Top 250+ Solved Water and Wastewater Engineering MCQ Questions Answer
Q. The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 mper sec. The detention period recommended for the tank, is
a. 30 minutes
b. 1 hour
c. 1 hour and 30 minutes
d. 2 hours
Q. To prevent settling down of sewage both at the bottom and on the sides of a large sewer,selfcleaning velocity recommended for Indian conditions, is
a. 0.50 m/sec
b. 0.60 m/sec
c. 0.70 m/sec
d. 0.75 m/sec
Q. Assertion (A): The determination of pH value of sewerage is important. Reason (R): The efficiency of certain treatment methods depends upon the availability of pH value.
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not a correct explanation of A
c. A is true but R is false
d. A is false but R is true
Q. The normal values of over flow rates for sedimentation tanks using coagulant, ranges between
a. 25,000 to 35,000 litres/sqm/day
b. 40,000 to 50,000 litres/sqm/day
c. 50,000 to 60,000 litres/sqm/day
d. 80,000 to 100,000 litres/sqm/day
Q. During preliminary treatment of a sewage
a. Oil and grease are removed from skimming tanks
b. Floating materials are removed by screening
c. Girt and sand are removed by girt chambers
d. All the above
Q. Dry weather flow is:
a. Average daily rate of flow
b. Average monthly rate of flow
c. Average annual rate of flow
d. Water supply allowance per capita
Q. If the flame of a miner's safety lamp in a manhole extinguishes within 5 minutes, the sewercertainly contains
a. Hydrogen sulphide
b. Carbon dioxide
c. Methane
d. Oxygen
Q. Hydraulic mean radius is
a. Mean radius of sewer
b. Difference in heads between two points in circular pipes
c. Mean of radii in a pipe line of varying cross-sections
d. Cross-sectional area/wetted perimeter
Q. Normal values of overflow rate for plain sedimentation tanks in litres/hr/m2, generally range between
a. 100 to 250
b. 250 to 500
c. 500 to 750
d. 750 to 1000
Q. Most commonly used pump for lifting water in water supply mains, is
a. Axial flow pump
b. Reciprocating pump
c. Rotary type pump
d. Centrifugal pumps
Q. The fire demand for a city of 50,000 populations, according to Godrich formula, is
a. 40 mld
b. 42 mld
c. 44 mld
d. 48 mld
Q. If V is total consumption of water in litres for a population of N individuals, per capitaconsumption or water allowance for the water supply Q, is given by
a. Q = V/12N
b. Q = V/24N
c. Q = V/265N
d. None of these
Q. For controlling algae, the most commonly used chemical, is
a. Copper sulphate
b. Alum
c. Lime
d. Bleaching powder
Q. The storage capacity of a reservoir may be divided into three zones. The lowest zone is
a. Dead storage
b. Useful storage
c. Surcharge storage
d. None of these