MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The design period in years for pumping plants, is |
| A. | 1 |
| B. | 2 to 3 |
| C. | 3 to 5 |
| D. | 5 to 10 |
| Answer» E. | |
| 2. |
The settlement velocity of a solid (diameter 0.5 mm, specific gravity 1.75) in water having temperature 10 C, is |
| A. | 213.5 cm/sec |
| B. | 313.5 cm/sec |
| C. | 413.5 cm/sec |
| D. | 500 cm/sec. |
| Answer» C. 413.5 cm/sec | |
| 3. |
The Chezy's constant C in the formula V = C rs depends upon |
| A. | size of the sewer |
| B. | shape of the sewer |
| C. | roughness of sewer surface |
| D. | hydraulic characteristics of sewer |
| E. | all the above. |
| Answer» F. | |
| 4. |
Afive day B.O.D. at 15 C of the sewage of a town is 100 kg/day. If the 5 day B.O.D. per head at 15 C for standard sewage is 0.1 kg/day, the population equivalent is |
| A. | 100 |
| B. | 1000 |
| C. | 5000 |
| D. | 10000 |
| Answer» E. | |
| 5. |
Silt storage is the same as |
| A. | dead storage |
| B. | live storage |
| C. | effective storage |
| D. | none of these. |
| Answer» B. live storage | |
| 6. |
The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is |
| A. | 0.05552 cumec |
| B. | 0.05554 cumec |
| C. | 0.05556 cumec |
| D. | 0.0556 cumec |
| E. | 0.0558 cumec. |
| Answer» D. 0.0556 cumec | |
| 7. |
For complete stabilisation of organic matter in polluted water, it takes |
| A. | 5 days |
| B. | 10 days |
| C. | 20 days |
| D. | 30 days |
| E. | 40 days. |
| Answer» E. 40 days. | |
| 8. |
The maximum diameter of sewers adopted in the designs is |
| A. | 1.0 m |
| B. | 2.0 m |
| C. | 3.0 m |
| D. | 4.0 m. |
| Answer» D. 4.0 m. | |
| 9. |
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» E. | |
| 10. |
Sluge banks are formed if sewage is disposed of in |
| A. | rivers |
| B. | seas |
| C. | lakes |
| D. | none of these. |
| Answer» C. lakes | |
| 11. |
Design period of 40 to 50 years is adopted for |
| A. | branch sewers |
| B. | main sewers |
| C. | trunk sewers |
| D. | all the above. |
| Answer» E. | |
| 12. |
The water carried sewerage system removes |
| A. | domestic sewage |
| B. | industrial sewage |
| C. | storm sewage |
| D. | all the above. |
| Answer» E. | |
| 13. |
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» B. less than 7 | |
| 14. |
Ventilating shafts are provided to a sewer line at every |
| A. | 100 m |
| B. | 150 m |
| C. | 200 m |
| D. | 300 m |
| E. | 500 m. |
| Answer» E. 500 m. | |
| 15. |
If the peak discharge of a storm water drain (S.W. Drain) is e.xpected to exceed 150 cumecs, the free board to be provided, is |
| A. | 100 cm |
| B. | 90 cm |
| C. | 80 cm |
| D. | 50 cm. |
| Answer» B. 90 cm | |
| 16. |
Depletion of ozone layer in the outer atmosphere may cause |
| A. | lung cancer |
| B. | skin cancer |
| C. | bronchitis |
| D. | heart disorder. |
| Answer» C. bronchitis | |
| 17. |
The spacing of bars of perforations of fine screens used for the treatment of sewage, is |
| A. | 2 to 3 mm |
| B. | 3 to 5 mm |
| C. | 5 to 8 mm |
| D. | 8 to 10 mm. |
| Answer» B. 3 to 5 mm | |
| 18. |
If n is the rugosity coefficient, r is the hydraulic depth, s is the bed slope of sewer, the velocity of flow in m/sec may be obtained by the formula evolved by |
| A. | Chezy |
| B. | Manning |
| C. | Bazin |
| D. | Kutter. |
| Answer» C. Bazin | |
| 19. |
rd or th extra space is left in sewer pipes at maximum discharge for |
| A. | low estimates of the average and maximum flows |
| B. | large scale infiltration of storm water |
| C. | unexpected increase in population |
| D. | all the above. |
| Answer» E. | |
| 20. |
Antisyphonage pipe is fitted |
| A. | at the end of septic tanks |
| B. | on manholes |
| C. | with a W.C. trap |
| D. | at the beginning of sewer line. |
| Answer» D. at the beginning of sewer line. | |
| 21. |
As compared to fresh river water, sea water contains oxygen |
| A. | 10% less |
| B. | 20% less |
| C. | 10% more |
| D. | 20% more. |
| Answer» C. 10% more | |
| 22. |
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» E. | |
| 23. |
Skimming tanks are |
| A. | used to remove the grease and oil |
| B. | those from which sludge is skimmed out |
| C. | tanks provided with self-cleansing screens |
| D. | improved version of grit chambers. |
| Answer» B. those from which sludge is skimmed out | |
| 24. |
In sewers designed with self cleansing velocity, |
| A. | the bottom is silted |
| B. | the bottom is scoured |
| C. | both silting and scouring occur at the bottom |
| D. | neither silting nor scouring occurs at the bottom. |
| Answer» E. | |
| 25. |
In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is |
| A. | <img src="/_files/images/civil-engineering/waste-water-engineering/192-9.188-1.png"> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/192-9.188-2.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/192-9.188-3.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/192-9.188-4.png"> |
| Answer» D. <img src="/_files/images/civil-engineering/waste-water-engineering/192-9.188-4.png"> | |
| 26. |
Stoneware sewers are available in size |
| A. | 10 cm |
| B. | 15 cm |
| C. | 20 cm |
| D. | 25 cm |
| E. | all the above. |
| Answer» F. | |
| 27. |
The sludge does not contain waste water from |
| A. | bath rooms |
| B. | wash basins |
| C. | kitchen sinks |
| D. | toilets. |
| Answer» E. | |
| 28. |
Boussinesq's equation for ascertaining unit pressure at a depth H on sewers due to traffic loads, is |
| A. | <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-1.png"> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-2.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-3.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-4.png"> |
| E. | none of these. |
| Answer» B. <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-2.png"> | |
| 29. |
Aerobic activity is maximum |
| A. | in freshly produced sewage |
| B. | at sewer pipes |
| C. | in sewer treatment plants |
| D. | none of these. |
| Answer» B. at sewer pipes | |
| 30. |
Stone ware pipes are |
| A. | highly resistant to sulphide corrosion |
| B. | highly impervious |
| C. | hydraulically efficient because of their smooth interior surface |
| D. | specially suited to pressure pipes |
| E. | none of these. |
| Answer» E. none of these. | |
| 31. |
For detecting the nitrites in the sewage, the matching colour may be developed by adding |
| A. | Pottassium permanganate |
| B. | Sulphuric acid and napthamine |
| C. | Phenol-di-sulphuric acid pottassium hydroxide |
| D. | None of these. |
| Answer» C. Phenol-di-sulphuric acid pottassium hydroxide | |
| 32. |
The suitable cross-section of sewers to carry combined flow, is |
| A. | circular |
| B. | egg shaped |
| C. | rectangular |
| D. | horse shoe shaped. |
| Answer» C. rectangular | |
| 33. |
Hazin's formula is used for the settlement velocity of the particles of diameter |
| A. | less than 0.01 mm |
| B. | less than 0.05 mm |
| C. | less than 0.1 mm |
| D. | greater than 0.1 mm. |
| Answer» E. | |
| 34. |
The minimum diameter of a sewer is kept |
| A. | 10 cm |
| B. | 15 cm |
| C. | 20 cm |
| D. | 25 cm |
| E. | 30 cm. |
| Answer» C. 20 cm | |
| 35. |
The minimum diameter of sewer to be adopted is |
| A. | 10 cm |
| B. | 12.5 cm |
| C. | 15 cm |
| D. | 25 cm. |
| Answer» D. 25 cm. | |
| 36. |
The intensity of rain is expressed in |
| A. | cm/minute |
| B. | cm/hour |
| C. | cm/day |
| D. | none of these. |
| Answer» C. cm/day | |
| 37. |
1000 kg of sewage contains |
| A. | 0.112 kg in suspension |
| B. | 0.112 kg in solution |
| C. | 0.225 kg in solution |
| D. | 0.450 kg in suspension |
| E. | both (a) and (c) of above. |
| Answer» F. | |
| 38. |
The rational formula for peak drainage discharge, was evolved by |
| A. | Fruhling |
| B. | Lloyd David |
| C. | Kuichling |
| D. | All of these. |
| Answer» E. | |
| 39. |
The sewage treatment in septic tanks is due to |
| A. | anaerobic decomposition |
| B. | aerobic decomposition |
| C. | parasitic decomposition |
| D. | none of these. |
| Answer» B. aerobic decomposition | |
| 40. |
Which one of the following resists hydrogen sulphide corrosion |
| A. | R.C.C. |
| B. | Glazed stone wares |
| C. | Asbestos cement |
| D. | Glazed ware. |
| Answer» E. | |
| 41. |
Hume steel pipes are |
| A. | steel pipes |
| B. | R.C.C. pipes |
| C. | steel shell coated from inside with cement mortar |
| D. | steel shell coated from outside with cement mortar |
| E. | both (c) and (d). |
| Answer» F. | |
| 42. |
Assertion (A) : The determination of pH value of sewerage is important. Reason (R) : The efficiency of certain treatment methods depends upon the availability of pH value. |
| A. | Both A and R are true and R is the correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true. |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 43. |
With self cleansing velocity in sewers |
| A. | silting occurs at bottom |
| B. | scouring occurs at bottom |
| C. | both silting and scouring occur at bottom |
| D. | neither silting nor scouring occurs at bottom. |
| Answer» E. | |
| 44. |
If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity, is |
| A. | 1 in 60 |
| B. | 1 in 100 |
| C. | 1 in 120 |
| D. | none of these. |
| Answer» B. 1 in 100 | |
| 45. |
To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by pottassium dichromate in the presence of |
| A. | Hydrochloric acid |
| B. | Sulphuric acid |
| C. | Nitric acid |
| D. | Citric acid. |
| Answer» C. Nitric acid | |
| 46. |
The grit and silt of the grit chambers, may not be used for |
| A. | raising low lying areas by dumping |
| B. | concreting |
| C. | both (a) and (b) |
| D. | neither (a) nor (b). |
| Answer» C. both (a) and (b) | |
| 47. |
In a sludge tank, the gas mainly produced, is |
| A. | Oxygen |
| B. | Nitrogen |
| C. | Hydrogen |
| D. | Carbon dioxide |
| E. | Methane. |
| Answer» F. | |
| 48. |
Pick up the incorrect statement from the following for allowing workers to enter sewers |
| A. | The particular manhole and one manhole on up stream and one manhole on down stream should remain open for 30 minutes |
| B. | Proper tests for the presence of poisonous gases must be carried out |
| C. | The men entering the manhole should be advised to smoke in the sewer |
| D. | Warning signals should be erected |
| E. | None of these. |
| Answer» D. Warning signals should be erected | |
| 49. |
The discharge per unit plan area of a sedimentation tank, is generally called |
| A. | over flow rate |
| B. | surface loading |
| C. | over flow velocity |
| D. | all the above. |
| Answer» E. | |
| 50. |
In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is |
| A. | <img src="/_files/images/civil-engineering/waste-water-engineering/190-9.166-1.png"> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/190-9.166-2.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/190-9.166-3.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/190-9.166-4.png"> |
| Answer» E. | |