A. 2 to 3 mm
B. 3 to 5 mm
C. 5 to 8 mm
D. 8 to 10 mm
✅ The correct answer is option A.
Civil Engineering Mcqs MCQs
Aerobic activity is maximum_______________?
A. In freshly produced sewage
B. At sewer pipes
C. In sewer treatment plants
D. None of these
✅ The correct answer is option A.
Chlorination of water is done for the removal of____________________?
A. Bacterias
B. Suspended solids
C. Sediments
D. Hardness
✅ The correct answer is option A.
Imhoff cone is used to determine_____________________?
A. Settleable solids
B. Suspended solids
C. Dissolved solids
D. None of these
✅ The correct answer is option A.
Dynamic viscosity of most of the gases with rise in temperature___________________?
A. increases
B. decreases
C. remains unaffected
D. unpredictable
✅ The correct answer is option A.
The small sewers are cleaned by____________________?
A. Flushing
B. Cane rodding
C. Wooden pills
D. None of these
✅ The correct answer is option A.
A well oxidized sewage contains nitrogen mainly as___________________?
A. Nitrates
B. Nitrites
C. Free ammonia
D. None of these
✅ The correct answer is option A.
For pipes, laminar flow occurs when Roynolds number is__________________?
A. less than 2000
B. between 2000 and 4000
C. more than 4000
D. less than 4000
✅ The correct answer is option A.
Skimming tanks are__________________?
A. Used to remove the grease and oil
B. Those from which sludge is skimmed out
C. Tanks provided with self- cleansing screens
D. Improved version of grit chambers
✅ The correct answer is option A.
The first stage of neutral process of sludge digestion, is__________________?
A. Acid fermentation
B. Acid regressio
C. Alkaline fermentation
D. None of these
✅ The correct answer is option A.