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This section includes 112 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
By aeration process, dissolved iron is oxidized into ____________ |
A. | Ferrous oxide |
B. | Ferric oxide |
C. | Ferrous hydroxide |
D. | Ferric hydroxide |
Answer» C. Ferrous hydroxide | |
2. |
In which process, the fluoride content of water is raised? |
A. | Chlorination |
B. | Fluoridation |
C. | Defluoridation |
D. | Flocculation |
Answer» C. Defluoridation | |
3. |
At which temperature, the bone is calcinated during defluoridation with calcium phosphate? |
A. | 100-200°C |
B. | 200-300°C |
C. | 400-600°C |
D. | 500-800°C |
Answer» D. 500-800°C | |
4. |
In which desalination process, the cooling of sea water is done to obtain fresh water? |
A. | Distillation |
B. | Electro-dialysis |
C. | Reverse osmosis |
D. | Freezing |
Answer» E. | |
5. |
Activated carbon can be applied to raw water ______ treatment process. |
A. | During |
B. | Ahead of |
C. | Before |
D. | After |
Answer» C. Before | |
6. |
Removal of manganese from water takes place at a pH of ______ |
A. | 1.5 |
B. | 3 |
C. | 6 |
D. | 9.4 |
Answer» E. | |
7. |
The presence of Sulfate iron in the water results in ____________ |
A. | Odorless water |
B. | Acidity in water |
C. | Colorless water |
D. | Growth of crenothrix in water mains |
Answer» C. Colorless water | |
8. |
Which of the following is used for the control of taste and odor in water? |
A. | Sedimentation |
B. | Coagulation |
C. | Filtration |
D. | Activated carbon |
Answer» E. | |
9. |
In Electro-dialysis, the electric energy which required is _____________ |
A. | Directly proportional to cation permeable membrane |
B. | Directly proportional to anion permeable membrane |
C. | Directly proportional to salt concentration |
D. | Inversely proportional to salt concentration |
Answer» D. Inversely proportional to salt concentration | |
10. |
Which of the following is not a property of activated carbon? |
A. | It is impermeable |
B. | It has many carbon atoms with free valencies |
C. | It is available in granular as well as powder form |
D. | It has a prolonged suspension |
Answer» B. It has many carbon atoms with free valencies | |
11. |
The thickness of the activated carbon filter bed is ____________ |
A. | 10-20cm |
B. | 30-80cm |
C. | 75-100cm |
D. | 40-50cm |
Answer» D. 40-50cm | |
12. |
_______ is produced by passing a carbonaceous material through a heating mechanism at high temperature. |
A. | Potassium per-manganate |
B. | Potassium dichromate |
C. | Activated carbon |
D. | Iodine |
Answer» D. Iodine | |
13. |
The pressure freezing process works on the vacuum free vapor compression principle. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» C. May be True or False | |
14. |
One cubic metre of bone can treat how much quantity of water containing 3.5 ppm of fluoride? |
A. | 10m³ |
B. | 100m³ |
C. | 1000m³ |
D. | 10000m³ |
Answer» C. 1000m³ | |
15. |
Which of the following is not a type of distillation plant? |
A. | Vertical tube evaporator |
B. | Multistage flash evaporator |
C. | Tube settler |
D. | Multi-effect multistage flash evaporator |
Answer» D. Multi-effect multistage flash evaporator | |
16. |
Which material is used for removing fluorides from hard water containing 3ppm of fluorides? |
A. | Lime |
B. | Copper sulfate |
C. | Synthetic tri-calcium phosphate |
D. | Bone charcoal |
Answer» B. Copper sulfate | |
17. |
The reddish tinge in the water is due to the presence of ____________ |
A. | Zinc |
B. | Copper |
C. | Iron |
D. | Manganese |
Answer» D. Manganese | |
18. |
Organic contaminants are removed from the water by the process of ______ |
A. | Water softening |
B. | Demineralization |
C. | Absorption |
D. | Adsorption |
Answer» E. | |
19. |
What is the size of the coarse screen used in pretreatment of water? |
A. | 25mm |
B. | 50mm |
C. | 75mm |
D. | 100mm |
Answer» B. 50mm | |
20. |
Which process of water treatment is done to avoid floating debris, branches, trees or other large particles suspended in water? |
A. | Screening |
B. | Aeration |
C. | Primary sedimentation |
D. | Secondary sedimentation |
Answer» B. Aeration | |
21. |
Which of the following is not used for defluoridation? |
A. | Calcium phosphate |
B. | Copper sulfate |
C. | Alum |
D. | Bone charcoal |
Answer» C. Alum | |
22. |
Aswan high dam is situated in |
A. | China |
B. | Egypt |
C. | America |
D. | Europe |
Answer» C. America | |
23. |
When small amounts of iron and manganese are present in water, they are removed by ____________ |
A. | Aeration |
B. | Coagulation |
C. | Manganese zeolite |
D. | Filtration |
Answer» D. Filtration | |
24. |
The fluoride concentration for prevention of dental caries is ____________ |
A. | 1mg/l |
B. | 2mg/l |
C. | 3mg/l |
D. | 4mg/l |
Answer» B. 2mg/l | |
25. |
In which desalination process, solar energy is used? |
A. | Reverse osmosis |
B. | Freezing |
C. | Electro-dialysis |
D. | Solar evaporation |
Answer» E. | |
26. |
The thickness of the layers of filter sand of zeolite softener is ____________ |
A. | 20cm |
B. | 30cm |
C. | 40cm |
D. | 100cm |
Answer» E. | |
27. |
When activated carbon is applied at more than one point, then it is called ________ |
A. | Dual treatment |
B. | Split treatment |
C. | Sludge treatment |
D. | Carbonaceous treatment |
Answer» C. Sludge treatment | |
28. |
Which of the following statement is wrong regarding hard water? |
A. | It causes more consumption of soap in laundry work |
B. | It causes difficulties in the manufacturing process |
C. | It increases the taste of food |
D. | It causes the formation of scales on the boilers |
Answer» D. It causes the formation of scales on the boilers | |
29. |
The temperature at which the softening of water takes place by lime soda process is ____________ |
A. | 10°-21°C |
B. | 20°-30°C |
C. | 39°-45°C |
D. | 90°C |
Answer» B. 20°-30°C | |
30. |
The permanent hardness can be removed by adding lime and soda. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» B. False | |
31. |
The chemical formula of Permutit is ____________ |
A. | SiOAl₂O₃Na₂O |
B. | SiO₂Al₂O₃Na₂O |
C. | SiO₂Al₂O₃NaO |
D. | SiO₃Al₂O₃Na₂O |
Answer» C. SiO₂Al₂O₃NaO | |
32. |
The color of the artificial zeolite permutit is ____________ |
A. | Grey |
B. | Yellow |
C. | Green |
D. | White |
Answer» E. | |
33. |
Natural zeolite is mainly processed from ____________ |
A. | White sand |
B. | Green sand |
C. | Grey sand |
D. | Red sand |
Answer» C. Grey sand | |
34. |
Permutit has an exchange value of ________ grams of hardness per m³ of zeolite. |
A. | 10,000 |
B. | 20,000-30,000 |
C. | 35,000-40,000 |
D. | 40,000-50,000 |
Answer» D. 40,000-50,000 | |
35. |
In which process of water softening, the chemicals are added to remove hardness from water? |
A. | Lime soda process |
B. | Zeolite process |
C. | Boiling |
D. | Demineralization process |
Answer» B. Zeolite process | |
36. |
Zeolites are complex compound of ____________ |
A. | Aluminium and lime |
B. | Silica and soda |
C. | Aluminium, silica and soda |
D. | Lime and soda |
Answer» D. Lime and soda | |
37. |
The sludge in water softening accelerator is deposited at ____________ |
A. | Sedimentation tank |
B. | Reaction zone |
C. | Concentrator |
D. | Secondary mixing zone |
Answer» D. Secondary mixing zone | |
38. |
Poor sanitation is an increasing problems of |
A. | South America and Africa |
B. | Middle East |
C. | Asia |
D. | All of these |
Answer» E. | |
39. |
Hot and wet climate are the best condition to grow |
A. | Plants |
B. | Animals |
C. | Insects, Bacteria, viruses |
D. | All of these |
Answer» E. | |
40. |
Softening chemicals, lime and soda do not depend on ____________ |
A. | Free carbon dioxide present |
B. | Non carbonate hardness |
C. | Total magnesium |
D. | Carbonate hardness |
Answer» E. | |
41. |
What is the pH at which recarbonation should be done? |
A. | 7 |
B. | 4.5 |
C. | 8.2 |
D. | 9.5 |
Answer» E. | |
42. |
Which form of solute stabilization occurs when water passes through limestone? |
A. | Chlorination |
B. | Liming |
C. | Re-carbonation |
D. | Super-chlorination |
Answer» C. Re-carbonation | |
43. |
Solids are removed from the water by which of the following unit operation? |
A. | Inter facial contact |
B. | Solid stabilization |
C. | Ion transfer |
D. | Solids transfer |
Answer» E. | |
44. |
In which type of aerator, the flow of water is divided into fine streams and small droplets? |
A. | Cascade aerator |
B. | Inclined apron aerator |
C. | Spray aerator |
D. | Gravel bed aerator |
Answer» B. Inclined apron aerator | |
45. |
Identify the incorrect statement regarding aeration process. |
A. | It removes taste and odor |
B. | It increases the dissolved oxygen content of water |
C. | It increases the carbon dioxide content of water |
D. | It is used for mixing chemicals with water |
Answer» D. It is used for mixing chemicals with water | |
46. |
The head loss through screen depends on _______________ |
A. | Shape of screen elements |
B. | Open area, block area |
C. | Approach velocity |
D. | Nature of their construction, approach velocity |
Answer» E. | |
47. |
Which of the following desalination method is more suitable for brackish water than sea water? |
A. | Distillation |
B. | Solar evaporation |
C. | Reverse osmosis |
D. | Freezing |
Answer» D. Freezing | |
48. |
What concentration of iron and manganese will cause unpleasant taste and odor of water? |
A. | 1ppm |
B. | 2ppm |
C. | 3ppm |
D. | >3ppm |
Answer» E. | |
49. |
Which of the following is the best evaporative desalinating method? |
A. | Vertical tube evaporator |
B. | Multistage flash evaporator |
C. | Tube settler |
D. | Multi-effect multistage flash evaporator |
Answer» C. Tube settler | |
50. |
The number of stages involved in the desalination using a multistage flash evaporator is _________________ |
A. | 20 |
B. | 38 |
C. | 49 |
D. | 69 |
Answer» E. | |