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 : 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
Last Answer : ANS: A
Description : A drop manhole is provided if A. A sewer drops from a height B. A branch sewer joins the main sewer at higher level C. A lamp is inserted to check obstruction D. None of these
Last Answer : ANS: B
Description : ‘Cowl’ is provided at A. Lower end of ventilating column B. Upper end of ventilating column C. Upper end of the manhole D. First step in manhole
Description : The inspection pit or chamber is a manhole provided in a base drainage system (A) At every change of direction (B) At every change of gradient (C) At every 30 m intervals (D) All the above
Last Answer : (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 : If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains A. Hydrogen sulphide B. Carbon dioxide C. Methane D. Oxygen
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 : 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
Last Answer : ANS: C
Description : A safety lamp when inserted in the upper portion of a manhole causes flames. It indicates the presence of A. Carbondioxide gas B. Hydrogen sulphide gas C. Methane gas D. Petrol vapours
Description : Lead acetate test in sewer manhole is done to test the presence of A. Methane gas B. Hydrogen sulphide C. Carbondioxide gas D. Diesel vapours
Description : Drop manholes are the manholes A. Without entry ladders B. Without manhole covers C. With depths more than 3.5 m D. Having drains at different levels
Description : 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
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 : 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
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. 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 : Pick up the incorrect statement from the following: A. Septic tanks are horizontal continuous flow type of sedimentation tanks B. Septic tanks are generally provided a detention period of 12 to 36 hours C ... covered and high vent shafts are provided for the escape of foul gases D. None of these
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 : 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 : The gradient of sewers depends upon A. Velocity of flow B. Diameter of the sewer C. Discharge D. All the above
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 : For house drainage minimum gradient is A. 1 in 60 B. 1 in 80 C. 1 in 10 D. 1 in 400
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 : 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 : 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 : 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 : A sewer is laid from a manhole to a manhole , 250 m away along a gradient of 1 in 125. If the reduced level of the invert at is 205.75 m and the height of the boning rod is 3 m, the reduced level of the sight rail at , is (A) 208.75 m (B) 202.75 m (C) 206.75 m (D) 211.75 m
Last Answer : (C) 206.75 m
Description : Ventilating shafts are provided to a sewer line at every A. 100 m B. 150 m C. 200 m D. 300 m
Description : For sewers, inverted siphon is provided for A. One pipe B. Two pipes C. Three pipes D. Four pipes
Description : Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank. A. Both A and R is true and R is the correct ... is not a correct explanation of A C. A is true but R is false D. A is false but R is true
Description : 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
Description : In septic tanks, A. Free board of 0.3 m may be provided B. The baffles or tees are extended up to top level of scum C. The clear space between the baffle top and covering slab is about 7.5 cm D. All the above
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 : Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers
Description : Pick up the correct statement from the following: A. The circular section of sewers provides maximum hydraulic mean depth B. The circular sewers are provided for separate sewerage system C. The circular sewers work efficiently if the sections run at least half full D. All the above
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 : Bottom openings 15 cm × 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
Description : Before discharging the foul sewage into rivers, it is generally treated by A. Screening B. Sedimentation C. Oxidation D. All the above
Description : In sewers the gas generally found, is A. Hydrogen sulphide (H2S) B. Carbon dioxide (CO2) C. Methane (CH4) D. All the above
Description : Rate of flow of sewage is generally assumed A. More than the rate of water supply B. Equal to the rate of water supply C. Less than the rate of water supply D. At 150 litres per capita
Description : House connections to the laterals is generally made by A. R.C.C. B. P.C.C. C. Cast iron D. Glazed stonewares
Description : Fresh sewage is generally A. Alkaline B. Acidic C. Highly decomposed D. A source of objectionable odour
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 : For trunk and out-fall, the type of sewers generally used, is A. Standard egg shaped B. Circular shaped C. Horse shoe shaped D. Parabolic shaped
Description : The asbestos cement pipes are generally laid A. Horizontally B. Vertically C. At an angle of 30° D. At an angle of 60°
Description : An inverted siphon is designed generally for A. One pipe B. Two pipes C. Three pipes D. Four pipes
Description : The grit chambers of sewage treatment plants, are generally cleaned after A. 2 days B. 7 days C. 12 days D. 14 days
Description : Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these