Environmental Engineering 19

Objective Questions and Answers of Civil Engineering: Environmental Engineering 19

Subject: Environmental Engineering 19

Part 19: Objective questions and answers of Environmental Engineering


Q1. Scour valves are provided

a) At street corners to control the flow of water

b) At every depression and dead ends to drain out the waste water that may collect there

c) At the foot of rising main along the slope to prevent back running of water

d) At every summit of rising mains


Q2. A pipe conveying sewage from plumbing system of a single building to common sewer or point of immediate disposal is called

a) House sewer

b) Lateral sewer

c) Main sewer

d) Submain sewer


Q3. 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


Q4. Which of the following sewers is preferred for combined system of sewage?

a) Circular sewer

b) Egg shaped sewer

c) Rectangular sewer

d) None of the above


Q5. The water carriage system of collection of waste product

a) Is cheaper in initial cost than dry conservancy system

b) Requires treatment before disposal

c) Creates hygenic problem

d) All of the above


Q6. The time of concentration is defined as

a) The time taken by rainfall water to run from most distant point of water shed to the inlet of sewer

b) The time required for flow of water in sewer to the point under consideration

c) Sum of (a) and (b)

d) Difference of (a) and (b)


Q7. The self-cleansing velocity for all sewers in India is usually

a) Less than 1.0 m/sec

b) 1.0 m/sec to 1.2 m/sec

c) 1.5 m/sec to 2.0 m/sec

d) 3.0 m/sec to 3.5 m/sec


Q8. The design discharge for the separate sewer system shall be taken as

a) Equal to dry weather flow (dwf)

b) 2xdwf

c) 3 x dwf

d) 6xdwf


Q9. The minimum and maximum diameters of sewers shall preferably

a) 15 cm and 100 cm

b) 15 cm and 300 cm

c) 30 cm and 450 cm

d) 60 cm and 300 cm


Q10. Most suitable section of sewer in separate sewage system is

a) Rectangular section

b) Circular section

c) Standard form of egg shaped sewer

d) Modified egg shaped section


Q11. The velocity of flow does not depend on

a) Grade of sewer

b) Length of sewer

c) Hydraulic mean depth of sewer

d) Roughness of sewer


Q12. The hydraulic mean depth (hmd) for an egg-shaped sewer flowing two-third full is

a) Equal to hmd when flowing full

b) Less than hmd when flowing full

c) Greater than hmd when flowing full

d) None of the above


Q13. The type of sewer which is suitable for both combined and separate system is

a) Circular sewer

b) Egg shaped sewer

c) Horse-shoe type sewer

d) Semi-elliptical sewer


Q14. The pathogens can be killed by

a) Nitrification

b) Chlorination

c) Oxidation

d) None of the above


Q15. Sewage treatment units are normally designed for

a) 5-10 years

b) 15-20 years

c) 30-40 years

d) 40-50 years


Q16. Settling velocity increases with

a) Specific gravity of solid particles

b) Size of particles

c) Depth of tank

d) Temperature of liquid


Q17. The correct relation between theoretical oxygen demand (tod), biochemical oxygen demand (bod) and chemical oxygen demand (cod) is given by

a) Tod>bod>cod

b) Tod>cod>bod

c) Bod>cod>tod

d) Cod>bod>tod


Q18. If biochemical oxygen demand (bod) of a town is 20000 kg/day and bod per capita per day is 0.05 kg, then population equivalent of town is

a) 1000

b) 4000

c) 100000

d) 400000


Q19. The ratio of 5 day bod to ultimate bod is about

a) 1/3

b) 2/3

c) 3/4

d) 1.0


Q20. The minimum dissolved oxygen which should always be present in water in order to save the aquatic life is

a) 1 ppm

b) 4 ppm

c) 10 ppm

d) 40 ppm


Part 19: Objective questions and answers of Environmental Engineering


Q1. Answer b


Q2. Answer a


Q3. Answer b


Q4. Answer b


Q5. Answer b


Q6. Answer c


Q7. Answer b


Q8. Answer d


Q9. Answer b


Q10. Answer b


Q11. Answer b


Q12. Answer c


Q13. Answer b


Q14. Answer b


Q15. Answer b


Q16. Answer c


Q17. Answer b


Q18. Answer d


Q19. Answer b


Q20. Answer b