Description : The spacing of bars of perforations of fine screens used for the treatment of sewage, is A. 2 to 3 mm B. 3 to 5 mm C. 5 to 8 mm D. 8 to 10 mm
Last Answer : ANS: A
Description : The use of coarse screens for the disposal of sewage, may be dispensed with by A. Comminutor B. Shredder C. Both A. and B. D. Neither A. nor B.
Last Answer : ANS: C
Description : The design period of sewage treatment works in normally A. 5 – 10 years B. 15 – 20 years C. 30 – 40 years D. 40 – 50 years
Last Answer : ANS: B
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 : If the width of a pavement slab is 7.5 m, thickness 20 cm and working stress 1400 kg/cm2 , spacing of 10 mm tie bars for the longitudinal joint, is (A) 10 cm (B) 20 cm (C) 30 cm (D) 40 cm
Last Answer : Answer: Option C
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 : 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
Last Answer : ANS: D
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 : 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 : 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 : Aerobic activity is maximum A. In freshly produced sewage B. At sewer pipes C. In sewer treatment plants D. None of these
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 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 : Q No: 291 The coagulant widely used for sewage treatment, is A. Alum B. Ferric chloride C. Ferric sulphate D. Chlorinated copperas
Description : The sewage treatment in septic tanks is due to A. Anaerobic decomposition B. Aerobic decomposition C. Parasitic decomposition D. None of these
Description : Primary treatment of sewage consists of removal of A. Large suspended organic solids B. Oil and grease C. Sand and girt D. Floating materials
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 : Dried sewage after treatment is used as A. Fertilizer B. Building material C. Chemical for lowering B.O.D. D. Base material for paints
Description : For treating the sewage of a large city, you will recommend A. A sedimentation tank and an activated sludge treatment plant B. A plant consisting of Imhoff tanks with low rate trickling filters C. Sedimentation tanks with high rate trickling filters D. None of these
Description : The sewage treatment units in which anaerobic decomposition of organic matter is used, are called A. Imhoff tanks B. Trickling filters C. Sludge sedimentation tanks D. None of these
Description : During preliminary treatment of a sewage A. Oil and grease are removed from skimming tanks B. Floating materials are removed by screening C. Girt and sand are removed by girt chambers D. All the above
Description : The sewer that unloads the sewage at the point of treatment is called A. Main sewer B. Outfall sewer C. Branch sewer D. House sewer
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 : If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is A. 50 mg/l B. 100 mg/l C. 150 mg/l D. 250 mg/l
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 : 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 : If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, ... , the fineness modulus of the aggregate, is (A) 7.30 (B) 7.35 (C) 7.40 (D) 7.45
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 : 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
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 : The Brake Horse power of the motor (efficiency 60%) required for a pump of capacity 0.075 cumec for a total lift of 12 m, is A. 10 B. 15 C. 20 D. 25 Q No: 44 Aerobic bacterias A. ... presence of free oxygen B. Consume organic matter as their food C. Oxidise organic matter in sewage D. All the above
Description : The screens are fixed A. Perpendicular to the direction of flow B. Parallel to the direction of flow C. At an angle 30° to 60° to the direction of flow D. None of these
Description : Pick up the correct statement from the following: A. The materials separated by screens, is called screenings B. The screenings are disposed off either by burning or by burial or by dumping C. The process of burning the screenings, is known as compositing D. All the above
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 : 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
Description : Minimum clear cover (in mm) to the main steel bars in slab, beam, column and footing respectively, are (a) 10, 15, 20 and 25 (b) 15, 25, 40 and 75 (c ) 20, 25, 30 and 40 (d) 20, 35, 40 and 75
Last Answer : (b) 15, 25, 40 and 75
Description : In primary sedimentation, the 0.2 mm inorganic solids get separated if specific gravity is A. 2.25 B. 2.50 C. 2.55 D. 2.65
Description : The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours
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 : The spacing between the discs in the gang bolt ranges cm for lighy duty and cm heavy -duty harrows i. 15-25 and 25-30 c) 40-45 and 45-50 ii. 20-30 and 30-40. d) 15-25 and 32-36
Last Answer : 15-25 and 25-30
Description : Which of the following statements is incorrect? (A) Minimum cross sectional area of longitudinal reinforcement in a column is 0.8% (B) Spacing of longitudinal bars measured along the periphery of ... (D) The number of longitudinal bars provided in a circular column should not be less than four
Last Answer : Answer: Option D
Description : The main reinforcement of a R.C. slab consists of 10 mm bars at 100 mm spacing; if it is desired to replace the 10 mm bars by 12 mm bars, then the spacing of 12mm bars should be (a) 120 mm (b) 140 mm (c ) 144 mm (d) 160mm
Last Answer : (c ) 144 mm
Description : The Maximum spacing of the longitudinal bars measured long the periphery of the column should be [ A ] 250 mm [ B ] 300 mm [ C ] 400 mm [ D ] 450 mm
Last Answer : [ B ] 300 mm
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 1000 kg of sewage, the total solids approximate A. 0.5 to 1.0 kg B. 1 kg to 2.0 kg C. 5 kg to 7.5 kg D. 7.5 kg to 10 kg
Description : To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of A. Hydrochloric acid B. Sulphuric acid C. Nitric acid D. Citric acid
Description : During purification process of sewage the gas given off, is A. Carbon dioxide B. Hydrogen C. Ammonia D. All the above
Description : In sewage, the solids in mg per litre is A. 100 to 500 B. 500 to 1000 C. 1000 to 1500 D. 1500 to 2000
Description : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
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