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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.
351. |
Kjeldahl nitrogen is a mixture of |
A. | mmonia and nitrogen |
B. | itrogen and organic nitrogen |
C. | rganic nitrogen and ammonia |
D. | ll the above |
Answer» E. | |
352. |
¾th or ¼th extra space is left in sewer pipes at maximum discharge for |
A. | ow estimates of the average and maximum flows |
B. | arge scale infiltration of storm water |
C. | nexpected increase in population |
D. | ll the above |
Answer» E. | |
353. |
The formula which accepts the value of rugosity coefficient n = 0.012 to be used in Manning’s formula, is given by |
A. | azin |
B. | rimp and Bruges |
C. | illiam-Hazen |
D. | utter |
Answer» C. illiam-Hazen | |
354. |
In sewers the velocity of flow should not be |
A. | ore than the self-cleansing velocity |
B. | ess than the self-cleansing velocity |
C. | ess than 10 m/sec |
D. | ore than 20 m/sec |
Answer» C. ess than 10 m/sec | |
355. |
Cement concrete sewers are only suitable if non-scouring velocity is between |
A. | .5 to 3.0 m/sec |
B. | .0 to 4.0 m/sec |
C. | .5 to 4.5 m/sec |
D. | .5 to 5.5 m/sec |
Answer» B. .0 to 4.0 m/sec | |
356. |
Sludge banks are formed if sewage is disposed of in |
A. | ivers |
B. | eas |
C. | akes |
D. | one of these |
Answer» C. akes | |
357. |
A five 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. | 00 |
B. | 000 |
C. | 000 |
D. | 0000 |
Answer» E. | |
358. |
A drop manhole is provided if |
A. | sewer drops from a height |
B. | branch sewer joins the main sewer at higher level |
C. | lamp is inserted to check obstruction |
D. | one of these |
Answer» C. lamp is inserted to check obstruction | |
359. |
The formula V = (1/n) r2/3 |
A. | hezy’s formula |
B. | azin’s formula |
C. | utter’s formula |
D. | anning’s formula |
Answer» E. | |
360. |
‘Cowl’ is provided at |
A. | ower end of ventilating column |
B. | pper end of ventilating column |
C. | pper end of the manhole |
D. | irst step in manhole |
Answer» C. pper end of the manhole | |
361. |
Which one of the following part of human body withstands minimum radiation? |
A. | hyroid |
B. | idneys |
C. | yes |
D. | varies/testis |
Answer» E. | |
362. |
If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity is |
A. | in 60 |
B. | in 100 |
C. | in 120 |
D. | one of these |
Answer» B. in 100 | |
363. |
Pathogens (or pathogenic bacterias) in water may cause |
A. | yphoid |
B. | holera |
C. | ysentery |
D. | ll the above |
Answer» E. | |
364. |
To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of |
A. | ydrochloric acid |
B. | ulphuric acid |
C. | itric acid |
D. | itric acid |
Answer» C. itric acid | |
365. |
For the COD test of sewage, organic matter is oxidised by K₂Cr₂O₇ in the presence of |
A. | ₂SO₄ |
B. | NO₃ |
C. | Cl |
D. | one of these |
Answer» B. NO₃ | |
366. |
Hazen’s formula VS = 418 (GS – Gw)d [(3T + 70)/100] is used for the settlement velocity of the particles of diameter |
A. | ess than 0.01 mm |
B. | ess than 0.05 mm |
C. | ess than 0.1 mm |
D. | reater than 0.1 mm |
Answer» E. | |
367. |
In Chezy’s formula V = C rs for calculating the velocity of flow in circular sewer of diameter running full, the value of hydraulic mean radius is |
A. | /1 |
B. | /2 |
C. | /3 |
D. | /4 |
Answer» E. | |
368. |
If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains |
A. | ydrogen sulphide |
B. | arbon dioxide |
C. | ethane |
D. | xygen |
Answer» C. ethane | |
369. |
For trunk sewers more than 1.25 m in diameter, the ratio of the maximum daily sewage flow to the average daily sewage flow is assumed |
A. | 0.5 |
B. | 0 |
C. | 0.5 |
D. | 0 |
Answer» B. 0 | |
370. |
In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time? |
A. | 00 mm dia |
B. | 50 mm dia |
C. | 25 mm dia |
D. | ll of these |
Answer» D. ll of these | |
371. |
The rational formula for peak drainage discharge, was evolved by |
A. | ruhling |
B. | loyd David |
C. | uichling |
D. | ll of these |
Answer» E. | |
372. |
In normal conditions, the period for sludge digestion, is |
A. | 0 days |
B. | 0 days |
C. | 0 days |
D. | 0 days |
Answer» D. 0 days | |
373. |
If is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is |
A. | .15 D |
B. | .25 D |
C. | .5 D |
D. | .75 D |
Answer» D. .75 D | |
374. |
The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is |
A. | ² (0.011d + 0.785H)/Q |
B. | (0.022d + 0.085H)/Q |
C. | (0.785d + 0.011H)/Q |
D. | (0.285d + 0.011H)/Q |
Answer» B. (0.022d + 0.085H)/Q | |
375. |
During purification process of sewage the gas given off, is |
A. | arbon dioxide |
B. | ydrogen |
C. | mmonia |
D. | ll the above |
Answer» E. | |
376. |
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. | 00 mg/l |
B. | 00 mg/l |
C. | 00 mg/l |
D. | 00 mg/l |
Answer» D. 00 mg/l | |
377. |
The minimum diameter of a sewer is kept |
A. | 0 cm |
B. | 5 cm |
C. | 0 cm |
D. | 5 cm |
Answer» C. 0 cm | |
378. |
The most efficient cross-section of sewers in a combined sewerage system is |
A. | arabolic |
B. | ircular |
C. | ectangular |
D. | ew egged |
Answer» C. ectangular | |
379. |
Facultative bacteria survive in |
A. | he presence of oxygen |
B. | he absence of oxygen |
C. | oth cases A and B |
D. | either A nor B |
Answer» D. either A nor B | |
380. |
Dry weather flow is: |
A. | verage daily rate of flow |
B. | verage monthly rate of flow |
C. | verage annual rate of flow |
D. | ater supply allowance per capita |
Answer» E. | |
381. |
Are available in size Stoneware sewers |
A. | 0 cm |
B. | 5 cm |
C. | 0 cm |
D. | ll the above |
Answer» E. | |
382. |
The minimum diameter of sewer to be adopted is |
A. | 0 cm |
B. | 2.5 cm |
C. | 5 cm |
D. | 5 cm |
Answer» D. 5 cm | |
383. |
If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is |
A. | 0 mg/l |
B. | 00 mg/l |
C. | 50 mg/l |
D. | 50 mg/l |
Answer» E. | |
384. |
If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is |
A. | 00 ppm |
B. | 25 ppm |
C. | 50 ppm |
D. | one of these |
Answer» D. one of these | |
385. |
If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is |
A. | 00 mg/l |
B. | 00 mg/l |
C. | 00 mg/l |
D. | 00 mg/l |
Answer» E. | |
386. |
Acid regression stage of sludge digestion at a temperature 21°C extends over a period of |
A. | 5 days |
B. | 0 days |
C. | 0 days |
D. | 0 days |
Answer» E. | |
387. |
If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is |
A. | 0 ppm |
B. | 00 ppm |
C. | 50 ppm |
D. | 00 ppm |
Answer» E. | |
388. |
The discharge per unit plan area of a sedimentation tank, is generally called |
A. | ver flow rate |
B. | urface loading |
C. | ver flow velocity |
D. | ll the above |
Answer» E. | |
389. |
Which one of the following statements regarding septic tanks is wrong? |
A. | gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided |
B. | he outlet invert level is kept 5 to 7.5 cm below the inlet invert level |
C. | he minimum width of septic level is 90 cm |
D. | he depth of tank is kept equal to its width |
Answer» E. | |
390. |
The sewage treatment in septic tanks is due to |
A. | naerobic decomposition |
B. | erobic decomposition |
C. | arasitic decomposition |
D. | one of these |
Answer» B. erobic decomposition | |
391. |
Nitrogen cycle of sewage, is |
A. | iberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen |
B. | iberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates |
C. | iberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia |
D. | ormation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates |
Answer» B. iberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates | |
392. |
hydraulically equivalent, the relationship which holds good, is |
A. | 8/3 = 4 b8/3 |
B. | 3/8 = 4 b3/8 |
C. | 2/3 = 4 b2/3 |
D. | 3/2 = 4 b3/2 |
Answer» B. 3/8 = 4 b3/8 | |
393. |
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. | ’ = 0.64 D |
B. | ’ = 0.74 D |
C. | ’ = 0.84 D |
D. | ’ = 0.94 D |
Answer» D. ’ = 0.94 D | |
394. |
The quantity of liquid waste which flows in sewers during the period of rainfall, is known |
A. | anitary sewage |
B. | ndustrial waste |
C. | torm sewage |
D. | one of these |
Answer» D. one of these | |
395. |
The value of Chezy’s constant C = 157.6/(1.81 + K/ ) is used in |
A. | hezy’s formula |
B. | azin’s formula |
C. | utter’s formula |
D. | anning’s formula |
Answer» C. utter’s formula | |
396. |
Drop manholes are the manholes |
A. | ithout entry ladders |
B. | ithout manhole covers |
C. | ith depths more than 3.5 m |
D. | aving drains at different levels |
Answer» E. | |
397. |
The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope |
A. | in 5 |
B. | in 10 |
C. | in 15 |
D. | in 20 |
Answer» C. in 15 | |
398. |
The drop man holes are generally provided in sewers for |
A. | 3 hours. |
B. | industrial areas |
C. | large town ships |
D. | hilly town ships |
Answer» D. hilly town ships | |
399. |
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. | none of these. |
B. | 100 cm |
C. | 110 cm |
D. | 120 cm |
Answer» D. 120 cm | |
400. |
The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is |
A. | neither (a) nor (b). |
B. | 1.5 |
C. | 2 |
D. | 3 |
Answer» B. 1.5 | |