MCQOPTIONS
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MCQOPTIONS
This section includes 50 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Science knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The minimum depth to which sewage should be discharged of sea water is |
| A. | 0.5m |
| B. | 1m |
| C. | 2m |
| D. | 3m |
| Answer» E. | |
| 2. |
The lakes are classified into how many types on the basis of productivity? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 6 |
| Answer» D. 6 | |
| 3. |
The tolerance limit of COD of sewage to be discharged in sea water is |
| A. | 250ppm |
| B. | 100ppm |
| C. | 40ppm |
| D. | 20ppm |
| Answer» B. 100ppm | |
| 4. |
When the BOD of wastewater increases, then |
| A. | Rate of reaeration decreases |
| B. | Rate of oxygen deficit increases |
| C. | Rate of oxygen deficit decreases |
| D. | Amount of oxygen in wastewater increases |
| Answer» C. Rate of oxygen deficit decreases | |
| 5. |
The reoxygenation constant at temperature 'T' is expressed by |
| A. | KRT = KR20 (1.016)T |
| B. | KRT = KR20 (1.047) T-20 |
| C. | KRT = KR20 (1.016)T-20 |
| D. | KRT = KR20 (1.047)T |
| Answer» D. KRT = KR20 (1.047)T | |
| 6. |
State whether the following statement is true or false.The eutrophication process leads to turbidity in lakes. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 7. |
State whether the following statement is true or false.The turbulence decreases the DO content of water. |
| A. | True |
| B. | False |
| Answer» C. | |
| 8. |
The depth of Euphotic zone is measured by |
| A. | Calorimeter |
| B. | Turbidity meter |
| C. | Secchi disk |
| D. | Radar |
| Answer» D. Radar | |
| 9. |
Which type of pollution is a Cultural eutrophication? |
| A. | Water pollution |
| B. | Noise pollution |
| C. | Thermal pollution |
| D. | Soil pollution |
| Answer» B. Noise pollution | |
| 10. |
State whether the following statement is true or false.Rate of aeration is independent of the D.O content of wastewater. |
| A. | True |
| B. | False |
| Answer» C. | |
| 11. |
The design velocity of flow of a detritus tank is |
| A. | 1m/Sec |
| B. | 1.2m/Sec |
| C. | 0.9m/Sec |
| D. | 0.5m/Sec |
| Answer» D. 0.5m/Sec | |
| 12. |
Which of the following device is used for removal of oil and grease? |
| A. | Skimming tank |
| B. | Grit chambers |
| C. | Tube settlers |
| D. | Flocculator |
| Answer» B. Grit chambers | |
| 13. |
In which of the following, large impurities are attached with air bubbles to remove it from the wastewater? |
| A. | Sludge digestion tank |
| B. | Primary sedimentation |
| C. | Vacuum floatation |
| D. | Oxidation pond |
| Answer» D. Oxidation pond | |
| 14. |
Which of the following has minimum detention period? |
| A. | Grit chamber |
| B. | Sedimentation tank |
| C. | Oxidation ditch |
| D. | Oxidation pond |
| Answer» B. Sedimentation tank | |
| 15. |
The dimension formula of kinematic viscosity is |
| A. | L-1T |
| B. | ML-1T-1 |
| C. | ML-2T-2 |
| D. | L2T-1 |
| Answer» E. | |
| 16. |
The aerobic decomposition of nitrogenous organic matter gives |
| A. | Nitrites and water |
| B. | Carbon dioxide and water |
| C. | Nitrates and ammonia |
| D. | Nitrogen and ammonia |
| Answer» D. Nitrogen and ammonia | |
| 17. |
The average standard BOD of domestic sewage is measured in |
| A. | ppm |
| B. | Kg/day |
| C. | Kg per person per day |
| D. | Number of persons per day |
| Answer» D. Number of persons per day | |
| 18. |
State whether the following statement is true or false.The fresh sewage is acidic in nature. |
| A. | True |
| B. | False |
| Answer» C. | |
| 19. |
The expression of relative stability at 20oC is given by |
| A. | S = (1-(0.794)T20 |
| B. | S = 100 (1-(0.794) T20) |
| C. | S = 1-(0.794) T20 |
| D. | S = 100 (0.794) T20 |
| Answer» C. S = 1-(0.794) T20 | |
| 20. |
The nitrogenous demand occurs due to oxidation of |
| A. | Ammonia |
| B. | Sulfur |
| C. | Organic matter |
| D. | Nitrogen |
| Answer» B. Sulfur | |
| 21. |
The nitrogenous demand begins after how many days? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 5 |
| Answer» E. | |
| 22. |
In India, the average temperature of sewage is |
| A. | 10oC |
| B. | 20oC |
| C. | 40oC |
| D. | 80oC |
| Answer» C. 40oC | |
| 23. |
The oxidizing agent used in COD test is |
| A. | Potassium chloride |
| B. | Potassium per-manganate |
| C. | Potassium chromate |
| D. | Potassium dichromate |
| Answer» E. | |
| 24. |
Partially oxidized sewage contains |
| A. | Nitrites and Nitrates |
| B. | Nitrates and sulfur |
| C. | Sulfates and nitrates |
| D. | Nitrites and sulfur |
| Answer» E. | |
| 25. |
The decomposition of nitrogenous organic matter in the absence of oxygen gives |
| A. | Nitrites and water |
| B. | Carbon dioxide and water |
| C. | Nitrates and ammonia |
| D. | Nitrogen, ammonia and organic acids |
| Answer» E. | |
| 26. |
_______ indicates the freshness of sewage. |
| A. | Turbidity |
| B. | Color |
| C. | Temperature |
| D. | COD |
| Answer» C. Temperature | |
| 27. |
The aerobic decomposition of sulfurous organic matter gives |
| A. | Nitrites and water |
| B. | Carbon dioxide and water |
| C. | Sulfates and water |
| D. | Nitrogen and Ammonia |
| Answer» D. Nitrogen and Ammonia | |
| 28. |
State whether the following statement is true or false.The value of deoxygenation constant is independent of the temperature. |
| A. | True |
| B. | False |
| Answer» C. | |
| 29. |
The carbonaceous demand occurs due to oxidation of |
| A. | Ammonia |
| B. | Sulfur |
| C. | Organic matter |
| D. | Nitrogen |
| Answer» D. Nitrogen | |
| 30. |
5 days BOD at 20oC is ___ of total demand. |
| A. | 0.2 |
| B. | 0.47 |
| C. | 0.68 |
| D. | 1 |
| Answer» D. 1 | |
| 31. |
The detention period of detritus tank is |
| A. | 40 seconds |
| B. | 1 minute |
| C. | 3 minute |
| D. | 1 hour |
| Answer» D. 1 hour | |
| 32. |
The dimension formula of dynamic viscosity is |
| A. | ML-1T |
| B. | ML-1T-1 |
| C. | ML-2T-2 |
| D. | ML-1T-3 |
| Answer» C. ML-2T-2 | |
| 33. |
The coefficient of drag for a transition settling is |
| A. | CD = 18.5/R0.6 |
| B. | CD = 24/R |
| C. | CD = 8.5/R0.6 |
| D. | CD = R/24 |
| Answer» B. CD = 24/R | |
| 34. |
A pressure difference of ___ is applied to vacuum floatation method to remove impurities from sewage. |
| A. | 0.5 atm |
| B. | 1 atm |
| C. | 1.5 atm |
| D. | 2 atm |
| Answer» C. 1.5 atm | |
| 35. |
The permissible dose of chloride in domestic sewage is |
| A. | 120ppm |
| B. | 10ppm |
| C. | 1ppm |
| D. | 250ppm |
| Answer» B. 10ppm | |
| 36. |
______ represents the number of dilutions required to reduce odor. |
| A. | Dispersion |
| B. | Threshold odor number |
| C. | BOD |
| D. | COD |
| Answer» C. BOD | |
| 37. |
Which of the following expression is correct regarding deoxygenation constant where symbols have their usual meaning? |
| A. | KDT = KD20 + (1.047)T-20 |
| B. | KDT = KD20 / (1.047) T-20 |
| C. | KDT = KD20 (1.047) T-20 |
| D. | KDT = KD20 (1.04T |
| Answer» D. KDT = KD20 (1.04T | |
| 38. |
COD is abbreviated as |
| A. | Chemical oxygen demand |
| B. | Complex oxygen demand |
| C. | Customary oxygen demand |
| D. | Chemical oxygen deficit |
| Answer» B. Complex oxygen demand | |
| 39. |
________ is used to find the D.O content of sewage. |
| A. | Winkler method |
| B. | Chromatography |
| C. | Kjeldahl method |
| D. | Olfactometer |
| Answer» C. Kjeldahl method | |
| 40. |
The energy released during the aerobic oxidation of organic matter is _____ kilo calories. |
| A. | 26 |
| B. | 254 |
| C. | 360 |
| D. | 484 |
| Answer» E. | |
| 41. |
Identify the incorrect statement from the following? |
| A. | High odor intensity indicates odorless water |
| B. | Fresh sewage is odorless |
| C. | Turbidity can be measured by turbidity rod |
| D. | NTU is a unit of turbidity |
| Answer» B. Fresh sewage is odorless | |
| 42. |
The decomposition of sewage takes place, causing a pungent smell. Which of the following causes the pungent smell? |
| A. | CO2 |
| B. | H2SO4 |
| C. | HCL |
| D. | H2S |
| Answer» E. | |
| 43. |
The relation between dynamic and kinematic viscosity is given by |
| A. | Dynamic viscosity = Kinematic viscosity * Density of water |
| B. | Kinematic viscosity = Dynamic viscosity + Density of water |
| C. | Dynamic viscosity = Kinematic viscosity * Density of water |
| D. | Dynamic viscosity = Kinematic viscosity / Density of water |
| Answer» D. Dynamic viscosity = Kinematic viscosity / Density of water | |
| 44. |
Solids are removed from the wastewater by which of the following unit operation? |
| A. | Inter facial contact |
| B. | Solid stabilization |
| C. | Ion transfer |
| D. | Solids transfer |
| Answer» E. | |
| 45. |
State whether the following statement is True or False.Dealkalization results in removal of all the ions from the wastewater. |
| A. | True |
| B. | False |
| Answer» C. | |
| 46. |
The head loss through the screen is given by HL = k* (Vt2 – Va2), where Vt and Va are velocities through and above the screen respectively. What is the value of constant k? |
| A. | 1 |
| B. | 0.005 |
| C. | 0.0729 |
| D. | 0.0236 |
| Answer» D. 0.0236 | |
| 47. |
Which form of solute stabilization occurs when effluent passes through limestone? |
| A. | Chlorination |
| B. | Liming |
| C. | Re-carbonation |
| D. | Super-chlorination |
| Answer» C. Re-carbonation | |
| 48. |
State whether the following statement is true or false.BOD of wastewater having aerobic oxidation is more than that, having anaerobic oxidation. |
| A. | True |
| B. | False |
| Answer» C. | |
| 49. |
The expression of relative stability at 37oC is given by |
| A. | S = (1-(0.794)T37 |
| B. | S = 100 (1-(0.794) T37) |
| C. | S = 1-(0.794) T20 |
| D. | S = 100 (1-(0.630)T37) |
| Answer» E. | |
| 50. |
Imhoff cone is used to measure the _______ |
| A. | Suspended solids |
| B. | Settleable solids |
| C. | Dissolved solids |
| D. | Total solids |
| Answer» C. Dissolved solids | |