A. directly proportional to BOD satisfied
B. directly proportional to BOD remain-ing
C. inversely proportional to BOD satisfied
D. inversely proportional to BOD re-maining
✅ The correct answer is option B.
Environmental Engineering MCQs
42. Which of the following compounds is widely used for algae control ?
A. sodium sulphate
B. copper sulphate
C. sodium chloride
D. calcium chloride
✅ The correct answer is option B.
43. An egg shaped section of sewer________________?
A. is economical than circular section
B. provides self cleansing velocity at low discharges
C. is more stable than circular section
D. is easy to construct
✅ The correct answer is option B.
44. The suitable method of forecasting popu¬lation for a young and rapidly increasing city is_________________?
A. arithmetical increase method
B. geometrical increase method
C. incremental increase method
D. graphical method
✅ The correct answer is option B.
45. Most of the bacteria in sewage are______________?
A. parasitic
B. saprophytic
C. pathogenic
D. anaerobic
✅ The correct answer is option B.
46. The ratio of 5 day BOD to ultimate BOD is about_______________?
A. 1/3
B. 2/3
C. 3/4
D. 1.0
✅ The correct answer is option B.
47. The pathogens can be killed by_______________?
A. nitrification
B. chlorination
C. oxidation
D. none of the above
✅ The correct answer is option B.
48. The suitable layout of distribution system for a city with roads of rectangular pattern is______________?
A. grid iron system
B. dead end system
C. ring system
D. radial system
✅ The correct answer is option A.
49. The maximum efficiency of BOD removal is achieved in______________?
A. oxidation pond
B. oxidation ditch
C. aerated lagoons
D. trickling filters
✅ The correct answer is option B.
50. Average rate of water consumption perhead per day as per Indian Standard is______________?
A. 100 litres
B. 135 litres
C. 165 litres
D. 200 litres
✅ The correct answer is option B.