131. Drop manholes at the junctions of sewer lines, are provided if________________? September 7, 2025 by Admin A. Invert level of a branch sewer is more than 60 cm that of the main sewer B. Sewer line runs along a main road C. Ordinary manhole cannot be built D. Two sewer lines intersect ✅ The correct answer is option A.
132. The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is_______________? September 7, 2025 by Admin A. 25 % B. 50 % C. 10 % D. 5 % ✅ The correct answer is option B.
133. The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope_________________? September 7, 2025 by Admin A. 1 in 5 B. 1 in 10 C. 1 in 15 D. 1 in 20 ✅ The correct answer is option B.
134. Removal of oil and grease from sewage, is known____________________? September 7, 2025 by Admin A. Screening B. Skimming C. Filtration D. None of these ✅ The correct answer is option B.
135. A drop manhole is provided if__________________? September 7, 2025 by Admin A. A sewer drops from a height B. A branch sewer joins the main sewer at higher level C. A lamp is inserted to check obstruction D. None of these ✅ The correct answer is option B.
136. The gas which may cause explosion in sewers, is_________________? September 7, 2025 by Admin A. Carbondioxide B. Methane C. Ammonia D. Carbon monoxide ✅ The correct answer is option B.
137. To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of_______________? September 7, 2025 by Admin A. Hydrochloric acid B. Sulphuric acid C. Nitric acid D. Citric acid ✅ The correct answer is option B.
138. Lead acetate test in sewer manhole is done to test the presence of ____________________? September 7, 2025 by Admin A. Methane gas B. Hydrogen sulphide C. Carbondioxide gas D. Diesel vapours ✅ The correct answer is option B.
139. What refers to the residual value of a company’s assets after all outside liabilities (shareholders excluded) have been allowed for ? September 7, 2025 by Admin A. Dividend B. Equity C. Return D. Par value ✅ The correct answer is option B.
140. Centre of pressure compared to e.g. is______________? September 7, 2025 by Admin A. above it B. below it C. at same point D. above or below depending on area of body ✅ The correct answer is option B.