous reactor |
| C. | batch reactor |
| D. | fluidized bed reactor |
| Answer» D. fluidized bed reactor | |
| 20. |
Which type of reactor is used for mixing chemicals in water treatment? |
| A. | continuous reactor |
| B. | batch reactor |
| C. | plug flow reactor |
| D. | fixed bed reactor |
| Answer» C. plug flow reactor | |
| 21. |
The maximum depth of aeration tank used in activated sludge process is |
| A. | 1m |
| B. | 2m |
| C. | 4.5m |
| D. | 5.5m |
| Answer» D. 5.5m | |
| 22. |
Which of the following is called as air diffusion method? |
| A. | activated sludge aeration |
| B. | diffused air aeration |
| C. | mechanical aeration |
| D. | combined aeration |
| Answer» C. mechanical aeration | |
| 23. |
The size of filter media in a high rate trickling filter is |
| A. | 10-20mm |
| B. | 34-68mm |
| C. | 25-60mm |
| D. | 20-50mm |
| Answer» D. 20-50mm | |
| 24. |
               is the ratio of volume of recirculated sewage to the raw sewage. |
| A. | recirculation factor |
| B. | recirculation ratio |
| C. | food to mass ratio |
| D. | bod |
| Answer» C. food to mass ratio | |
| 25. |
The color of the secondary sludge produced from the high rate trickling filter is |
| A. | gray |
| B. | black |
| C. | brown |
| D. | green |
| Answer» D. green | |
| 26. |
The organic loading in low rate trickling filter is 900 kg/hectare- meter/day. What is the efficiency of the filter? |
| A. | 0.431 |
| B. | 0.883 |
| C. | 0.0704 |
| D. | 0.83 |
| Answer» C. 0.0704 | |
| 27. |
The BOD after the filtration of sewage from the low rate trickling filter is |
| A. | 40-50% |
| B. | 80-90% |
| C. | 70-80% |
| D. | 90-99% |
| Answer» C. 70-80% | |
| 28. |
The maximum size of filter media of a percolating filter is |
| A. | 10mm |
| B. | b) 25mm |
| C. | c) 60mm |
| D. | d) 75mm |
| Answer» E. | |
| 29. |
Which of the following filter is used in the anaerobic treatment of sewage? |
| A. | intermittent sand |
| B. | trickling filter |
| C. | contact filter |
| D. | biological filter |
| Answer» E. | |
| 30. |
The depth of the filter media of intermittent filter is |
| A. | 45cm |
| B. | 60cm |
| C. | 20cm |
| D. | 25cm |
| Answer» C. 20cm | |
| 31. |
How many types of trickling filters are used in sewage treatment? |
| A. | a) |
| B. | 5 |
| C. | 3 |
| D. | 2 |
| Answer» E. | |
| 32. |
The detention period of detritus tank is |
| A. | 40 seconds |
| B. | 1 minute |
| C. | 3 minute |
| D. | 1 hour |
| Answer» D. 1 hour | |
| 33. |
How many types of aerators are commonly used in the treatment of wastewater? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» B. 3 | |
| 34. |
In preliminary treatment of sewage, the operation which takes place, is |
| A. | removal of fine suspended particles |
| B. | removal of fine dissolved organic material |
| C. | removal of lighter floating material |
| D. | removal of harmful bacterias and other organisms |
| Answer» D. removal of harmful bacterias and other organisms | |
| 35. |
The average time required by water to pass through the settling tank is called |
| A. | detention time |
| B. | flow through period |
| C. | time of flow |
| D. | mean time |
| Answer» C. time of flow | |
| 36. |
What is the settling velocity of the particle in the wastewater if its diameter is 2 * 10-3cm. Given G=2.65, viscosity v=8 * 10-3cm2/Sec? |
| A. | 0.01cm/sec |
| B. | 0.13cm/sec |
| C. | 0.24cm/sec |
| D. | 0.36cm/sec |
| Answer» C. 0.24cm/sec | |
| 37. |
In which settling type, dilute suspension of particles takes place? |
| A. | zone settling |
| B. | compression settling |
| C. | hindered settling |
| D. | discrete settling |
| Answer» D. discrete settling | |
| 38. |
In which type of settling, settling of particles takes place by the contact of impurities with each other present in wastewater? |
| A. | flocculent settling |
| B. | hindered settling |
| C. | compression settling |
| D. | discrete settling |
| Answer» D. discrete settling | |
| 39. |
The settling velocity of spherical particle is given by |
| A. | darcy weisbach equation |
| B. | hazen and william equation |
| C. | stokes equation |
| D. | bernoulli’s equation |
| Answer» D. bernoulli’s equation | |
| 40. |
In which type of settling, sedimentation of discrete particles takes place? |
| A. | zone settling |
| B. | compression settling |
| C. | hindered settling |
| D. | discrete settling |
| Answer» E. | |
| 41. |
How many types of settling are there in the sedimentation tank? |
| A. | 3 |
| B. | 4 |
| C. | 5 |
| D. | 6 |
| Answer» C. 5 | |
| 42. |
Which of the following device is used for the removal of oil and grease? |
| A. | skimming tank |
| B. | grit chambers |
| C. | tube settlers |
| D. | flocculator |
| Answer» B. grit chambers | |
| 43. |
The design velocity of flow of a detritus tank is |
| A. | 1m/sec |
| B. | 1.2m/sec |
| C. | 0.9m/sec |
| D. | 0.5m/sec |
| Answer» D. 0.5m/sec | |
| 44. |
What is the maximum capacity of medium screen in collecting solids? |
| A. | 30l |
| B. | 40l |
| C. | 50l |
| D. | 90l |
| Answer» E. | |
| 45. |
The maximum spacing between the bars in medium screen is |
| A. | 40mm |
| B. | 50mm |
| C. | 70mm |
| D. | 90mm |
| Answer» B. 50mm | |
| 46. |
Screens are inclined to the direction of flow to |
| A. | increase the flow velocity |
| B. | increase the opening area |
| C. | decrease the flow velocity |
| D. | increase the head loss |
| Answer» D. increase the head loss | |
| 47. |
The spacing between the bars in racks is |
| A. | 30mm |
| B. | 50mm |
| C. | 70mm |
| D. | 90mm |
| Answer» C. 70mm | |
| 48. |
The minimum spacing between the bars on fine screen is |
| A. | 0.3mm |
| B. | 0.9mm |
| C. | 1.5mm |
| D. | 0.5mm |
| Answer» D. 0.5mm | |
| 49. |
The reoxygenation constant at temperature ‘T’ is expressed by |
| A. | krt = kr20 (1.016)t |
| B. | krt = kr20 (1.047) t-20 |
| C. | krt = kr20 (1.016)t-20 |
| D. | krt = kr20 (1.047)t |
| Answer» D. krt = kr20 (1.047)t | |
| 50. |
Which of the following represents the oxygen sag curve in the following figure? |
| A. | dotted blue line |
| B. | green curve |
| C. | yellow curve |
| D. | red curve |
| Answer» E. | |