Waste water Engineering Mock test – 3 || Civil Engineering Mock tests Welcome to your Waste Water Engineering Mock test - 3 Take an exciting test in Waste water Engineering You have only 20 mins to complete the test (25 Questions) Wish you all the best!!! Name Email 1) The pH value of fresh sewage is usually A. equal to 7 B. more than 7 C. less than 7 D. equal to zero.2) Primary treatment of sewage consists of removal of A. large suspended organic solids B. oil and grease C. sand and girt D. floating materials3) 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.4) 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.5) Lead caulked joints are used for laying A. stone ware pipes B. earthern ware pipes C. C.I. pipes D. G.I. pipes.6) 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 cleansing velocity C. The sewers may be carried up and down the hills and valleys D. The sewer pipes are generally laid along level hills7) The ratio of the diameter of a circular section and the side of a square section hydraulically equivalent, is A. 1.095 B. 1.085 C. 1.075 D. 1.0658) The algae dies out in the zone of A. degradation B. active decomposition C. recovery D. cleaner water.9) If the peak discharge of a storm water drain (S.W. Drain) is e.xpected to exceed 150 cumecs, the free board to be provided, is A. 100 cm B. 90 cm C. 80 cm D. 50 cm.10) Ventilating shafts are provided to a sewer line at every A. 100 m B. 150 m C. 200 m D. 300 m11) Sluge banks are formed if sewage is disposed of in A. rivers B. seas C. lakes D. none of these.12) PH value of sludge during alkaline regression stage, is A. more than 7 B. less than 7 C. less than 6 D. more than 6.13) Hydraulic mean radius is A. mean radius of sewer B. difference in heads between two points in circular pipes C. mean of radii in a pipe line of varying cross-sections D. cross-sectional area/wetted perimeter.14) 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. 3.015) The moisture content of a sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is A. 25% B. 50% C. 10% D. 5%.16) The self-cleansing velocity of water flowing through pipe lines, is A. 2 metres/sec B. 1 metre/sec C. 0.5 metre/sec D. 0.25 metre/sec.17) 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.18) PH value of sludge during alkaline regression stage, is A. more than 7 B. less than 7 C. less than 6 D. more than 6.19) The recommended detention period for grit chambers is A. 1 minute B. 2 minutes C. 3 minutes D. 5 minutes.20) Depletion of ozone layer in the outer atmosphere may cause A. lung cancer B. skin cancer C. bronchitis D. heart disorder.21) The pH value of sewage is determined with the help of A. Imhoff Cone B. turbidimeter C. potentiometer D. none of these.22) The sewer pipe which carries sewage from a building for immediate disposal is A. house sewer B. lateral sewer C. intercepting sewer D. main sewer.23) 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 shaped24) 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.25) The sludge does not contain waste water from A. bath rooms B. wash basins C. kitchen sinks D. toilets.26) Which one of the following part of human body withstands minimum radiation A. thyroid B. kidneys C. eyes D. ovaries/testis.