Description : A rainfall may be classified as acidic if its pH value is less or equal to A. 6 B. 7 C. 5 D. 6.5
Last Answer : ANS: C
Description : The amount and Intensity of monsoon rainfall is determined by the frequency of (a) western disturbances (b) dust storms (c) cyclones (d) tropical depressions
Last Answer : Ans: (d)
Description : WASTE WATER ENGINEERING Objective Questions with Answers Q No: 161 The quantity of liquid waste which flows in sewers during the period of rainfall, is known A. Sanitary sewage B. Industrial waste C. Storm sewage D. None of these
Description : The intensity of rain is expressed in A. cm/minute B. cm/hour C. cm/day D. None of these
Last Answer : ANS: B
Description : The pH value of sewage is determined with the help of A. Imhoff Cone B. Turbid meter C. Potentiometer D. None of these
Description : Which of the following statements is not true? (a) The intensity of monsoons is determined by tropical depressions (b) Tamil Nadu receives rainfall from north-east monsoon (c) Andhra Pradesh is not much affected by retreating south-west monsoon (d) All are correct
Description : The rainfall at any place is described by (A) Its intensity (B) Its duration (C) Its frequency (D) All the above
Last Answer : Answer: Option D
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 : 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 : The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these
Description : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
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 detecting the nitrites in the sewage, the matching colour may be developed by adding A. Potassium permanganate B. Sulphuric acid and napthamine C. Phenol-di -sulphuric acid potassium hydroxide D. None of these
Description : Pathogens (or pathogenic bacterias) in water may cause A. Typhoid B. Cholera C. Dysentery D. All the above
Description : For large sewers, maximum distance between manholes may be A. 50 m B. 100 m C. 200 m D. 300 m
Description : Depletion of ozone layer in the outer atmosphere may cause A. Lung cancer B. Skin cancer C. Bronchitis D. Heart disorder
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 : Setting out the alignments of sewers may start from A. City B. Out-fall C. Tail end D. Any point
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 : For detecting the nitrates in sewage, the colour may be developed by adding A. Potassium permanganate B. Sulphuric acid and napthamine C. Phenol-di -sulphuric acid and potassium hydroxide D. None of these
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.
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 : The grit and silt of the grit chambers, may not be used for A. Raising low lying areas by dumping B. Concreting C. Both A. and B. D. Neither A. nor B.
Description : Pick up the correct statement from the following: A. The maximum rate of storm runoff is called peak drainage discharge B. Rational method of estimating peak run off, may be used precisely for ... entire area starts contributing to the runoff, is called the time of concentration 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
Last Answer : ANS: A
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 : 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 larger the sewer in size, more will be velocity B. The smaller the sewer in size, less will be velocity C. The larger the sewer in size, no deposition will take place D. The larger the sewer in size, deposition will take place
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 : 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 : If the grit in grit chambers is 4.5 million litres per day, its cleaning is done A. Manually B. Mechanically C. Hydraulically D. Electrically
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
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 : 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 : 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 : The drainage area of a town is 12 hectares. Its 40% area is hard pavement ( K = 0.85), the 40% area is unpaved streets (K = 0.20) and the remaining is wooded areas (K = 0.15). Assuming the time of concentration ... 60) the maximum run off is A. 0.10 cumec B. 0.12 cumec C. 0.15 cumec D. 0.20 cumec
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 : 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 : Aerobic activity is maximum A. In freshly produced sewage B. At sewer pipes C. In sewer treatment plants 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 : hydraulically equivalent, the relationship which holds good, is A. D8/3 = 4 b8/3 B. D3/8 = 4 b3/8 C. D2/3 = 4 b2/3 D. D3/2 = 4 b3/2
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 : Sewer pipes need be checked for A. Minimum flow B. Maximum flow C. Both A. and B. 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 : In septic tanks, decomposition of organic bacteria, is done by A. Anaerobic bacteria B. Aerobic bacteria C. Both types of bacterias D. None of these
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 : The sewerage system originates from A. House sewers B. Lateral sewers C. Branch sewers D. Main sewers