MCQOPTIONS
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MCQOPTIONS
This section includes 641 Mcqs, each offering curated multiple-choice questions to sharpen your Civil Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
A drop manhole is provided if__________________? |
| A. | A sewer drops from a height |
| B. | A branch sewer joins the main sewer at higher level |
| C. | A lamp is inserted to check obstruction |
| D. | None of these |
| Answer» C. A lamp is inserted to check obstruction | |
| 302. |
A cylindrical ejector having its height 2 m fills after every 10 minutes with a peak sewage discharge of 0.0157 cumec. The diameter of the ejector chamber, is_____________________? |
| A. | 2.30 m |
| B. | 2.40 m |
| C. | 2.45 m |
| D. | 2.50 m |
| Answer» D. 2.50 m | |
| 303. |
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. | |
| 304. |
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» D. 25°C | |
| 305. |
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 D.O. 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 | |
| 306. |
15 cumecs, the depth d and width are related by For drains up to___________________? |
| A. | d = 0.2 B |
| B. | d = 0.5 B |
| C. | B = 0.2 d |
| D. | B = 0.5 d |
| Answer» C. B = 0.2 d | |
| 307. |
1000 kg of sewage contains________________? |
| A. | 0.112 kg in suspension |
| B. | 0.112 kg in solution |
| C. | 0.225 kg in solution |
| D. | Both A. and C. of above |
| Answer» E. | |
| 308. |
¾th or ¼th 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. | |
| 309. |
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. | |
| 310. |
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 | |
| 311. |
Assertion (A) : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable.Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities. |
| 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 | |
| 312. |
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 | |
| 313. |
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 | |
| 314. |
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. | |
| 315. |
Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is |
| A. | centrifugal pump |
| B. | pneumatic ejector |
| C. | reciprocating pump |
| D. | none of these. |
| Answer» B. pneumatic ejector | |
| 316. |
Which one of the following tests is used for testing sewer pipes : |
| A. | water test |
| B. | ball test |
| C. | mirror test |
| D. | all of these. |
| Answer» E. | |
| 317. |
If the depth of flow in a circular sewer is 1/4th of its diameter D, the wetted perimeter is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | πD. |
| Answer» D. πD. | |
| 318. |
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 | |
| 319. |
The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock's law, is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 320. |
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 | |
| 321. |
Boussinesq's equation for ascertaining unit pressure at a depth H on sewers due to traffic loads, is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| E. | none of these. |
| Answer» B. [B]. | |
| 322. |
D is the diameter of a circular sewer and α is the side of a square section sewer. If both are hydraulically equivalent, the relationship which holds good, is |
| A. | πD8/3 = 4 b8/3 |
| B. | πD3/8 = 4 b3/8 |
| C. | πD2/3 = 4 b2/3 |
| D. | πD3/2 = 4 b3/2 |
| E. | none of these. |
| Answer» B. πD3/8 = 4 b3/8 | |
| 323. |
If D is the diameter of a circular sewer and D' is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is |
| A. | D' = 0.64 D |
| B. | D' = 0.74 D |
| C. | D' = 0.84 D |
| D. | D' = 0.94 D. |
| Answer» D. D' = 0.94 D. | |
| 324. |
If D is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» B. [B]. | |
| 325. |
If the depth of partial flow in a sewer of diameter 2 m, is 50 cm, its wetted perimeter is |
| A. | π |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| E. | [E]. |
| Answer» E. [E]. | |
| 326. |
For a circular sewer of diameter D running partially full with central angle α, |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| E. | all the above. |
| Answer» F. | |
| 327. |
For having central angle α, the area of cross-section of sewers running partially full, is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 328. |
The ratio of depths at partial flow with central angle α and at full flow of a sewer, is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| E. | [E]. |
| Answer» D. [D]. | |
| 329. |
If γw is the unit weight of water, r the hydraulic mean depth of the sewer and S the bed slope of the sewer, then the tractive force exerted by flowing water, is |
| A. | γw . r . S |
| B. | γw r1/2 . S |
| C. | γw r S |
| D. | γw r2/3 S |
| Answer» B. γw r1/2 . S | |
| 330. |
In Chezy's formula V = C rs for calculating the velocity of flow in circular sewer of diameter D running full, the value of hydraulic mean radius is |
| A. | D |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| E. | [E]. |
| Answer» E. [E]. | |
| 331. |
In a city the ratio of the drainage to sewage is 20, the percentage discharge passing through non-monsoon periods, is |
| A. | 5 |
| B. | 10 |
| C. | 15 |
| D. | 20 |
| Answer» E. | |
| 332. |
The laying of sewers is done with |
| A. | agnetic compass |
| B. | heodolite |
| C. | evel |
| D. | linometer |
| Answer» D. linometer | |
| 333. |
The grit and silt of the grit chambers, may not be used for |
| A. | aising low lying areas by dumping |
| B. | oncreting |
| C. | oth A and B |
| D. | either A nor B |
| Answer» C. oth A and B | |
| 334. |
Fresh sewage may become stale in |
| A. | ne hour |
| B. | wo to three hours |
| C. | hree to four hours |
| D. | ix hours |
| Answer» D. ix hours | |
| 335. |
Bottom openings 15 cm × 15 cm in the standing baffle wall are provided |
| A. | 5 cm c/c |
| B. | 2.5 cm c/c |
| C. | 0 cm c/c |
| D. | 0 cm c/c |
| Answer» C. 0 cm c/c | |
| 336. |
The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is |
| A. | 04 cu.m |
| B. | 08 cu.m |
| C. | 12 cu.m |
| D. | 16 cu.m |
| Answer» E. | |
| 337. |
At the junction of sewers |
| A. | op of smaller sewer is kept lower |
| B. | op of larger sewer is kept lower |
| C. | ops of both the sewers are at the same level |
| D. | one of these |
| Answer» E. | |
| 338. |
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. | 5 % |
| B. | 0 % |
| C. | 0 % |
| D. | % |
| Answer» C. 0 % | |
| 339. |
Pick up the incorrect size of stone ware sewers |
| A. | 2.5 cm |
| B. | 7.5 cm |
| C. | 2.5 cm |
| D. | one of these |
| Answer» E. | |
| 340. |
Primary treatment of sewage consists of removal of |
| A. | arge suspended organic solids |
| B. | il and grease |
| C. | and and girt |
| D. | loating materials |
| Answer» B. il and grease | |
| 341. |
If is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section, is |
| A. | .250 D |
| B. | .350 D |
| C. | .425 D |
| D. | .625 D |
| Answer» E. | |
| 342. |
The small sewers are cleaned by |
| A. | lushing |
| B. | ane rodding |
| C. | ooden pills |
| D. | one of these |
| Answer» B. ane rodding | |
| 343. |
The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is |
| A. | s = 418 (Gs – Gw) d [(3T + 70)/100] |
| B. | s = 418 (Gs – Gw)d² [(3T + 70)/100] |
| C. | s = 218 (Gs – Gw)d² [(3T + 70)/100] |
| D. | s = 218 (Gs – Gw)d [(3T + 70)/100] |
| Answer» C. s = 218 (Gs – Gw)d² [(3T + 70)/100] | |
| 344. |
You are asked to design sewer pipes of diameters 0.4 m to 0.9 m at maximum flow, you will assume the sewer flow running at |
| A. | ull depth |
| B. | alf full |
| C. | wo third full |
| D. | hree fourth full |
| Answer» C. wo third full | |
| 345. |
For evaporation and measurement of settable solids, the apparatus used, is |
| A. | jar |
| B. | breaker |
| C. | test tube |
| D. | n Imhoff cone |
| Answer» E. | |
| 346. |
The settlement velocity of a solid (diameter 0.5 mm, specific gravity 1.75) in water having temperature 10°C, is |
| A. | 13.5 cm/sec |
| B. | 13.5 cm/sec |
| C. | 13.5 cm/sec |
| D. | 00 cm/sec |
| Answer» C. 13.5 cm/sec | |
| 347. |
Boussinesq’s equation for ascertaining unit pressure at a depth on sewers due to traffic loads, is |
| A. | t = 3H3p/2 Z5 |
| B. | t = 2H3p/3 Z5 |
| C. | t = 3H3p/2 Z5 |
| D. | t = 2H3p/3 Z5 |
| Answer» B. t = 2H3p/3 Z5 | |
| 348. |
depends upon The Chezy’s constant C in the formula V = C |
| A. | ize of the sewer |
| B. | hape of the sewer |
| C. | oughness of sewer surface |
| D. | ll the above |
| Answer» E. | |
| 349. |
The angle subtended by the surface of sewer water with partial flow, at sewer centre is 120°, the depth of sewerage is |
| A. | 0 cm |
| B. | 5 cm |
| C. | 0 cm |
| D. | 0 cm |
| Answer» E. | |
| 350. |
The normal values of over flow rates for sedimentation tanks using coagulant, ranges between |
| A. | 5,000 to 35,000 litres/sqm/day |
| B. | 0,000 to 50,000 litres/sqm/day |
| C. | 0,000 to 60,000 litres/sqm/day |
| D. | 0,000 to 100,000 litres/sqm/day |
| Answer» D. 0,000 to 100,000 litres/sqm/day | |