MCQOPTIONS
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MCQOPTIONS
This section includes 24 Mcqs, each offering curated multiple-choice questions to sharpen your Waste Water Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following represents the impeller shaft in the following figure?Figure: Flash mixer |
| A. | F |
| B. | E |
| C. | C |
| D. | B |
| Answer» B. E | |
| 2. |
The detention period of a flash mixer is _________________Figure: Flash mixer |
| A. | 2 minutes |
| B. | 30 minutes |
| C. | 1 hour |
| D. | 2 hours |
| Answer» B. 30 minutes | |
| 3. |
‘C’ in the following figure represents the ________Figure: Flash mixer |
| A. | Impeller |
| B. | Impeller shaft |
| C. | Deflecting wall |
| D. | Flash mixer wall |
| Answer» D. Flash mixer wall | |
| 4. |
The speed of impeller in a flash mixer is ___________Figure: Flash mixer |
| A. | 45rpm |
| B. | 60rpm |
| C. | 110rpm |
| D. | 200rpm |
| Answer» D. 200rpm | |
| 5. |
Which of the following is correctly paired in the following figure?Figure: Flash mixer |
| A. | C – Impeller |
| B. | D – Outlet |
| C. | F – Deflecting wall |
| D. | E – Impeller |
| Answer» E. | |
| 6. |
Which of the following is the correct expression regarding temporal mean velocity in the following figure?Figure: Flash mixer |
| A. | G = (P/μV)1/2 |
| B. | G = (P/μV) |
| C. | G = (P/μV)2 |
| D. | G = (Pμ/V)1/2 |
| Answer» B. G = (P/μV) | |
| 7. |
Which of the following goes to the flocculation tank in the following figure?Figure: Flash mixer |
| A. | B |
| B. | C |
| C. | E |
| D. | F |
| Answer» C. E | |
| 8. |
_________ is the average of velocities at a point over a definite period of time.Figure: Flash mixer |
| A. | Mean velocity |
| B. | Relative velocity |
| C. | Velocity gradient |
| D. | Temporal mean velocity |
| Answer» E. | |
| 9. |
Which of the following represents the device which is used for sludge removal in the following figure?Figure: Flash mixer |
| A. | F |
| B. | E |
| C. | D |
| D. | B |
| Answer» D. B | |
| 10. |
Which of the following represents the coagulant pipe in the following figure?Figure: Flash mixer |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 11. |
OUT_OF_THESE_WHICH_IS_NOT_USED_AS_A_CHEMICAL_COAGULANT??$ |
| A. | Alum |
| B. | Calcium chloride |
| C. | Ferric Chloride |
| D. | Poly Iron Chloride |
| Answer» E. | |
| 12. |
IRON_PRECIPITATION_OCCURS_AT_WHICH_PH??$ |
| A. | 1-3 |
| B. | 3-5 |
| C. | 5-7 |
| D. | 7-9 |
| Answer» E. | |
| 13. |
When alum is added to the waste water containing calcium ions which compound is formed as a precipitate?$ |
| A. | Al(OH)<sub>3</sub> |
| B. | Al<sub>2</sub> (SO<sub>4</sub>)<sub>3</sub> |
| C. | Ca(OH)<sub>2</sub> |
| D. | CaCO<sub>3</sub> |
| Answer» B. Al<sub>2</sub> (SO<sub>4</sub>)<sub>3</sub> | |
| 14. |
What is the one disadvantage of adding chemicals to bring about precipitation?$ |
| A. | The TSS increases |
| B. | The TDS increases |
| C. | BOD increases |
| D. | It imparts colour |
| Answer» C. BOD increases | |
| 15. |
What is the recommended surface loading rate in case of alum floc suspension? |
| A. | 30-70 m<sup>3</sup>/m<sup>2</sup>.d |
| B. | 10-30 m<sup>3</sup>/m<sup>2</sup>.d |
| C. | 70-100 m<sup>3</sup>/m<sup>2</sup>.d |
| D. | <10 m<sup>3</sup>/m<sup>2</sup>.d |
| Answer» B. 10-30 m<sup>3</sup>/m<sup>2</sup>.d | |
| 16. |
Why is Ferric ammonium sulfate generally not used as a coagulant? |
| A. | It is very expensive |
| B. | It is dependent on the Dissolved oxygen present in the waste water |
| C. | It is a very slow process |
| D. | It works only at high pH |
| Answer» C. It is a very slow process | |
| 17. |
Along with ferrous sulphate what other chemical is added in order to bring about precipitation? |
| A. | Alum |
| B. | PAC |
| C. | Lime |
| D. | Polyelectrolyte |
| Answer» D. Polyelectrolyte | |
| 18. |
Alum precipitation occurs at which pH? |
| A. | 1-3 |
| B. | 3-5 |
| C. | 5-7 |
| D. | 7-9 |
| Answer» D. 7-9 | |
| 19. |
Microflocculation is brought about by which phenomenon? |
| A. | Velocity gradient |
| B. | Differential settling |
| C. | Brownian movement |
| D. | Differential mixing |
| Answer» D. Differential mixing | |
| 20. |
What is the speed of the impeller in a flash mixer? |
| A. | 90 rpm |
| B. | 100 rpm |
| C. | 110 rpm |
| D. | 120 rpm |
| Answer» D. 120 rpm | |
| 21. |
What is the density of alum content used in water treatment? |
| A. | 9.8 lb/gal |
| B. | 10.1 lb/gal |
| C. | 11.1 lb/gal |
| D. | 9.2 lb/gal |
| Answer» D. 9.2 lb/gal | |
| 22. |
The agglomeration of destabilized particles into large particles is called _________ |
| A. | Sedimentation |
| B. | Coagulation |
| C. | Flocculation |
| D. | Disinfection |
| Answer» D. Disinfection | |
| 23. |
What is the first step in clarification? |
| A. | Sedimentation |
| B. | Coagulation |
| C. | Flocculation |
| D. | Screening |
| Answer» C. Flocculation | |
| 24. |
Clarification removes most of the turbidity. |
| A. | True |
| B. | False |
| Answer» B. False | |