Top 250+ Solved Water and Wastewater Engineering MCQ Questions Answer
Q. For a continuous flow type of sedimentation tanks
a. Width of the tank is normally kept about 6 m
b. Length of the tank is normally kept 4 to 5 times the width
c. ) Maximum horizontal flow velocity is limited to 0.3 m/minute
d. All the above
Q. The asbestos cement sewers are
a. Light in weight
b. Not structurally strong to bear large compressive stress
c. Susceptible to corrosion by sulphuric acid
d. All the above
Q. For efficient working of a sewer, it must be ensured that
a. Minimum velocity of 0.45 m/sec, is maintained at its minimum flow
b. A maximum velocity of 0.90 m/sec, is maintained at its maximum flow
c. Both (a) and (b)
d. Neither (a) nor (b)
Q. Bottom openings 15 cm × 15 cm in the standing baffle wall are provided
a. 15 cm c/c
b. 22.5 cm c/c
c. 30 cm c/c
d. 50 cm c/c
Q. For drainage pipes in buildings the test applied before putting them to use, is
a. Water test
b. Smoke test
c. Straightness test
d. All the above
Q. The pressure exerted by
a. The sewage when running full from inside, is called internal pressure
b. The internal pressure if any, causes tensile stress in the pipe material
c. Pressure sewers are designed to be safe in tension
d. All the above
Q. No treatment of the sewage is given if dilution factor is
a. Less than 150
b. Between 150 to 200
c. Between 200 to 300
d. More than 500
Q. Which of the following pumps in used to pump sewage solids with liquid sewage withoutclogging the pump is?
a. Centrifugal pump
b. Pneumatic ejector
c. Reciprocating pump
d. None of these
Q. Acid regression stage of sludge digestion at a temperature 21°C extends over a period of
a. 15 days
b. 30 days
c. ) 60 days
d. 90 days
Q. The coagulant which is generally not used for treating the sewage, is
a. Alum
b. Ferric chloride
c. Ferric sulphate
d. Chlorinated copperas
Q. The layers of vegetable wastes and night soil alternatively piled above the ground to form a mound, is called
a. A heap
b. Plateau
c. Windrow
d. None of these
Q. If the flame of a miner's safety lamp in the upper layers of the sewer forms an explosive, thesewer certainly contains
a. Hydrogen sulphide
b. Carbon dioxide
c. Methane
d. Oxygen
Q. The gas which may cause explosion in sewers, is
a. Carbondioxide
b. Methane
c. Ammonia
d. Carbon monoxide
Q. Pick up the incorrect statement from the following:
a. The process of decomposing the organic matter under controlled anaerobic conditions, is called sludge digestion
b. Sludge digestion is carried out in sludge tank
c. The gases produced in sludge digestion process, contain 75% carbon dioxide
d. The gases produced in sludge digestion process, contain 75% methane
Q. The sewer pipes
a. Carry sewage as gravity conduits
b. Are designed for generating self-cleansing velocities at different discharge
c. Should resist the wear and tear caused due to abrasion
d. All the above