MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 5814 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 4251. |
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» E. | |
| 4252. |
In sewers the velocity of flow should not be |
| A. | more than the self-cleansing velocity |
| B. | less than the self-cleansing velocity |
| C. | less than 10 m/sec |
| D. | more than 20 m/sec. |
| Answer» C. less than 10 m/sec | |
| 4253. |
3.0 ml of raw sewage is diluted to 300 ml. The D.O. concentration of the diluted sample at the beginning of the test was 8 mg/l. After 5 day-incubation at 20 C, the DO. concentration was 5 mg/l. The BOD of raw sewerage is |
| A. | 100 mg/l |
| B. | 200 mg/l |
| C. | 300 mg/l |
| D. | 400 mg/l. |
| Answer» D. 400 mg/l. | |
| 4254. |
If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains |
| A. | Hydrogen sulphide |
| B. | Carbon dioxide |
| C. | Methane |
| D. | Oxygen |
| E. | None of these. |
| Answer» B. Carbon dioxide | |
| 4255. |
The design period of sewage treatment works in normally |
| A. | 5 - 10 years |
| B. | 15 - 20 years |
| C. | 30 - 40 years |
| D. | 40 - 50 years. |
| Answer» C. 30 - 40 years | |
| 4256. |
The porosity of sediments in sewer pipes, is usually taken as |
| A. | 0.010 |
| B. | 0.011 |
| C. | 0.012 |
| D. | 0.013 |
| E. | 0.020 |
| Answer» E. 0.020 | |
| 4257. |
If the grit in grit chambers is 4.5 million litres per day, its cleaning is done |
| A. | manually |
| B. | mechanically |
| C. | hydraulically |
| D. | electrically. |
| Answer» B. mechanically | |
| 4258. |
The gas evolved in sewers is |
| A. | Carbondioxide |
| B. | Hydrogen sulphide |
| C. | Methane |
| D. | All of these. |
| Answer» E. | |
| 4259. |
The maximum depth of sedimentation tanks, is kept |
| A. | 3 m |
| B. | 3.5 m |
| C. | 4 m |
| D. | 4.5 m. |
| Answer» B. 3.5 m | |
| 4260. |
The reduced levels of the string at the consecutive sight rails A and B are 203.575 m, 203.475 m respectively. If the difference of their R.D.s is 10 m, the gradient of the sewer line is |
| A. | 1 in 100 upward |
| B. | 1 in 500 upward |
| C. | 1 in 100 downward |
| D. | 1 in 503 upward. |
| Answer» D. 1 in 503 upward. | |
| 4261. |
The detention time (t) of a settling tank, may be defined as the time required for |
| A. | a particle to travel along its length |
| B. | a particle to travel from top surface to bottom sludge zone |
| C. | the flow of sewage to fill the tank |
| D. | none of these. |
| Answer» D. none of these. | |
| 4262. |
A circular sewer section is preferred to because |
| A. | it is cheaper in construction |
| B. | it provides maximum area for a given perimeter |
| C. | it provides maximum hydraulic mean depth |
| D. | all the above. |
| Answer» E. | |
| 4263. |
Assertion (A) : The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R) : If certain deposition takes place and is not removed, it obstructs free flow and causes further deposition leading to complete blocking of the sewer. |
| 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 | |
| 4264. |
Assertion (A) : A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R) : It helps to accommodate the scum in the septic tank. |
| 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 | |
| 4265. |
In sewage, the solids in mg per litre is |
| A. | 100 to 500 |
| B. | 500 to 1000 |
| C. | 1000 to 1500 |
| D. | 1500 to 2000 |
| Answer» C. 1000 to 1500 | |
| 4266. |
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» D. 85%. | |
| 4267. |
If D is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is |
| A. | <img src="/_files/images/civil-engineering/waste-water-engineering/183-9.58-1.png"> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/183-9.58-2.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/183-9.58-3.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/183-9.58-4.png"> |
| Answer» B. <img src="/_files/images/civil-engineering/waste-water-engineering/183-9.58-2.png"> | |
| 4268. |
The angle subtended by the surface of sewer water with partial flow, at sewer centre is 120 , the depth of sewerage is |
| A. | 20 cm |
| B. | 25 cm |
| C. | 40 cm |
| D. | 50 cm |
| E. | 60 cm. |
| Answer» E. 60 cm. | |
| 4269. |
Imhoff cone is used to determine |
| A. | settlable solids |
| B. | suspended solids |
| C. | dissolved solids |
| D. | none of these. |
| Answer» B. suspended solids | |
| 4270. |
The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is |
| A. | 100 cm |
| B. | 110 cm |
| C. | 120 cm |
| D. | 150 cm. |
| Answer» D. 150 cm. | |
| 4271. |
For a peak discharge of 0.0157 cumec, with a velocity of 0.9 m/sec, the diameter of the sewer main, is |
| A. | 10 cm |
| B. | 12 cm |
| C. | 15 cm |
| D. | 18 cm |
| E. | 20 cm. |
| Answer» D. 18 cm | |
| 4272. |
In case of sewer lines |
| A. | water test is carried out to check water tightness of the joints |
| B. | test for straightness is carried out with the help of a lamp and mirror |
| C. | obstruction test is carried out with the. help of smooth ball of diameter 13 mm |
| D. | all the above. |
| Answer» E. | |
| 4273. |
The sewerage system originates from |
| A. | house sewers |
| B. | lateral sewers |
| C. | branch sewers |
| D. | main sewers |
| E. | out fall sewers. |
| Answer» B. lateral sewers | |
| 4274. |
'Cowl' is provided at |
| A. | lower end of ventilating column |
| B. | upper end of ventilating column |
| C. | upper end of the manhole |
| D. | first step in manhole. |
| Answer» C. upper end of the manhole | |
| 4275. |
The sewer which transports the sewage to the point of treatment, is called |
| A. | house sewer |
| B. | out-fall sewer |
| C. | branch sewer |
| D. | lateral |
| E. | main sewer. |
| Answer» C. branch sewer | |
| 4276. |
Kjedahl nitrogen is a mixture of |
| A. | ammonia and nitrogen |
| B. | nitrogen and organic nitrogen |
| C. | organic nitrogen and ammonia |
| D. | all the above. |
| Answer» E. | |
| 4277. |
Discrete or granular particles change their |
| A. | size |
| B. | shape |
| C. | weight |
| D. | none of these. |
| Answer» E. | |
| 4278. |
Increase in population of a rapidly growing city, may be estimated by |
| A. | arithmetical mean method |
| B. | geometrical method |
| C. | incremental increase method |
| D. | graphical comparison method. |
| Answer» C. incremental increase method | |
| 4279. |
Flow through period, in sedimentation tanks, is |
| A. | equal to detention period |
| B. | more than detention period |
| C. | less than detention period |
| D. | detention period divided by displacement efficiency |
| E. | none of these. |
| Answer» D. detention period divided by displacement efficiency | |
| 4280. |
The cast iron pipes for water supply system are used for |
| A. | durability |
| B. | strength |
| C. | easy connection |
| D. | low maintenance cost |
| E. | all the above. |
| Answer» F. | |
| 4281. |
A nuisance is experienced in diluting water if dilution factor is less than |
| A. | 100 |
| B. | 60 |
| C. | 40 |
| D. | 20 |
| E. | 10 |
| Answer» E. 10 | |
| 4282. |
Traps |
| A. | are water seals which prevent the entry of foul gases |
| B. | are used to trap the rats entering sewers |
| C. | dissolve the foul gases |
| D. | create syphonic action to increase the quick disposal of sewerage. |
| Answer» B. are used to trap the rats entering sewers | |
| 4283. |
For estimating the peak run off the rational formula Q = 0.0278 KpA was evolved by |
| A. | Kinchling |
| B. | Lloyd Davis |
| C. | Frubling |
| D. | all the above. |
| Answer» E. | |
| 4284. |
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» C. partially combined system | |
| 4285. |
Sewer pipes need be checked for |
| A. | minimum flow |
| B. | maximum flow |
| C. | both (a) and (b) |
| D. | none of these. |
| Answer» D. none of these. | |
| 4286. |
If D.O. concentration falls down to zero in any natural drainage, it indicates the zone of |
| A. | degradation |
| B. | active decomposition |
| C. | recovery |
| D. | cleaner water |
| E. | none of these. |
| Answer» C. recovery | |
| 4287. |
The ratio of design discharge to the surface area of a sedimentation tank is called |
| A. | surface loading |
| B. | overflow rate |
| C. | overflow velocity |
| D. | all of these. |
| Answer» E. | |
| 4288. |
The value of Chezy's constant is used in |
| A. | Chezy's formula |
| B. | Bazin's formula |
| C. | Kutter's |
| D. | Manning's formula. |
| Answer» D. Manning's formula. | |
| 4289. |
The pH value of fresh sewage is usually |
| A. | equal to 7 |
| B. | more than 7 |
| C. | less than 7 |
| D. | equal to zero. |
| Answer» C. less than 7 | |
| 4290. |
The moisture content of a sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is |
| A. | 25% |
| B. | 50% |
| C. | 10% |
| D. | 5%. |
| Answer» C. 10% | |
| 4291. |
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» E. | |
| 4292. |
To maintain aerobic biological activity, the moisture content of the compost mass should be about |
| A. | 45% |
| B. | 50% |
| C. | 55% |
| D. | 60%. |
| Answer» D. 60%. | |
| 4293. |
The sewer that unloads the sewage at the point of treatment is called |
| A. | main sewer |
| B. | outfall sewer |
| C. | branch sewer |
| D. | house sewer. |
| Answer» C. branch sewer | |
| 4294. |
No treatment of the sewage is given if dilution factor is |
| A. | less than 150 |
| B. | between 150 to 200 |
| C. | between 200 to 300 |
| D. | between 400 to 500 |
| E. | more than 500 |
| Answer» F. | |
| 4295. |
R.M.O. expenses include |
| A. | running expenses |
| B. | maintenance expenses |
| C. | operation expenses |
| D. | all the above. |
| Answer» E. | |
| 4296. |
A pressure conduit carrying water beneath a stream or a canal, is known as |
| A. | sag |
| B. | depressed pipe |
| C. | inverted syphon |
| D. | all the above. |
| Answer» E. | |
| 4297. |
Suction lift of a pump depends upon |
| A. | atmospheric pressure |
| B. | water temperature |
| C. | velocity of water in suction pipe |
| D. | frictional losses |
| E. | all the above. |
| Answer» F. | |
| 4298. |
The pH value of sewage is determined with the help of |
| A. | Imhoff Cone |
| B. | turbidimeter |
| C. | potentiometer |
| D. | none of these. |
| Answer» D. none of these. | |
| 4299. |
Perched acquifers generally occur |
| A. | below water table |
| B. | above water table |
| C. | in acquicludes |
| D. | in artesian acquifers |
| E. | none of these. |
| Answer» C. in acquicludes | |
| 4300. |
The maximum spacing of manholes specified by Indian standard in sewers upto 0.3 m diameter is |
| A. | 20 m |
| B. | 30 m |
| C. | 45 m |
| D. | 75 m. |
| Answer» D. 75 m. | |