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
Last Answer : ANS: A
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
Last Answer : ANS: D
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
Last Answer : ANS: C
Description : The sewer which received discharge from two or more main sewers, is known as A. A trunk sewer B. An outfall sewer C. A main sewer D. An intercepting sewer
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 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 : 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 : 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 : Self cleaning velocity of a sewer line depends upon (a) Diameter of sewer (b) Gradient of ewer line (c) Type of sewerage (d) All of them*
Last Answer : d) All of them*
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 : 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 : 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 : The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is A. 0.05552 cumec B. 0.05554 cumec C. 0.05556 cumec D. 0.0556 cumec
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 : At the junction of sewers A. Top of smaller sewer is kept lower B. Top of larger sewer is kept lower C. Tops of both the sewers are at the same level D. None of these
Description : Pick up the incorrect statement from the following for allowing workers to enter sewers A. The particular manhole and one manhole on upstream and one manhole on downstream should remain open for 30 ... entering the manhole should be advised to smoke in the sewer D. Warning signals should be erected
Description : depends upon The Chezy’s constant C in the formula V = C A. Size of the sewer B. Shape of the sewer C. Roughness of sewer surface D. All the above
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 : In sewers the velocity of flow should not be A. More than the self-cleansing velocity B. Less than the self-cleansing velocity C. Less than 10 m/sec D. More than 20 m/sec
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 : 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 : If the depth of partial flow in a sewer of diameter 2 m, is 50 cm, its wetted perimeter is A. B. /2 C. /3 D. 2 /3
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 : 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
Description : Clogging of sewers, is caused due to A. Silting B. Low discharge C. Greasy and oily matters D. All the above
Description : For design of sewers, percentage of sewage discharge is assumed A. 65 to 70% B. 70 to 75% C. 75 to 80% D. 85%
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 : 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 : 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 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 : 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 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
Description : 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
Description : 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
Description : The sewer pipes A. Carry sewage as gravity conduits B. Are designed for generating self-cleansing velocities at different discharge C. Should resist the wear and tear caused due to abrasion D. All the above
Description : Large diameter sewers subjected to external pressure alone, are reinforced A. Near the inner surface of the pipe B. Near the outer surface of the pipe C. Both A. and B. D. With elliptical cage
Description : The minimum recommended diameter of sewers, is A. 5 cm B. 10 cm C. 15 cm D. 20 cm
Description : The maximum spacing of manholes specified by Indian standard in sewers upto 0.3 m diameter is A. 20 m B. 30 m C. 45 m D. 75 m
Description : The maximum diameter of sewers adopted in the designs is A. 1.0 m B. 2.0 m C. 3.0 m D. 4.0 m
Description : With self cleansing velocity in sewers A. Silting occurs at bottom B. Scouring occurs at bottom C. Both silting and scouring occur at bottom D. Neither silting nor scouring occurs at bottom
Description : 221 For non-scouring velocity 5 m/sec, the type of sewers generally preferred to, is A. Cast iron sewers B. Cement concrete sewers C. Glazed bricks sewers D. Stone ware sewers
Description : In sewers the highest non-scouring velocity is achieved in A. Glazed bricks sewers B. Cast iron sewers C. Cement concrete sewers D. Stone ware sewers
Description : In sewers designed with self cleansing velocity, A. The bottom is silted B. The bottom is scoured C. Both silting and scouring occur at the bottom D. Neither silting nor scouring occurs at the bottom
Description : 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
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 : The discharge per unit plan area of a sedimentation tank, is generally called A. Over flow rate B. Surface loading C. Over flow velocity D. All the above
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 : The minimum diameter of sewer to be adopted is A. 10 cm B. 12.5 cm C. 15 cm D. 25 cm
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