Presence of bacteria in potable (drinking) water causes_________________?

Related Mcqs:

1. TLV of mercury in potable (drinking) water is about ______________ ppm?

   A. 0.001
   B. 0.1
   C. 1
   D. 5

2. Presence of soluble organics in polluted water causes_________________?

   A. Undesirable plants growth
   B. Depletion of oxygen
   C. Fire hazards
   D. Explosion hazards

3. Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent___________________?

   A. Dental cavities
   B. Scale formation
   C. Water-borne disease
   D. Corrosion

4. Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?

   A. Mercury
   B. Lead
   C. Fluoride
   D. Arsenic

5. Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air’s water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes_________________?

   A. Poor visibility due to sky darkening
   B. Irritation in eyes
   C. Respiratory trouble
   D. All A., B. and C.

6. The pH value of potable water should be between____________________?

   A. 1 to 1.5
   B. 6.5 to 8
   C. 13 to 14
   D. 4 to 5

7. Maximum permissible turbidity in potable water is _____________ ppm?

   A. 1
   B. 10
   C. 250
   D. 1000

8. Presence of _____________ bacteria in water causes disease like typhoid?

   A. Aerobic
   B. Pathogenic
   C. Anaerobic
   D. Non-pathogenic

9. Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in____________________?

   A. Coagulation and flocculation of colloids
   B. Oxidation of carbonaceous matter to CO2
   C. Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter
   to the nitrite and eventually to the nitrate
   D. All A., B. and C.

10. Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of_________________?

    A. Ozone and iodine
    B. Chlorine or its compounds
    C. Ultraviolet light for irradiation of water
    D. All A., B. & C.