MCQOPTIONS
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MCQOPTIONS
This section includes 78 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. |
The dose of KMnO4 required for disinfection of water is _______ ppm. |
| A. | 1-2 |
| B. | 2-3 |
| C. | 3-4 |
| D. | 4-7 |
| Answer» B. 2-3 | |
| 2. |
The number of organisms in disinfection process can be expressed by ____________ |
| A. | Cⁿ *tₚ = Constant |
| B. | Cⁿ / tₚ = Constant |
| C. | C^q * Nₚ = Constant |
| D. | C^q / Nₚ = Constant |
| Answer» D. C^q / Nₚ = Constant | |
| 3. |
What happens during the breakdown of ozone? |
| A. | CO₂ is formed |
| B. | Nascent oxygen is formed |
| C. | CO₂ and Nascent oxygen is formed |
| D. | Formation of oxygen and water takes place. |
| Answer» C. CO₂ and Nascent oxygen is formed | |
| 4. |
Ozone is a _______ allotrope of oxygen. |
| A. | Monoatomic |
| B. | Diatomic |
| C. | Triatomic |
| D. | Polyatomic |
| Answer» D. Polyatomic | |
| 5. |
When the coefficient of dilution is 1, then which of the following statement is correct? |
| A. | Time of contact is more important than dosage |
| B. | The dosage is more important than time of contact |
| C. | Concentration and time are equally important |
| D. | Efficiency of dilution decreases. |
| Answer» D. Efficiency of dilution decreases. | |
| 6. |
The integration of the expression of Chicks law is given by ____________ |
| A. | N1/N = e^kt |
| B. | N1/N = kt |
| C. | N1/N = k/t |
| D. | N1/N = e^(-kt) |
| Answer» E. | |
| 7. |
Addition of KMnO₄ to water imparts _____ color. |
| A. | Blue |
| B. | Red |
| C. | Pink |
| D. | White |
| Answer» D. White | |
| 8. |
At what pH, the E-Coli bacteria will die in the water? |
| A. | 6 |
| B. | 7 |
| C. | 9 |
| D. | >9.5 |
| Answer» E. | |
| 9. |
The chlorine, which serves as a disinfectant is ___________ |
| A. | Free chlorine |
| B. | Free Residual chlorine |
| C. | Chlorine demand |
| D. | Residual demand |
| Answer» C. Chlorine demand | |
| 10. |
At what pH, chlorine exists as molecular chlorine? |
| A. | 3 |
| B. | 5 |
| C. | <5 |
| D. | <10 |
| Answer» D. <10 | |
| 11. |
According to which of the following, organism destroyed by disinfection is proportional to organism remaining? |
| A. | Hazens equation |
| B. | Chicks law |
| C. | Darcy’s law |
| D. | Rose equation |
| Answer» C. Darcy’s law | |
| 12. |
What is the chemical formula of bleaching powder? |
| A. | Ca (OCl)₂ |
| B. | Ca (OCl) |
| C. | Ca (OCl)₃ |
| D. | CaCl₂ |
| Answer» B. Ca (OCl) | |
| 13. |
The ozone generators can convert ____ % of feed oxygen into ozone. |
| A. | 1 |
| B. | 5 |
| C. | 1-4 |
| D. | 10 |
| Answer» D. 10 | |
| 14. |
For changing the concentration of disinfectant, the disinfecting efficiency is expressed by ____________ |
| A. | C n *t p = Constant |
| B. | C n/ t p = Constant |
| C. | C q * Np = Constant |
| D. | C q / Np = Constant |
| Answer» B. C n/ t p = Constant | |
| 15. |
The chemical formula of iodate is __________ |
| A. | HIO₃ |
| B. | HIO |
| C. | HIO₂ |
| D. | H₂IO₂ |
| Answer» B. HIO | |
| 16. |
The dimensional formula of rate constant used in Chicks law is ____________ |
| A. | 1/t |
| B. | 1/t² |
| C. | 1/t³ |
| D. | t² |
| Answer» B. 1/t² | |
| 17. |
What happens to the hypoiodous acid when the pH is over 8? |
| A. | HIO is stable |
| B. | Formation of hypoiodite ion takes place |
| C. | Formation of iodine and hypoiodite ion takes place |
| D. | Formation of iodine and iodate takes place |
| Answer» E. | |
| 18. |
The hypochlorous acid is ______ times effective as hypochorite ions. |
| A. | 10 |
| B. | 30 |
| C. | 50 |
| D. | 80 |
| Answer» E. | |
| 19. |
At what pH, the dissociation of hypoiodous acid takes place? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» E. | |
| 20. |
Bleaching powder contains ______ of available chlorine. |
| A. | 16% |
| B. | 33.3% |
| C. | 66.6% |
| D. | 99.9% |
| Answer» C. 66.6% | |
| 21. |
The water is free from oxidizable materials. What is the dosage of ozone required? |
| A. | 0.01ppm |
| B. | 0.1-0.2ppm |
| C. | 0.2-0.3ppm |
| D. | 0.4-0.5ppm |
| Answer» D. 0.4-0.5ppm | |
| 22. |
The temperature of disinfection is inversely proportional to the killing of organisms. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 23. |
Which method of disinfection is mainly used in rural areas? |
| A. | Boiling method |
| B. | Excess lime treatment |
| C. | Potassium permanganate treatment |
| D. | Silver treatment |
| Answer» D. Silver treatment | |
| 24. |
Normally, the ratio of ammonia and chlorine in chloramine is? |
| A. | 1:1 |
| B. | 1:2 |
| C. | 1:4.5 |
| D. | 1:3.5 |
| Answer» D. 1:3.5 | |
| 25. |
The normal dose of chlorine during plain chlorination is ___________ |
| A. | 0.5-1ppm |
| B. | 0.1-0.2ppm |
| C. | 0.1-0.5ppm |
| D. | 1-2ppm |
| Answer» B. 0.1-0.2ppm | |
| 26. |
_________ is the application of chlorine before filtration. |
| A. | Plain chlorination |
| B. | Pre chlorination |
| C. | Super chlorination |
| D. | Double chlorination |
| Answer» C. Super chlorination | |
| 27. |
What is the contact period for disinfection with chloramine? |
| A. | 1hour |
| B. | 2hours |
| C. | 3hours |
| D. | 4hours |
| Answer» C. 3hours | |
| 28. |
Which type of chloramine is formed when pH of water is 4.4? |
| A. | Monachloramine |
| B. | Dichloramine |
| C. | Trichloramine |
| D. | Both monochloramine and dichloramine |
| Answer» C. Trichloramine | |
| 29. |
Sunlight is a ________ method of disinfection. |
| A. | Physical |
| B. | Chemical |
| C. | Mechanical |
| D. | Electrical |
| Answer» B. Chemical | |
| 30. |
Which of the following is the expression of Chicks law? |
| A. | Dy/Dt = k (N – y) |
| B. | Dy/Dt = k/(N – y) |
| C. | Dy/Dt = k (N + y) |
| D. | Dy/Dt = k (N * y) |
| Answer» B. Dy/Dt = k/(N – y) | |
| 31. |
The process of chlorination with hypochlorites is called ___________ |
| A. | Super chlorination |
| B. | Pre chlorination |
| C. | Post chlorination |
| D. | Hypo-chlorination |
| Answer» E. | |
| 32. |
The chemical formula of hypoiodous acid is __________ |
| A. | H₂IO |
| B. | H₂I |
| C. | HIO |
| D. | HI₂ |
| Answer» D. HI₂ | |
| 33. |
The dose of KMnO₄ required for disinfection of water is _______ ppm. |
| A. | 1-2 |
| B. | 2-3 |
| C. | 3-4 |
| D. | 4-7 |
| Answer» B. 2-3 | |
| 34. |
The depth of water while using ultra violet ray treatment for disinfection should be ____ |
| A. | 35cm |
| B. | 46cm |
| C. | 28cm |
| D. | 10cm |
| Answer» E. | |
| 35. |
What happen to the concentration of iodine when the pH is between 6 and 8? |
| A. | I₂ decreases whereas HIO increases |
| B. | I₂ increases, whereas HIO decreases |
| C. | Both I₂ and HIO increases |
| D. | Both I₂ and HIO decreases |
| Answer» B. I₂ increases, whereas HIO decreases | |
| 36. |
The expression loge N1/N = – kt m Where m is a constant such that m>1 represents ____________ |
| A. | Rate of the kill will remains constant with time |
| B. | Rate of the kill will increase with time |
| C. | Rate of the kill will decrease with time |
| D. | Rate of the kill is directly proportional to time |
| Answer» C. Rate of the kill will decrease with time | |
| 37. |
a HIO + b OH⁻ HIO₃ + b H₂O + b I⁻. What are the values of a and b respectively in the above equation? |
| A. | 1, 2 |
| B. | 1, 3 |
| C. | 3, 2 |
| D. | 3, 1 |
| Answer» D. 3, 1 | |
| 38. |
The dosage of ozone for municipal water treatment is __________ |
| A. | 0.5 ppm |
| B. | 1ppm |
| C. | 1.5 ppm |
| D. | 2ppm |
| Answer» D. 2ppm | |
| 39. |
_______ is the application of chlorine beyond the stage of the break point. |
| A. | Plain chlorination |
| B. | Pre chlorination |
| C. | Super chlorination |
| D. | Double chlorination |
| Answer» D. Double chlorination | |
| 40. |
Which of the following regarding break point chlorination is wrong? |
| A. | It will have adequate chlorine residual |
| B. | It will remove manganese |
| C. | It will remove taste and odor |
| D. | It is determined by physical test |
| Answer» E. | |
| 41. |
The normal dose of chlorine during break point chlorination is ____________ |
| A. | 0.5-1ppm |
| B. | 0.1-0.2ppm |
| C. | 3-7ppm |
| D. | 1-2ppm |
| Answer» C. 3-7ppm | |
| 42. |
The contact time for disinfection by free chlorine is ______________ |
| A. | 20 minutes |
| B. | 30 minutes |
| C. | 40 minutes |
| D. | 60minutes |
| Answer» B. 30 minutes | |
| 43. |
The efficiency of chlorine increase by ______________ |
| A. | Presence of metallic compounds |
| B. | When the pH of the water increases |
| C. | When the pH of the water decreases |
| D. | Turbid water |
| Answer» D. Turbid water | |
| 44. |
The amount of hypochlorous acid formed when pH of water is 8 is _______________ |
| A. | 95% of total free chlorine |
| B. | 80% of total free chlorine |
| C. | 30% of total free chlorine |
| D. | 5% of total free chlorine |
| Answer» D. 5% of total free chlorine | |
| 45. |
The presence of metallic compounds in water _______ the efficiency of chlorine. |
| A. | Decreases |
| B. | Increases |
| C. | Slightly decreases |
| D. | Remains constant |
| Answer» B. Increases | |
| 46. |
When turbidity in water increases, the efficiency of chlorine? |
| A. | Decreases |
| B. | Increases |
| C. | Slightly increases |
| D. | Remains constant |
| Answer» B. Increases | |
| 47. |
At what pH, chlorine in water acts as only hypochlorite ions? |
| A. | <5 |
| B. | >5 |
| C. | >10 |
| D. | <3 |
| Answer» D. <3 | |
| 48. |
Which color is formed when orthotolidine is oxidized by chlorine? |
| A. | Yellow |
| B. | Orange |
| C. | Green |
| D. | Blue |
| Answer» B. Orange | |
| 49. |
When the pH is between 5 and 10, the chlorine in the water acts as ______ |
| A. | Hypochlorous acid |
| B. | Hypochlorite ions |
| C. | Molecular chlorine |
| D. | Hypochlorous acid hypochlorite ions |
| Answer» E. | |
| 50. |
Which of the following is most effective in the killing of bacteria present in water? |
| A. | Nascent oxygen |
| B. | Chlorine |
| C. | HOBr |
| D. | I2 |
| Answer» B. Chlorine | |