A. less and more
B. less and less
C. more and less
D. more and more
Related Mcqs:
- The overflow rate for plain sedimentation tanks is about__________________?
A. 500 to 750 litres/hour/ m2
B. 1000 to 1250 litres/hour/ m2
C. 1250 to 1500 litres/hour/m2
D. 1500 to 2000 litres/hour/m2 - The detention period in coagulation tanks is usually kept as_______________?
A. 1 to 2 minutes
B. 30 to 45 minutes
C. 2 to 6 hours
D. 2 to 6 days - Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about_______________?
A. 10 to 25
B. 50
C. 75
D. 100 - The detention period for oxidation ponds is usually kept as______________?
A. 4-8 hours
B. 24 hours
C. 10 to 15 days
D. 3 months - Generally the detention period for grit chambers is kept as_______________?
A. 1 minute
B. 5 minutes
C. 2-4 hours
D. 12 hours - The amount of coagulant needed for coagulation of water increases with_______________?
1) increase in turbidity of water
2) decrease in turbidity of water
3) increase in temperature of water
4) decrease in temperature of water
The correct answer is?A. (1) and (2)
B. (1)and (4)
C. (2) and (3)
D. (2) and (4) - The settling velocity of a particle in a sedimentation tank increases if______________?
A. particle size is decreased
B. the surface area of tank is increased
C. the depth of tank is decreased
D. none of the above - The chemical most commonly used to increase speed of sedimentation of sewage is_______________?
A. sulphuric acid
B. copper sulphate
C. lime
D. sodium permanganate - The settling velocity of a particle in a sedimentation tank depends on__________________?
A. depth of tank
B. surface area of tank
C. both depth and surface area of tank
D. none of the above - The settling velocity of a particle in a sedimentation tank increases if_________________?
A. particle size is decreased
B. the surface area of tank is increased
C. the depth of tank is decreased
D. none of the above
