Water Supply Engineering MCQ Questions and Answers in Civil Engineering

Question. If the chosen diameter of a pipe, is less than the economical diameter
(a) Cost of pipe will be less
(b) Head loss will be high
(c) Cost of pumping will be more than saving
(d) All the above

Answer : D

Question. As per IS : 1172-1963, water required per head per day for average domestic purposes, is
(a) 65 litres
(b) 85 litres
(c) 105 litres
(d) 135 litres

Answer : D

Question. For the prediction of future population of a city, the factor to be considered, is
(a) Births
(b) Deaths
(c) Migrants
(d) All the above

Answer : D

Question. The process of passing water through beds of granular materials, is called
(a) Screening
(b) Sedimentation
(c) Filtration
(d) None of these

Answer : C

Question. The specific retention is least in case of
(a) Clay
(b) Sand
(c) Silt
(d) Coarse gravel.

Answer : D

Question. If four fires break out in a city of population 40 lakhs and if each hydrant has three streams and duration of each fire is four hours, the total quantity of water required, is
(a) 1880 kilo litres
(b) 2880 kilo litres
(c) 3880 kilo litres
(d) 4880 kilo litres

Answer : B

Question. The least thickness of class B cast iron (spun) pipe, is
(a) 7.2 mm
(b) 7.9 mm
(c) 8.6 mm
(d) 10 mm

Answer : C

Question. Pick up the incorrect statement from the following. The underground sources of water, is from
(a) wells
(b) springs
(c) infiltration wells
(d) storage reservoirs

Answer : D

Question. Turbidity of raw water is a measure of
(a) Suspended solids
(b) Acidity of water
(c) B.O.D
(d) None of these

Answer : A

Question. Sunlight
(a) helps growth of bacterias
(b) impedes growth of algae
(c) increases dissolved oxygen content
(d) reduces turbidity

Answer : B

Question. In slow sland filters, the turbidity of raw water can be removed only up to
(a) 60 mg/litre
(b) 75 mg/litre
(c) 100 gm/litre
(d) 150 mg/litre

Answer : A

Question. Mathamoglobinemia or blue baby disease is caused due to
(a) Chlorides
(b) Nitrites
(c) Nitrates
(d) Sulphides

Answer : C

Question. According to IS : 1172-1963, a minimum of 135 litres of water capita per day, is required for
(a) Boarding schools
(b) Nurses home and medical quarters
(c) hostels
(d) all the above

Answer : D

Question. Specific capacity or yield of wells, is generally expressed, as
(a) m³/sec
(b) m³/hour
(c) m³/hour/m²
(d) m³/hour/m²/m

Answer : D

Question. Pick up the correct statement from the following:
(a) The water level in a still well, represents the ground water table level
(b) The difference between water table level and the water level in a well after pumping, is called depression head
(c) The surface of water table surrounding a well during pumping, forms a cone of depression
(d) All the above

Answer : D

Question. The expected discharge to be obtained from an open well sunk in coarse sand is 0.0059 cume(c) If the working depression head of the well is 3 m, the minimum diameter of the well, is
(a) 2 m
(b) 2.25 m
(c) 2.50 m
(d) 3.00 m

Answer : D

Question. The yield of a rapid gravity filter as compared to that of slow sand filter, is
(a) 10 times
(b) 15 times
(c) 20 times
(d) 30 times

Answer : D

Question. Surcharge storage zone of a reservoir, is
(a) Below dead storage
(b) Between dead storage and useful storage
(c) Above useful storage
(d) Also known as valley storage

Answer : C

Question. The R.L. of ground water table on the sides of a valley is 1505 m whereas R.L. of the stream water is 1475 m. If 60° slope consists of pervious soil between R.L. 1485 m to 1500 m, the gravity spring may be expected at the point of reduced level
(a) 1500 m
(b) 1505 m
(c) 1475 m
(d) 1485 m

Answer : D

Question. For determining the velocity of flow of underground water, the most commonly used non-empirical formula is
(a) Darcy’s formula
(b) Slichter’s formula
(c) Hazen’s formula
(d) Lacy’s formula

Answer : A

Question. Corrosion of well pipes may not be reduced by
(a) reducing the draw down and the pumping rate
(b) reducing the flow velocity
(c) using thicker pipes
(d) using screens having larger area of openings

Answer : D

Question. In distribution pipes, drain valves are provided at
(a) lower point
(b) higher point
(c) junction points
(d) any where

Answer : A

Question. By boiling water, hardness can be removed if it is due to
(a) calcium sulphate
(b) magnesium sulphate
(c) calcium nitrate
(d) calcium bicarbonate

Answer : D

3. Acidity in water is caused due to
(a) Mineral acids
(b) Free CO2
(c) Aluminium sulphate
(d) All the above

Answer : D

Question. Aeration of water is done to remove
(a) odour 
(b) colour
(c) bacterias
(d) hardness

Answer : A

Question. The maximum depth of sedimentation tanks is limited to
(a) 3 m
(b) 4 m
(c) 5 m
(d) 6 m

Answer : D

Question. Asbestos pipes are
(a) light in weight and easy to transport
(b) highly resistant to corrosion
(c) very much smooth and hydraulically efficient
(d) all the above

Answer : D

Question. In centrifugal pump installation,
(a) Pump is properly primed before starting
(b) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe
(c) The motor may burn out if it is started with empty delivery pipe and with open gate valve
(d) All the above

Answer : D

Question. To pump water from a water reservoir 3 m deep and maximum water level at 135 m, a pump is installed to lift water up to R.L. 175 m at a constant rate of 36,00,000 litres per hour. If the length of the pipe is 1506 m and f = 0.01, ignoring other minor losses and assuming the economical diameter from Lea's formula D = 1.2√Q, the water horse power of the pump is
(a) 400
(b) 450
(c) 500
(d) 600

Answer : D

Question. Average annual rainfall at any station is the average of annual rainfall over a period of
(a) 14 years
(b) 21 years
(c) 28 years
(d) 35 years

Answer : D

Question. Disinfection of drinking water, is done to remove
(a) odour
(b) bacterias
(c) turbidity
(d) colour

Answer : B

Question. Pick up the correct statement from the following:
(a) The water level in a still well, represents the ground water table level
(b) The difference between water table level and the water level in a well after pumping, is called depression head
(c) The surface of water table surrounding a well during pumping, forms a cone of depression
(d) All the above

Answer : D

Question. Pick up the correct statement from the following:
(a) Water with hardness up to 75 ppm is considered soft
(b) Water with hardness more than 200 ppm is considered hard
(c) Water needed for laundries should contain hardness less than 75 ppm
(d) All the above

Answer : D

Question. Time of concentration
(a) is the time taken, for precipitation
(b) duration of rainfall.
(c) time taken for all the ran off to reach the drain
(d) time taken for the storm water to travel from the most remote point to the drain.

Answer : D

Question. In pressure supply mains, water hammer pressure is reduced by providing
(a) Sluice valves
(b) Air valves
(c) Pressure relief valves
(d) None of these

Answer : C

Question. When the reduced level of the water source is higher than the reduced level of the consumer's place, water is generally supplied
(a) By pumping system
(b) By gravitational system
(c) Both (A) and (B)
(d) All the above

Answer : B

Question. While determining the yield of open wells by the pumping test
(a) Velocity of recharging water, increases with depression head
(b) Depression head resulting at critical velocity, is called critical depression head
(c) Working head is generally limited to ?rd of the critical depression head
(d) Maximum safe yield of an open well, is expected at critical depression head

Answer : D

Question. The factor affecting per capita demand, is
(a) size of the city
(b) climatic conditions
(c) cost of water
(d) all the above

Answer : D

Question. Surge tanks are used
(a) for storage water
(b) to increase the velocity in a pipeline
(c) as overflow valves
(d) to guard against water hammer

Answer : D

Question. The fire demand of a city may be worked out by
(a) Kuichling’s formula
(b) Freeman formula
(c) Bustan’s formula
(d) All the above

Answer : D

Question. Biochemical Oxygen Demand  B.O.D of safe drinking water must be
(a) nil
(b) 5
(c) 10
(d) 15

Answer : A