Description : If the depth of flow in a circular sewer is 1/4th of its diameter D, the wetted perimeter is A. /2 B. /4 C. /3 D. D
Last Answer : ANS: C
Description : 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
Last Answer : ANS: D
Description : Hydraulic mean radius is A. Mean radius of sewer B. Difference in heads between two points in circular pipes C. Mean of radii in a pipe line of varying cross -sections D. Cross-sectional area/wetted perimeter
Description : 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
Description : 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. Full depth B. Half full C. Two third full D. Three fourth full
Last Answer : ANS: B
Description : 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
Description : The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be A. 0.9 cm B. 1.2 m C. 1.5 m D. > 1.5 m
Description : For sewer mains of 0.5 to 1 m diameter, the ratio of maximum daily sewage flow to the average daily sewage flow is assumed A. 1.5 B. 2.0 C. 2.5 D. 3.0
Description : The hydraulic mean depth or the hydraulic radius is the ratio of (A) Area of flow and wetted perimeter (B) Wetted perimeter and diameter of pipe (C) Velocity of flow and area of flow (D) None of these
Last Answer : Answer: Option A
Description : If is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section, is A. 1.250 D B. 1.350 D C. 1.425 D D. 1.625 D
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 diameter of a sewer is kept A. 10 cm B. 15 cm C. 20 cm D. 25 cm
Description : The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is A. 0.68 m B. 0.88 m C. 1.36 m D. 1.76 m
Description : Pick up the correct statement from the following: A. The boning rod is used for checking the levels of the sewer inverts B. Manhole covers are made circular for the convenience of the cleaning staff C. A manhole is classified as shallow manhole if its depth is less than 0.9 m D. All the above
Description : The gradient of sewers depends upon A. Velocity of flow B. Diameter of the sewer C. Discharge D. All the above
Description : 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. D B. D /2 C. D/3 D. D/4
Description : If the discharge of a sewer running half is 628 1.p.s., i = 0.001, and n = 0.010, the diameter of the sewer, is A. 1.39 m B. 1.49 m C. 1.59 m D. 1.69 m
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 laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of A. 100 cm B. 120 cm C. 140 cm D. 160 cm
Description : 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
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 : If is the rugosity coefficient, is the bed slope of sewer, the velocity of flow in m/sec may be obtained by the formula V = (1/n) r2/3 s1/2 evolved by A. Chezy B. Manning C. Bazin D. Kutter
Description : 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
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 : weight of water, the hydraulic mean depth of the sewer and the bed slope w is the unit of the sewer, then the tractive force exerted by flowing water, is A. w r S S B. w r1/2 C. w r S D. w r2/3
Last Answer : ANS: A
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
Description : If is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is A. D² B. D² C. D² D. D²
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 : 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
Description : If the side of a square sewer is 1000 mm, the diameter of a hydraulically equivalent circular section, is A. 1045 mm B. 1065 mm C. 1075 mm D. 1095 mm
Description : 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
Description : running partially full with central angle , For a circular sewer of diameter A. d/D = ½ (1 – – B. a/A C. r/R = [1 – D. All the above
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
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 : For design purposes, the normal rate of infiltration of ground water into the sewer, is A. 500 litres/km/cm B. 1000 litres/km/cm C. 1500 litres/km/cm D. 2000 litres/km/cm
Description : Sewer pipes need be checked for A. Minimum flow B. Maximum flow C. Both A. and B. D. None of these
Description : Dry water flow in a combined sewer, is A. Industrial sewage B. Domestic sewage C. Storm water D. Inclusive of domestic and industrial sewage but excludes storm water
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 : Pick up the correct statement from the following: A. The water supply pipes carry pure water free from solid particles B. The water supply pipes get clogged if flow velocity is less than self ... carried up and down the hills and valleys D. The sewer pipes are generally laid along level hills
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 : Ventilating shafts are provided to a sewer line at every A. 100 m B. 150 m C. 200 m D. 300 m
Description : Sewer ventilating columns are generally placed at A. Distances 150 m to 300 m B. Upper ends of branch sewers C. Every change in the size of sewers D. All the above
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 : 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. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m
Description : In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above
Description : A circular gravity aqueduct is not generally preferred to because of (A) Its maximum hydraulic mean depth (B) Maximum area per unit of wetted perimeter (C) Minimum cost of construction (D) Its proper support on the ground
Last Answer : (D) Its proper support on the ground
Description : 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
Description : 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. 1.5 B. 2.0 C. 2.5 D. 3.0
Description : The ratio of maximum sewage flow to average sewage flow for mains up to 1 m in diameter, is A. 1.5 B. 2.0 C. 3.0 D. 4.0
Description : If is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is A. D B. 1.25 D C. 1.5 D D. 1.75 D