Water Supply Engineering MCQs with Explanations

Biochemical Oxygen Demand (B.O.D.): Biochemical Oxygen Demand is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water. It is an important parameter for assessing water quality. Safe Drinking Water: For water to be considered safe for drinking, it should have very low levels of organic matter and microbial contamination. Therefore, the B.O.D. of safe drinking water should be as close to zero as possible. Explanation of Options: Option A: nil - Indicates that there is no measurable oxygen demand, meaning the water is free from organic contaminants. This is the ideal and safest level for drinking water. Option B: 5 - A B.O.D. level of 5 mg/L indicates some presence of organic matter, which is higher than acceptable for safe drinking water. Option C: 10 - A B.O.D. level of 10 mg/L is too high for safe drinking water and indicates significant organic pollution. Option D: 15 - A B.O.D. level of 15 mg/L is far too high and indicates severe contamination by organic matter. Therefore, the Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be nil .

Specific capacity , also known as the yield of wells, is a measure of the efficiency and productivity of a well. It is typically expressed as the volume of water a well can produce per unit time per unit drawdown per unit area. The appropriate units for expressing specific capacity are m 3 /hour/m 2 /m , which represents cubic meters of water per hour per square meter of well area per meter of drawdown. This unit of measurement helps in comparing the performance of different wells and in assessing their sustainability for water supply purposes.

All the above is the correct answer to “The fire demand of a city may be worked out by”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Nitrates is the correct answer to “Mathamoglobinemia or blue baby disease is caused due to”. This question is standard in competitive examination syllabi for Water Supply Engineering.

All the above is the correct answer to “Acidity in water is caused due to”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Coarse gravel. is the correct answer to “The specific retention is least in case of”. This question is standard in competitive examination syllabi for Water Supply Engineering.

time taken for the storm water to travel from the most remote point to the drain. is the correct answer to “Time of concentration”. This question is standard in competitive examination syllabi for Water Supply Engineering.

1485 m is the correct answer to “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”. This question is standard in competitive examination syllabi for Water Supply Engineering.

35 years is the correct answer to “Average annual rainfall at any station is the average of annual rainfall over a period of”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Maximum safe yield of an open well, is expected at critical depression head is the correct answer to “While determining the yield of open wells by the pumping test”. This question is standard in competitive examination syllabi for Water Supply Engineering.

all the above is the correct answer to “According to IS : 1172-1963, a minimum of 135 litres of water capita per day, is required for”. This question is standard in competitive examination syllabi for Water Supply Engineering.

2880 kilo litres is the correct answer to “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”. This question is standard in competitive examination syllabi for Water Supply Engineering.

All the above is the correct answer to “For the prediction of future population of a city, the factor to be considered, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

all the above is the correct answer to “The factor affecting per capita demand, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

calcium bicarbonate is the correct answer to “By boiling water, hardness can be removed if it is due to”. This question is standard in competitive examination syllabi for Water Supply Engineering.

60 mg/litre is the correct answer to “In slow sland filters, the turbidity of raw water can be removed only up to”. This question is standard in competitive examination syllabi for Water Supply Engineering.

By gravitational system is the correct answer to “When the reduced level of the water source is higher than the reduced level of the consumer's place, water is generally supplied”. This question is standard in competitive examination syllabi for Water Supply Engineering.

600 is the correct answer to “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$$\sqrt {\text{Q}} ,$$ the water horse power of the pump is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Filtration is the correct answer to “The process of passing water through beds of granular materials, is called”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Above useful storage is the correct answer to “Surcharge storage zone of a reservoir, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

to guard against water hammer is the correct answer to “Surge tanks are used”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Darcy’s formula is the correct answer to “For determining the velocity of flow of underground water, the most commonly used non-empirical formula is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

odour is the correct answer to “Aeration of water is done to remove”. This question is standard in competitive examination syllabi for Water Supply Engineering.

bacterias is the correct answer to “Disinfection of drinking water, is done to remove”. This question is standard in competitive examination syllabi for Water Supply Engineering.

8.6 mm is the correct answer to “The least thickness of class B cast iron (spun) pipe, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

6 m is the correct answer to “The maximum depth of sedimentation tanks is limited to”. This question is standard in competitive examination syllabi for Water Supply Engineering.

using screens having larger area of openings is the correct answer to “Corrosion of well pipes may not be reduced by”. This question is standard in competitive examination syllabi for Water Supply Engineering.

storage reservoirs is the correct answer to “Pick up the incorrect statement from the following. The underground sources of water, is from”. This question is standard in competitive examination syllabi for Water Supply Engineering.

All the above is the correct answer to “If the chosen diameter of a pipe, is less than the economical diameter”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Suspended solids is the correct answer to “Turbidity of raw water is a measure of”. This question is standard in competitive examination syllabi for Water Supply Engineering.

3.00 m is the correct answer to “The expected discharge to be obtained from an open well sunk in coarse sand is 0.0059 cumec. If the working depression head of the well is 3 m, the minimum diameter of the well, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

lower point is the correct answer to “In distribution pipes, drain valves are provided at”. This question is standard in competitive examination syllabi for Water Supply Engineering.

all the above is the correct answer to “Asbestos pipes are”. This question is standard in competitive examination syllabi for Water Supply Engineering.

135 litres is the correct answer to “As per IS : 1172-1963, water required per head per day for average domestic purposes, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.

Option "impedes growth of algae" is the correct answer for this question under Water Supply Engineering.

Pressure relief valves is the correct answer to “In pressure supply mains, water hammer pressure is reduced by providing”. This question is standard in competitive examination syllabi for Water Supply Engineering.

All the above is the correct answer to “In centrifugal pump installation,”. This question is standard in competitive examination syllabi for Water Supply Engineering.

30 times is the correct answer to “The yield of a rapid gravity filter as compared to that of slow sand filter, is”. This question is standard in competitive examination syllabi for Water Supply Engineering.