Description : 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 ... 60) the maximum run off is A. 0.10 cumec B. 0.12 cumec C. 0.15 cumec D. 0.20 cumec
Last Answer : ANS: C
Description : 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
Last Answer : ANS: A
Description : If the diameter of sewer is 225 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
Description : 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
Last Answer : ANS: B
Description : 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
Description : 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
Last Answer : ANS: D
Description : In trickling filter, B.O.D. is reduced to A. 30 to 40% B. 40 to 60% C. 60 to 80% D. 80 to 90%
Description : 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
Description : The normal values of over flow rates for sedimentation tanks using coagulant, 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
Description : 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
Description : When drainage to sewage ratio is 20, the peak dry weather flow is A. 20% of the design discharge B. Slightly less than 5% of the design discharge C. Slightly more than 5% of the design discharge D. None of these
Description : The most effective arrangement for diverting excess storm water into a natural drainage, is A. Leaping weir B. Overflow weir C. Siphon spill way D. None of these
Description : 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
Description : The stone ware sewers A. Are used for carrying sewage and drainage from houses B. Are manufactured from clays and shale C. After casting are dried and burnt at temperature 150°C, 700°C and 1200°C D. All the above
Description : Pick up the in-correct statement from the following: A. Manholes are provided in sewer pipes at suitable intervals B. Catch basins are generally provided in sewers for carrying drainage discharge C. Inlets are generally provided in all sewers D. None of these
Description : Pick up the correct statement from the following: A. The maximum rate of storm runoff is called peak drainage discharge B. Rational method of estimating peak run off, may be used precisely for ... entire area starts contributing to the runoff, is called the time of concentration D. All the above
Description : The rational formula for peak drainage discharge, was evolved by A. Fruhling B. Lloyd David C. Kuichling D. All of these
Description : For drainage pipes in buildings the test applied before putting them to use, is A. Water test B. Smoke test C. Straightness test D. All the above
Description : Sewer manholes are generally provided at A. The change of gradient B. The change of direction C. The junctions of sewers D. All of these
Description : The gradient of sewers depends upon A. Velocity of flow B. Diameter of the sewer C. Discharge D. All the above
Description : A manhole is generally provided at each A. Bend B. Junction C. Change of gradient D. All the above
Description : In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient, A. Is only provided B. Is doubled C. Is trebled D. Is not enough
Description : 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. 100 mm dia. B. 150 mm dia. C. 225 mm dia. D. All of these
Description : 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
Description : 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 dayincubation 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
Description : 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. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l
Description : In normal conditions, the period for sludge digestion, is A. 10 days B. 20 days C. 30 days D. 60 days
Description : For the survival of fish in a river stream, the minimum dissolved oxygen is prescribed A. 3 ppm B. 4 ppm C. 5 ppm D. 10 ppm
Description : The minimum diameter of sewer to be adopted is A. 10 cm B. 12.5 cm C. 15 cm D. 25 cm
Description : The minimum recommended diameter of sewers, is A. 5 cm B. 10 cm C. 15 cm D. 20 cm
Description : The minimum diameter of a sewer is kept A. 10 cm B. 15 cm C. 20 cm D. 25 cm
Description : If the peak discharge of a storm water drain (S.W. Drain) is expected to exceed 150 cumecs, the free board to be provided, is A. 100 cm B. 90 cm C. 80 cm D. 50 cm
Description : If the viscosity of ground water is 1.00, the Slitcher's constant is 400, the effective size of soil particles in aquifer is 0.5 mm and hydraulic gradient is 1 in 80, the velocity of flow is (A) 0.25 m/day (B) 0.50 m/day (C) 1.00 m/day (D) 1.25 m/day
Last Answer : Answer: Option D
Description : Drop manholes at the junctions of sewer lines, are provided if A. Invert level of a branch sewer is more than 60 cm that of the main sewer B. Sewer line runs along a main road C. Ordinary manhole cannot be built D. Two sewer lines intersect
Description : A nuisance is experienced in diluting water if dilution factor is less than A. 100 B. 60 C. 40 D. 20
Description : Pick up the correct statement from the following: A. Inlets are provided on the road surface at the lowest point for draining rain water B. Inlets are generally provided at an interval of ... along straight roads C. Inlets having horizontal openings, are called horizontal inlets D. All the above
Description : To maintain aerobic biological activity, the moisture content of the compost mass should be about A. 45 % B. 50 % C. 55 % D. 60 %
Description : To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is A. 0.50 m/sec B. 0.60 m/sec C. 0.70 m/sec D. 0.75 m/sec
Description : 11. 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
Description : Sewer pipes need be checked for A. Minimum flow B. Maximum flow C. Both A. and B. D. None of these
Description : The ratio of minimum hourly flow to the average flow of sewage is A. 1/4 B. 1/3 C. 1/2 D. 3/4
Description : 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 ... correct explanation of A C. A is true but R is false D. A is false but R is true
Description : A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is A. 0.30 m/sec B. 0.35 m/sec C. 0.40 m/sec D. 0.45 m/sec
Description : Which one of the following part of human body withstands minimum radiation? A. Thyroid B. Kidneys C. Eyes D. Ovaries/testis
Description : 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 ... . The minimum width of septic level is 90 cm D. The depth of tank is kept equal to its width
Description : Pick up the correct statement from the following: A. Maximum daily flow = 2 times the average daily flow B. Maximum daily flow = average daily flow C. Sewers are designed for minimum permissible velocity at minimum flow D. All the above
Description : Pick up the correct statement from the following: A. The sewer pipes of sizes less than 0.4 m diameter are designed as running full at maximum discharge B. The sewer pipes of sizes greater than 0.4 m ... discharge C. The minimum design velocity of sewer pipes is taken as 0.8 m/sec D. All the above
Description : For efficient working of a sewer, it must be ensured that A. Minimum velocity of 0.45 m/sec, is maintained at its minimum flow B. A maximum velocity of 0.90 m/sec, is maintained at its maximum flow C. Both A. and B. D. Neither A. nor B.
Description : The sewer which transports the sewage to the point of treatment, is called A. House sewer B. Out-fall sewer C. Branch sewer D. Main sewer
Description : The sewerage system originates from A. House sewers B. Lateral sewers C. Branch sewers D. Main sewers