A. higher temperature
B. sunlight
C. satisfying oxygen demand
D. none of the above
Related Mcqs:
- The self cleansing velocity for all sewers in India is usually_________________?
A. less than 1.0 m/sec
B. 1.0 m/sec to 1.2 m/sec
C. 1.5 m/sec to 2.0 m/sec
D. 3.0 m/sec to 3.5 m/sec - The effect of increasing diameter of sewer on the self cleansing velocity is_____________?
A. to decrease it
B. to increase it
C. fluctuating
D. nil - Which of the following sewers is preferred for combined system of sewage ?
A. circular sewer
B. egg shaped sewer
C. rectangular sewer
D. none of the above - Which of the following unit works in anaerobic conditions ?
A. sludge digestion tank
B. sedimentation tank
C. activated sludge treatment
D. trickling filters - Which of the following methods of analysis of water distribution system is most suitable for long and narrow pipe system ?
A. circle method
B. equivalent pipe method
C. Hardy cross method
D. electrical analysis method - Which of the following compounds is widely used for algae control ?
A. sodium sulphate
B. copper sulphate
C. sodium chloride
D. calcium chloride - Which of the following chemical compounds can be used for dechlorination of water ?
A. carbon dioxide
B. bleaching powder
C. sulphur dioxide
D. chloramines - Which of the following values of pH represents a stronger acid?
A. 2
B. 5
C. 7
D. 10 - Which of the following is not a water borne disease ?
A. dysentery
B. cholera
C. typhoid
D. maleria - Which of the following causes a decrease in per capita consumption ?
A. use of metering system
B. good quality of water
C. better standard of living of the people
D. hotter climate
