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.
| 51. |
The process of removal of excess chlorine from water is ____________ |
| A. | Plain chlorination |
| B. | Dechlorination |
| C. | Super chlorination |
| D. | Double chlorination |
| Answer» C. Super chlorination | |
| 52. |
Which of the following is termed as free available chlorine? |
| A. | Hypochlorous acid |
| B. | Hypochlorite ions |
| C. | Molecular chlorine |
| D. | Hypochlorous acid, Hypochlorite ions, Molecular chlorine |
| Answer» E. | |
| 53. |
Consider the following variables.i. Concentration of disinfectantii. Concentration of organismsiii. Temperatureiv. Time of contactDisinfection is the function of which of the following variables? |
| A. | i, ii |
| B. | i, ii, iii |
| C. | i, ii, iii, iv |
| D. | ii, iii, iv |
| Answer» D. ii, iii, iv | |
| 54. |
__________ is the application of chlorine at two or more points in the purification process. |
| A. | Plain chlorination |
| B. | Pre chlorination |
| C. | Super chlorination |
| D. | Double chlorination |
| Answer» E. | |
| 55. |
The contact time for disinfection by combined chlorine is ______________ |
| A. | 20 minutes |
| B. | 30 minutes |
| C. | 40 minutes |
| D. | 60 minutes |
| Answer» E. | |
| 56. |
Efficiency of dilution decreases rapidly when the coefficient of dilution is ____________ |
| A. | 0 |
| B. | 1 |
| C. | <1 |
| D. | >1 |
| Answer» E. | |
| 57. |
The permissible limit of free residual chlorine is ___________ |
| A. | 0.02ppm |
| B. | 0.2ppm |
| C. | 1ppm |
| D. | 2ppm |
| Answer» C. 1ppm | |
| 58. |
In which form of chlorination, chlorine applies to raw water supply as it enters the distribution system? |
| A. | Plain chlorination |
| B. | Pre chlorination |
| C. | Super chlorination |
| D. | Double chlorination |
| Answer» B. Pre chlorination | |
| 59. |
The normal dose of chlorine during post chlorination is ___________ |
| A. | 0.5-1ppm |
| B. | 0.1-0.2ppm |
| C. | 0.1-0.5ppm |
| D. | 1-2ppm |
| Answer» C. 0.1-0.5ppm | |
| 60. |
Chlorine which gets consumed in the oxidation of impurities before disinfection is ______________ |
| A. | Free chlorine |
| B. | Residual chlorine |
| C. | Chlorine demand |
| D. | Residual demand |
| Answer» D. Residual demand | |
| 61. |
Iodine is a better disinfectant to kill virus than hypoiodous acid. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» C. May be True or False | |
| 62. |
The normal dose of chlorine during pre chlorination is ___________ |
| A. | 0.5-1ppm |
| B. | 0.1-0.2ppm |
| C. | 0.1-0.5ppm |
| D. | 1-2ppm |
| Answer» D. 1-2ppm | |
| 63. |
The number of organisms destroyed is equal to the number of organisms remaining at time t = __________ |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 10 |
| Answer» B. 1 | |
| 64. |
Boiling of water is a _____ method of disinfection. |
| A. | Physical |
| B. | Chemical |
| C. | Mechanical |
| D. | Electrical |
| Answer» B. Chemical | |
| 65. |
Which type of chlorine is represented by the red line as shown in the following figure? |
| A. | Free residual chlorine |
| B. | Ammonia chlorine |
| C. | Combined residual chlorine |
| D. | Residual chloramine |
| Answer» C. Combined residual chlorine | |
| 66. |
Which type of chlorine is represented by the green line as shown in the following figure? |
| A. | Free residual chlorine |
| B. | Ammonia chlorine |
| C. | Combined residual chlorine |
| D. | Residual chloramine |
| Answer» B. Ammonia chlorine | |
| 67. |
AT_WHAT_PH,_THE_E-COLI_BACTERIA_WILL_DIE_IN_THE_WATER??$ |
| A. | 6 |
| B. | 7 |
| C. | 9 |
| D. | >9.5 |
| Answer» E. | |
| 68. |
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 | |
| 69. |
The_depth_of_water_while_using_ultra_violet_ray_treatment_for_disinfection_should_be_____$ |
| A. | 35cm |
| B. | 46cm |
| C. | 28cm |
| D. | 10cm |
| Answer» E. | |
| 70. |
Addition of KMnO4 to water imparts _____ color. |
| A. | Blue |
| B. | Red |
| C. | Pink |
| D. | White |
| Answer» D. White | |
| 71. |
What is the dose of lime required in the excess lime treatment? |
| A. | 10-20ppm |
| B. | 0-10ppm |
| C. | 5-10ppm |
| D. | 5-20ppm |
| Answer» B. 0-10ppm | |
| 72. |
Which minor method of disinfection is effective in complete sterilization of water? |
| A. | Boiling method |
| B. | Excess lime treatment |
| C. | Silver treatment |
| D. | Ultraviolet ray treatment |
| Answer» B. Excess lime treatment | |
| 73. |
The pathogenic bacteria do not last long at a pH ______ |
| A. | >11 |
| B. | <11 |
| C. | <8 |
| D. | >8 |
| Answer» B. <11 | |
| 74. |
Which of the following is a chemical method of disinfection? |
| A. | Disinfection by heat |
| B. | Disinfection by light |
| C. | Metal ions |
| D. | Metal ions, Alkalis and acids |
| Answer» E. | |
| 75. |
Sunlight is a ________ method of disinfection. |
| A. | Physical |
| B. | Chemical |
| C. | Mechanical |
| D. | Electrical |
| Answer» B. Chemical | |
| 76. |
Boiling of water is a _____ method of disinfection. |
| A. | Physical |
| B. | Chemical |
| C. | Mechanical |
| D. | Electrical |
| Answer» B. Chemical | |
| 77. |
Which of the following is wrong regarding disinfection? |
| A. | It should be readily available at reasonable cost |
| B. | Its method of application should be simple |
| C. | It should render the water toxic for its intended use |
| D. | It should act as safeguard against re-contamination |
| Answer» D. It should act as safeguard against re-contamination | |
| 78. |
Which water treatment process is done after filtration of water? |
| A. | Primary sedimentation |
| B. | Disinfection |
| C. | Secondary sedimentation |
| D. | Flocculation |
| Answer» C. Secondary sedimentation | |