Description : For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is A. 16 m B. 20 m C. 24 m D. 30 m
Last Answer : ANS: C
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 : 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 : 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
Last Answer : ANS: A
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 : 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 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.
Last Answer : ANS: B
Description : In case of Imhoff tanks, A. The shape is rectangular B. Detention period is 2 hours C. The velocity of flow is restricted to 0.30 m/minute D. All the above
Description : The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m
Description : In detritus tanks, A. Flow velocity is kept 0.09 m/sec B. Detention period is kept 3 to 4 minutes C. Organic and inorganic materials are separated D. All the above
Description : The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m
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 : The detention period for plain sedimentation water tanks, is usually A. 4 to 8 hours B. 8 to 16 hours C. 16 to 24 hours D. 24 to 36 hours
Description : The detention period in a septic tank is assumed (A) 20 minutes (B) 25 minutes (C) 30 minutes (D) 40 minute
Last Answer : (C) 30 minutes
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 : The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q
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 : Indicate which of the statement is incorrect (a) The detritus tank is type of a grit chamber (b) In detritus tank, velocity of flow is further reduced (c) Grit chambers are provided in the sewage ... to remove the heavier inorganic matter as grit, sand etc. from the sewage (d) None of them*
Last Answer : (d) None of them*
Description : Pick up the correct statement from the following: (A) Detention period for plain sedimentation tanks ranges between 4 to 8 hours (B) Detention period for sedimentation tanks, using coagulants usually ... in sedimentation tanks, is generally limited to 0.3 m/minute (D) All the above
Last Answer : (D) All the above
Description : For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above
Description : The minimum recommended diameter of sewers, is A. 5 cm B. 10 cm C. 15 cm D. 20 cm
Description : The intensity of rain is expressed in A. cm/minute B. cm/hour C. cm/day D. None of these
Description : The rate of accumulation of sludge in septic tanks is recommended as A. 30 litres/person/year B. 25 litres/person/year C. 30 litres/person/month D. 25 litres/person/month
Description : In areas where rainy season is limited to a few months, the type of sewerage system recommended is A. Combined system B. Partially separate system C. Separate system D. None of these
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 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 : 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 : 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 : 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 : 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 digested sludge from septic tanks, is removed after a maximum period of A. 3 years B. 3.5 years C. 4 years D. 5 years
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
Description : The design period in years for pumping plants, is A. 1 B. 2 to 3 C. 3 to 5 D. 5 to 10
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 : 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 : In normal conditions, the period for sludge digestion, is A. 10 days B. 20 days C. 30 days D. 60 days
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 : 11. Acid regression stage of sludge digestion at a temperature 21°C extends over a period of A. 15 days B. 30 days C. 60 days D. 90 days
Description : An intense rain is falling at a uniform rate of 7.5 cm/hour for a period of 60 minutes on a basin whose area is 500 hectares. If the average infiltration capacity during the entire rain period is assumed to be 1.5 ... of the basin, is (A) 40 cumecs (B) 60 cumecs (C) 80 cumecs (D) 100 cumecs
Last Answer : Answer: Option C
Description : In order to be effective, Percutaneous Transluminal Coronary Angioplasty (PTCA) must be performed within what time frame, beginning with arrival at the emergency department after diagnosis of myocardial ... during which streptokinase will not be used again in the same patient for acute MI.
Last Answer : a) 60 minutes The sixty minute interval is known as “door to balloon time” for performance of PTCA on a diagnosed MI patient.
Description : In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks. (A) 1 to 2 (B) 4 to 5 (C) 9 to 10 (D) 15 to 20
Last Answer : (B) 4 to 5
Description : The Constitution allows preventive detention but stipulates: (1) that no one should be detained beyond three months unless an Advisory Board authorizes detention beyond that period (2) that the grounds for ... nearest magistrate within a period of 24 hours of his arrest (4) All of the above
Last Answer : (1) that no one should be detained beyond three months unless an Advisory Board authorises detention beyond that period Explanation: Article 22 (4) provides that no law providing for preventive detention ... said period of 3 months that there is in it's opinion sufficient cause for such detention.
Description : In a sedimentation tank, the detention period for water ranges from __________ hours. (A) 2 to 4 (B) 8 to 12 (C) 16 to 20 (D) 24 to 32
Last Answer : (A) 2 to 4
Description : The efficiency of sedimentation tank does not depend upon (A) Depth of tank (B) Length of tank (C) Detention period (D) Velocity of water
Last Answer : (D) Velocity of water
Description : Detention period of a settling tank is (A) Average theoretical time required for water to flow through the tank (B) Time required for flow of water to fill the tank fully (C) Average time for which water is retained in tank (D) All the above
Description : Flow through period, in sedimentation tanks, is (A) Equal to detention period (B) More than detention period (C) Less than detention period (D) Detention period divided by displacement efficiency
Last Answer : (C) Less than detention period
Description : The detention period for plain sedimentation water tanks, is usually (A) 4 to 8 hours (B) 8 to 16 hours (C) 16 to 24 hours (D) 24 to 36 hours
Last Answer : (D) 24 to 36 hours
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 : The standard B.O.D. of water is taken for A. 1 day B. 2 days C. 3 days D. 5 days
Description : In R.C. sewer pipes, the percentage longitudinal reinforcement to the cross-sectional area of concrete is kept A. 10.0 B. 5.0 C. 2.0 D. 0.25