Environmental Engineering 20

Objective Questions and Answers of Civil Engineering: Environmental Engineering 20

Subject: Environmental Engineering 20

Part 20: Objective questions and answers of Environmental Engineering


Q1. If the sewage contains grease and fatty oils, these are removed in

a) Grit chambers

b) Detritus tanks

c) Skimming tanks

d) Sedimentation tanks


Q2. Septic tank is a

I) settling tank

Ii) digestion tank

Iii) aeration tank

The correct answer is

a) Only (i)

b) (i) and (ii)

c) (i) and (iii)

d) Only (iii)


Q3. The maximum efficiency of bod removal is achieved in

a) Oxidation pond

b) Oxidation ditch

c) Aerated lagoons

d) Trickling filters


Q4. In facultative stabilization pond, the sewage is treated by

a) Aerobic bacteria only

b) Algae only

c) Dual action of aerobic bacteria and anaerobic bacteria

d) Sedimentation


Q5. Composting and lagooning are the methods of

a) Sludge digestion

b) Sludge disposal

c) Sedimentation

d) Filtration


Q6. Aeration of water is done to remove

a) Odour

b) Colour

c) Bacteria’s

d) Hardness

e) Turbidity.


Q7. Time of concentration

a) Is the time taken, for precipitation

b) Duration of rainfall.

c) Time taken for all the ran off to reach the drain

d) Time taken for the storm water to travel from the most remote point to the drain.


Q8. In distribution pipes, drain valves are provided at

a) Lower point

b) Higher point

c) Junction points

d) Anywhere.


Q9. If four fires break out in a city of population 40 lakhs and if each hydrant has three streams and duration of each fire is four hours, the total quantity of water required, is

a) 1880 kilo liters

b) 2880 kilo liters

c) 3880 kilo liters

d) 4880 kilo liters.


Q10. Disinfection of drinking water, is done to remove

a) Odour

b) Bacteria’s

c) Turbidity

d) Colour.


Q11. The expected discharge to be obtained from an open well sunk in coarse sand is 0.0059 cume if the working depression head of the well is 3 m, the minimum diameter of the well, is

a) 2 m

b) 2.25 m

c) 2.50 m

d) 2.75 m

e) 3.00 m.


Q12. As per is : 1172-1963, water required per head per day for average domestic purposes, is

a) 50 liters

b) 65 liters

c) 85 liters

d) 105 liters

e) 135 liters.


Q13. Biochemical oxygen demand (B.O.D.) of safe drinking water must be

a) Nil

b) 5

c) 10

d) 15

e) 20


Q14. Asbestos pipes are

a) Light in weight and easy to transport

b) Highly resistant to corrosion

c) High flexible to accommodate deflection up to 12°

d) Very much smooth and hydraulically efficient

e) All the above.


Q15. By boiling water, hardness can be removed if it is due to

a) Calcium sulphate

b) Magnesium sulphate

c) Calcium nitrate

d) Calcium bicarbonate

e) None of these.


Q16. The least thickness of class b cast iron (spun) pipe, is

a) 7.2 mm

b) 7.9 mm

c) 8.6 mm

d) 10 mm.


Q17. For normal sludge, the value of sludge index for Indian conditions is

a) 0 to 50

b) 50 to 150

c) 150 to 350

d) 350 to 500


Q18. A pipe which is installed in the house drainage to preserve the water seal of traps is called

a) Vent pipe

b) Antisiphonage pipe

c) Waste pipe

d) Soil pipe


Q19. The pipe which is used to carry the discharge from sanitary fittings like bath rooms, kitchens etc. Is called

a) Waste pipe

b) Soil pipe

c) Vent pipe

d) Antisiphonage pipe


Q20. The process of lagooning is primarily a means of

a) Reducing the excessive flow in sewers

b) Disposing of sludge

c) Increasing the capacity of storage re-servoirs

d) Increasing flow of sewage through imhoff tanks


Part 20: Objective questions and answers of Environmental Engineering


Q1. Answer c


Q2. Answer b


Q3. Answer b


Q4. Answer c


Q5. Answer b


Q6. Answer a


Q7. Answer d


Q8. Answer a


Q9. Answer b


Q10. Answer b


Q11. Answer e


Q12. Answer e


Q13. Answer a


Q14. Answer e


Q15. Answer d


Q16. Answer c


Q17. Answer c


Q18. Answer b


Q19. Answer a


Q20. Answer b