A. the time taken by rainfall water to run from most distant point of water shed to the inlet of sewer
B. the time required for flow of water in sewer to the point under consideration
C. sum of (A) and (B)
D. difference of (A) and (B)
Related Mcqs:
- Generally the detention period for grit chambers is kept as_______________?
A. 1 minute
B. 5 minutes
C. 2-4 hours
D. 12 hours - The means of access for inspection and cleaning of sewer line is known as_______________?
A. inlet
B. manhole
C. drop manhole
D. catch basin - 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 - In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________?
A. 100 ppm
B. 200 ppm
C. 300 ppm
D. 400 ppm - If the time of concentration is 9 minutes, then the intensity of rainfall according to British Ministry of Health formula will be__________________?
A. 4 mm/hr
B. lOmm/hr
C. 20 mm/hr
D. 40 mm/hr - Sludge volume index is defined as the ratio of_______________?
A. percentage of sludge by volume to percentage of suspended solids by weight
B. percentage of sludge by volume to percentage of total solids by weight
C. percentage of suspended solids by weight to percentage of sludge by volume
D. percentage of total solids by weight to percentage of sludge by volume - 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 pathogens can be killed by_______________?
A. nitrification
B. chlorination
C. oxidation
D. none of the above - The disinfection efficiency of chlorine increases by_______________?
1) decreasing the time of contact
2) decreasing the temperature of water
3) increasing the temperature of water
The correct answer is ?
A. only (1)
B. both (1) and (2)
C. both (1) and (3)
D. only (3) - The per capital consumption of a locality is affected by_________________?
1) climatic conditions
2) quality of water
3) distribution pressure
The correct answer is?A. only (1)
B. both (1) and (2)
C. both (1) and (3)
D. all (1), (2) and (3)
