461. In a fully mechanised composting plant, involves________________? A. Mechanized receipt B. Mechanized segregation C. Mechanized pulverising of refuse D. All of these ✅ The correct answer is option D.
462. ¾th or ¼th extra space is left in sewer pipes at maximum discharge for_________________? A. Low estimates of the average and maximum flows B. Large scale infiltration of storm water C. Unexpected increase in population D. All the above ✅ The correct answer is option D.
463. running partially full with central angle , For a circular sewer of diameter__________________? A. d/D = ½ (1 – – B. a/A C. r/R = [1 – D. All the above ✅ The correct answer is option D.
464. Which one of the following statements is correct ? A. During the day, earth reflects solar radiation B. During the day, earth reflects both solar radiations the emission from its surface C. During the night, earth emits radiation from its surface D. All of these ✅ The correct answer is option D.
465. According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to __________________? A. the weight of the body B. more than the weight of the body C. less than the weight of the body D. weight of the fluid displaced by the body ✅ The correct answer is option D.
466. Which one of the following statement is correct ? A. Radiant energy expressed in Joules, is the energy associated with electromagnetic radiation B. The rate of transfer of radiant energy is called flux and is expressed in watts C. The radiant energy which falls upon a surface is termed as irradiance D. All of these ✅ The correct answer is option D.
467. 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 ✅ The correct answer is option D.
468. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal__________________? A. ratio of inertial force to force due to viscosity B. ratio of inertial force to force due to gravitation C. ratio of inertial force to force due to surface tension D. all the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity ✅ The correct answer is option D.
469. 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 ✅ The correct answer is option D.
470. 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 ✅ The correct answer is option D.