Description : Pick up the correct statement from the following: A. In treated sewage, 4 ppm of D.O. is essential B. Only very fresh sewage contains some dissolved oxygen C. The solubility of oxygen in sewage is 95% that is in distilled water D. All the above
Last Answer : ANS: D
Description : Dilution method of disposing of sewage, is not preferred to A. When sewage is fresh B. When diluting water has high dissolved oxygen content C. When diluting water is used for water supply near the point of sewage disposed D. When the diluting water is having flow currents
Last Answer : ANS: C
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
Last Answer : ANS: B
Description : WASTE WATER Engineering Objective Questions Pdf :: Q No: 151 The pH value of fresh sewage is usually A. Equal to 7 B. More than 7 C. Less than 7 D. Equal to zero
Description : The factor responsible for purification of sewage in river is A. Hydrology B. Dissolved oxygen in water C. Temperature D. All the above
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 : 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
Last Answer : ANS: A
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 the flame of a miner’s safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains A. Hydrogen sulphide B. Carbon dioxide C. Methane D. Oxygen
Description : For the survival of fish in a river stream, the minimum dissolved oxygen is prescribed A. 3 ppm B. 4 ppm C. 5 ppm D. 10 ppm
Description : Fresh sewage may become stale in A. One hour B. Two to three hours C. Three to four hours D. Six hours
Description : Fresh sewage is generally A. Alkaline B. Acidic C. Highly decomposed D. A source of objectionable odour
Description : The effluent of a septic tank is A. Fit for discharge into any open drain B. Foul and contains dissolved and suspended solids C. As good as that from a complete treatment D. None 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 : A well oxidized sewage contains nitrogen mainly as A. Nitrates B. Nitrites C. Free ammonia D. None of these
Description : 1000 kg of sewage contains A. 0.112 kg in suspension B. 0.112 kg in solution C. 0.225 kg in solution D. Both A. and C. of above
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 : Facultative bacteria survive in A. The presence of oxygen B. The absence of oxygen C. Both cases A. and B. D. Neither A. nor B.
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 : Which one of the following gases is most significant as air pollutant? A. Carbondioxide B. Oxygen C. Nitrogen D. Sulphur-dioxide
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 : If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is A. 200 ppm B. 225 ppm C. 250 ppm D. None of these
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
Description : In a sludge tank, the gas mainly produced, is A. Oxygen B. Nitrogen C. Hydrogen D. Carbon dioxide
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 : 5 days-biochemical oxygen demand (BOD5) is taken at a temperature of A. 0°C B. 15°C C. 20°C D. 25°C
Description : The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known A. Bio-Chemical Oxygen Demand (B.O.D.) B. Dissolved Oxygen (D.O.) C. Chemical Oxygen Demand (C.O.D.) D. None of these
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 : Pick up the correct statement from the following: A. Anaerobic bacteria flourish in the absence of oxygen B. Aerobic bacteria flourish in the presence of oxygen C. Facultative bacteria flourish with or without oxygen 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 : Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. ... from 1 kg fresh juice is (A) 0.4 (B) 0.5 (C) 0.6 (D) 0.7
Last Answer : (D) 0.7
Description : Pick up the correct statement from the following: A. pH value indicates acidity and alkalinity of sewage B. In acidic sewage, the pH value is less than 7 C. In alkaline sewage, the pH value is more than 7 D. All the above
Description : pH value of sludge during alkaline regression stage, is A. More than 7 B. Less than 7 C. Less than 6 D. More than 6
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 : 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
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 : A nuisance is experienced in diluting water if dilution factor is less than A. 100 B. 60 C. 40 D. 20
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 : 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
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 : Hazen’s formula VS = 418 (GS – Gw)d [(3T + 70)/100] is used for the settlement velocity of the particles of diameter A. Less than 0.01 mm B. Less than 0.05 mm C. Less than 0.1 mm D. Greater than 0.1 mm
Description : The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is A. Vs = 418 (Gs – Gw) d [(3T + 70)/100] B. Vs = 418 (Gs – Gw)d² [(3T + 70)/100] C. Vs = 218 (Gs – Gw)d² [(3T + 70)/100] D. Vs = 218 (Gs – Gw)d [(3T + 70)/100]
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 sewer pipes of sizes less than 0.4 m diameter are designed as running full at maximum discharge B. The sewer pipes of sizes greater than 0.4 m ... discharge C. The minimum design velocity of sewer pipes is taken as 0.8 m/sec D. All the above
Description : Reema buys dress for 10% less than its value and sells it for 10% more than its value. His gain or loss percent is: A. no profit, no loss B. 20% profit C. less than 20% profit D. more than 20% profit
Last Answer : Answer – D (more than 20% profit) Explanation – Let the article be worth Rs. x. C.P. = 90% of Rs. x. = Rs.(9/10)x S.P. = 110% of Rs.x = Rs.(11/10)x Gain = Rs.11/10x- 9/10x=(1/5)x gain %=(2/5x) x (10/9x) x 100 =44.44% >20%
Description : 4Pradeep invested 20% more than Mohit. Mohit invested 10% less than Raghu. If the total sum of their investment is Rs. 17880, how much amount did Raghu invested? 1) Rs. 5000 2) Rs. 6500 3) Rs. 6000 4) Rs. 7500 5) Rs. 5500
Last Answer : Rs. 7500
Description : The concentration of agar to obtain semi solid media is A- 1.5-20%B- 0.5% or less C- >10% D- 10%but
Last Answer : 0.5% or less
Description : In basins subjected to strong winds and tide, the length of the berthing area should not be less than (A) The length of design vessel (B) The length of design vessel + 10% clearance ... The length of design vessel + 20% clearance between adjacent vessels (D) Twice the length of design vessel
Last Answer : (C) The length of design vessel + 20% clearance between adjacent vessels
Description : As per SEBI Guideline minimum Application money shall not be less than A. 25% of Issue price B. 10% of Issue price C. 20% of Issue price D. 6% of Issue price
Last Answer : A. 25% of Issue price
Description : Compared to fresh Water, the freezing point of sea water is - (1) Higher (2) Lower (3) Same (4) Depends on the sea from which the water is sourced
Last Answer : (2) Lower Explanation: Ocean water freezes just like freshwater, but at lower temperatures.