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
Last Answer : ANS: C
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
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 : 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 : 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 : Ventilating shafts are provided to a sewer line at every A. 100 m B. 150 m C. 200 m D. 300 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
Last Answer : ANS: A
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 : 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 : 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 : Antisyphonage pipe is fitted A. At the end of septic tanks B. On manholes C. With a W.C. trap D. At the beginning of sewer line
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 : Q No: 191 Design period of 40 to 50 years is adopted for A. Branch sewers B. Main sewers C. Trunk sewers D. All the above
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 : 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 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
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 : 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 : 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 sewers A. Must be of adequate size to avoid over flow B. Must flow under gravity ½ to ¾ full C. Must be laid at least 2 to 3 m deep to collect /water from the basements D. All the above
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
Last Answer : ANS: B
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 : 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 : Setting out the alignments of sewers may start from A. City B. Out-fall C. Tail end D. Any point
Description : Pick up the correct statement from the following: A. Hydrogen sulphide gas in excess, may cause corrosion of concrete sewers B. 4 ppm of Dissolved Oxygen (D.O.) is ensured before discharging the treated ... river C. Solubility of oxygen in sewage is 95% of that of distilled water D. All the above
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 : The gas which may cause explosion in sewers, is A. Carbondioxide B. Methane C. Ammonia D. Carbon monoxide
Description : Pick up the correct statement from the following: A. Small sewers are cleaned by flushing B. Medium sewers are cleaned by cane rodding C. Medium sewers may be cleaned by pills D. All the above
Description : 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
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 : No treatment of the sewage is given if dilution factor is A. Less than 150 B. Between 150 to 200 C. Between 200 to 300 D. More than 500
Description : The sewerage system originates from A. House sewers B. Lateral sewers C. Branch sewers D. Main sewers
Description : The gas evolved in sewers is A. Carbondioxide B. Hydrogen sulphide C. Methane D. All of these
Description : The small sewers are cleaned by A. Flushing B. Cane rodding C. Wooden pills D. None of these
Description : In sewers the gas generally found, is A. Hydrogen sulphide (H2S) B. Carbon dioxide (CO2) C. Methane (CH4) 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 olden days the type of section adopted in trunk and out fall sewers was A. Parabolic shaped B. Horse shoe shaped C. Egg shaped D. Circular shaped
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 : Clogging of sewers, is caused due to A. Silting B. Low discharge C. Greasy and oily matters D. All the above
Description : The laying of sewers is done with A. Magnetic compass B. Theodolite C. Level D. Clinometer
Description : Boussinesq’s equation for ascertaining unit pressure at a depth on sewers due to traffic loads, is A. pt = 3H3p/2 Z5 B. pt = 2H3p/3 Z5 C. pt = 3H3p/2Z5 D. pt = 2 3p/3Z5
Description : The most efficient cross section of sewers in a separate sewerage system is A. Parabolic B. Circular C. Rectangular D. New egged
Description : The minimum recommended diameter of sewers, is A. 5 cm B. 10 cm C. 15 cm D. 20 cm
Description : The underground sewers are more subjected to A. Tensile force B. Compressive force C. Bending force D. Shearing force
Description : The suitable cross-section of sewers to carry combined flow, is A. Circular B. Egg shaped C. Rectangular D. Horse shoe shaped
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 : 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 : 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