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.
| 4601. |
The detention period for plain sedimentation water tanks, is usually |
| A. | 4 to 8 hours |
| B. | 8 to 16 hours |
| C. | 16 to 24 hours |
| D. | 24 to 36 hours. |
| Answer» B. 8 to 16 hours | |
| 4602. |
The effluent of a septic tank is |
| A. | fit for discharge into any open drain |
| B. | foul and contains dissolved and suspended solids |
| C. | as good as that from a complete treatment |
| D. | none of these. |
| Answer» B. foul and contains dissolved and suspended solids | |
| 4603. |
The drainage area of a town is 12 hectares. Its 40% area is hard pavement (K = 0.85), the 40% area is unpaved streets (K = 0.20) and the remaining is wooded areas (K = 0.15). Assuming the time of concentration for the areas as 30 minutes and using the formula the maximum run off is |
| A. | 0.10 cumec |
| B. | 0.12 cumec |
| C. | 0.15 cumec |
| D. | 0.20 cumec. |
| Answer» D. 0.20 cumec. | |
| 4604. |
A sewer running partially full and hurried with back filled, fails in compression due to |
| A. | weight of the pipe |
| B. | weight of the back fill |
| C. | superimposed traffic loads |
| D. | all the above. |
| Answer» E. | |
| 4605. |
A manhole is classified as shallow if its depth is between |
| A. | 0.4 to 0.5 m |
| B. | 0.5 to 0.7 m |
| C. | 0.7 to 0.9 m |
| D. | 0.9 to 1.20 m |
| E. | 1.2 to 1.50 m. |
| Answer» D. 0.9 to 1.20 m | |
| 4606. |
The standard B.O.D. of water is taken for |
| A. | 1 day |
| B. | 2 days |
| C. | 3 days |
| D. | 5 days |
| E. | 10 days. |
| Answer» E. 10 days. | |
| 4607. |
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. | |
| 4608. |
The digested sludge from septic tanks, is removed after a maximum period of |
| A. | 3 years |
| B. | 3.5 years |
| C. | 4 years |
| D. | 5 years. |
| Answer» B. 3.5 years | |
| 4609. |
The gradient of sewers depends upon |
| A. | velocity of flow |
| B. | diameter of the sewer |
| C. | discharge |
| D. | all the above. |
| Answer» E. | |
| 4610. |
The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is |
| A. | 30 minutes |
| B. | 1 hour |
| C. | 1 hour and 30 minutes |
| D. | 2 hours |
| E. | 3 hours. |
| Answer» E. 3 hours. | |
| 4611. |
For providing an Indian type W.C., the R.C.C. slabs in the toilet portion |
| A. | should be sunk by 20 cm |
| B. | should be kept 20 cm above the adjacent portion |
| C. | should be sunk by 50 cm |
| D. | need not be sunk. |
| Answer» D. need not be sunk. | |
| 4612. |
The underground sewers are more subjected to |
| A. | tensile force |
| B. | compressive force |
| C. | bending force |
| D. | shearing force. |
| Answer» C. bending force | |
| 4613. |
The grit chambers of sewage treatment plants, are generally cleaned after |
| A. | 2 days |
| B. | 5 days |
| C. | 7 days |
| D. | 12 days |
| E. | 14 days. |
| Answer» F. | |
| 4614. |
Cement concrete sewers are only suitable if non-scouring velocity is between |
| A. | 2.5 to 3.0 m/sec |
| B. | 3.0 to 4.0 m/sec |
| C. | 3.5 to 4.5 m/sec |
| D. | 4.5 to 5.5 m/sec. |
| Answer» B. 3.0 to 4.0 m/sec | |
| 4615. |
The drop man holes are generally provided in sewers for |
| A. | industrial areas |
| B. | large town ships |
| C. | hilly town ships |
| D. | cities in plains. |
| Answer» D. cities in plains. | |
| 4616. |
The normal values of over flow rates for secondary sedimentation tanks, ranges between |
| A. | 25, 000 to 35, 000 litres/sqm/day |
| B. | 40, 000 to 50, 000 litres/sqm/day |
| C. | 50, 000 to 60, 000 litres/sqm/day |
| D. | 80, 000 to 10, 000 litres/sqm/day |
| E. | none of these. |
| Answer» B. 40, 000 to 50, 000 litres/sqm/day | |
| 4617. |
The spacing of bars for perforations in coarse screens used for the treatment of sewage, is |
| A. | 20 mm |
| B. | 30 mm |
| C. | 40 mm |
| D. | 50 mm |
| E. | 100 mm. |
| Answer» E. 100 mm. | |
| 4618. |
Acid regression stage of sludge digestion at a temperature 21 C extends over a period of |
| A. | 15 days |
| B. | 30 days |
| C. | 60 days |
| D. | 90 days. |
| Answer» E. | |
| 4619. |
If the pH value of sewage is 7 |
| A. | it is acidic |
| B. | it is alkaline |
| C. | it is neutral |
| D. | none of these. |
| Answer» D. none of these. | |
| 4620. |
The Brake Horse power of the motor (efficiency 60%) required for a pump of capacity 0.075 cumec for a total lift of 12 m, is |
| A. | 10 |
| B. | 15 |
| C. | 20 |
| D. | 25 |
| Answer» D. 25 | |
| 4621. |
If the flame of a miner's safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains |
| A. | Hydrogen sulphide |
| B. | Carbon dioxide |
| C. | Methane |
| D. | Oxygen |
| E. | None of these. |
| Answer» D. Oxygen | |
| 4622. |
Setting out the alignments of sewers may start from |
| A. | city |
| B. | out-fall |
| C. | tail end |
| D. | any point. |
| Answer» D. any point. | |
| 4623. |
If the flame of a miner's safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains |
| A. | Hydrogen sulphide |
| B. | Carbon dioxide |
| C. | Methane |
| D. | Oxygen |
| E. | None of these. |
| Answer» C. Methane | |
| 4624. |
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. | <i>D</i> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/181-9.29-1.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/181-9.29-2.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/181-9.29-3.png"> |
| E. | <img src="/_files/images/civil-engineering/waste-water-engineering/181-9.29-4.png"> |
| Answer» E. <img src="/_files/images/civil-engineering/waste-water-engineering/181-9.29-4.png"> | |
| 4625. |
The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known |
| A. | house sewer |
| B. | lateral sewer |
| C. | branch sewer |
| D. | sewer outfall. |
| Answer» E. | |
| 4626. |
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. | 50 ppm |
| B. | 100 ppm |
| C. | 150 ppm |
| D. | 200 ppm |
| E. | 250 ppm. |
| Answer» E. 250 ppm. | |
| 4627. |
In very first stage of decomposition of the organic matter in sewage |
| A. | nitrites are formed |
| B. | nitrates are formed |
| C. | carbondioxide is formed |
| D. | ammonia is formed. |
| Answer» E. | |
| 4628. |
The normal value of over flow rates for plain primary sedimentation tanks, ranges between |
| A. | 25, 000 to 35, 000 litres/sqm/day |
| B. | 40, 000 to 50, 000 litres/sqm/day |
| C. | 50, 000 to 60, 000 litres/sqm/day |
| D. | 80, 000 to 100, 000 litres/sqm/day |
| E. | none of these. |
| Answer» C. 50, 000 to 60, 000 litres/sqm/day | |
| 4629. |
The asbestos cement sewers are |
| A. | light in weight |
| B. | not structurally strong to bear large compressive stress |
| C. | susceptible to corrosion by sulphuric acid |
| D. | All the above. |
| Answer» E. | |
| 4630. |
Bottom openings 15 cm x 15 cm in the standing baffle wall are provided |
| A. | 15 cm c/c |
| B. | 22.5 cm c/c |
| C. | 30 cm c/c |
| D. | 50 cm c/c. |
| Answer» C. 30 cm c/c | |
| 4631. |
For having central angle , the area of cross-section of sewers running partially full, is |
| A. | <img src="/_files/images/civil-engineering/waste-water-engineering/182-9.50-1.png"> |
| B. | <img src="/_files/images/civil-engineering/waste-water-engineering/182-9.50-2.png"> |
| C. | <img src="/_files/images/civil-engineering/waste-water-engineering/182-9.50-3.png"> |
| D. | <img src="/_files/images/civil-engineering/waste-water-engineering/182-9.50-4.png"> |
| Answer» C. <img src="/_files/images/civil-engineering/waste-water-engineering/182-9.50-3.png"> | |
| 4632. |
The pressure exerted by |
| A. | the sewage when running full from inside, is called internal pressure |
| B. | the internal pressure if any, causes tensile stress in the pipe material |
| C. | pressure sewers are designed to be safe in tension |
| D. | All the above. |
| Answer» E. | |
| 4633. |
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. | |
| 4634. |
For the open drain (N = 0.025) shown in the below figure, the discharge is |
| A. | 26.88 cumecs |
| B. | 27.88 cumecs |
| C. | 28.88 cumecs |
| D. | 29.88 cumecs. |
| Answer» D. 29.88 cumecs. | |
| 4635. |
If the diameter of a sewer is 150 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» C. 1 in 120 | |
| 4636. |
The average temperature of sewage in India, is |
| A. | 10 C |
| B. | 15 C |
| C. | 20 C |
| D. | 25 C |
| E. | 30 C. |
| Answer» D. 25 C | |
| 4637. |
In normal conditions, the period for sludge digestion, is |
| A. | 10 days |
| B. | 20 days |
| C. | 30 days |
| D. | 60 days |
| E. | 90 days. |
| Answer» D. 60 days | |
| 4638. |
The most widely used pump for lifting sewage is |
| A. | centrifugal pump |
| B. | reciprocating pump |
| C. | pneumatic ejector |
| D. | air pressure pump. |
| Answer» B. reciprocating pump | |
| 4639. |
For a continuous flow type of sedimentation tanks |
| A. | width of the tank is normally kept about 6 m |
| B. | length of the tank is normally kept 4 to 5 times the width |
| C. | maximum horizontal flow velocity is limited to 0.3 m/minute |
| D. | capacity of the tank for 24 hours, is kept equal to maximum daily flow of sewage |
| E. | all the above. |
| Answer» F. | |
| 4640. |
Faculative bacterias survive in |
| A. | the presence of oxygen |
| B. | the absence of oxygen |
| C. | both cases (a) and (b) |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 4641. |
The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope |
| A. | 1 in 5 |
| B. | 1 in 10 |
| C. | 1 in 15 |
| D. | 1 in 20 |
| E. | 1 in 25 |
| Answer» C. 1 in 15 | |
| 4642. |
The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is |
| A. | 1.5 |
| B. | 2.0 |
| C. | 3.0 |
| D. | 4.0 |
| Answer» B. 2.0 | |
| 4643. |
The sewer which resists sulphide corrosion, is |
| A. | Brick sewer |
| B. | Cast iron sewer |
| C. | R.C.C. sewer |
| D. | Lead sewer |
| E. | None of these. |
| Answer» E. None of these. | |
| 4644. |
The flow velocity in detritus tanks is |
| A. | 0.05 m/sec |
| B. | 0.09 m/sec |
| C. | 1.25 m/sec |
| D. | none of these. |
| Answer» C. 1.25 m/sec | |
| 4645. |
The following is the physical characteristic of sewage |
| A. | turbidity |
| B. | colour |
| C. | odour |
| D. | temperature |
| E. | all the above. |
| Answer» F. | |
| 4646. |
The temperature affects the |
| A. | biological activity of bacterias in sewage |
| B. | solubility of gases in sewage |
| C. | viscosity of sewage |
| D. | all the above. |
| Answer» E. | |
| 4647. |
Sewer pipes are designed for maximum discharge with 25% to 33% vacant cross-sectional area for |
| A. | unexpected large scale infiltration of stream water |
| B. | unexpected increase in the population |
| C. | under estimates of maximum and average flows |
| D. | All of the above. |
| Answer» E. | |
| 4648. |
For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is |
| A. | 16 m |
| B. | 20 m |
| C. | 24 m |
| D. | 30 m. |
| Answer» D. 30 m. | |
| 4649. |
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 | |
| 4650. |
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. | |