Water And Wastewater Engineering Set 8 MCQs

Q1 | For determining the velocity of flow of underground water, the most commonly usednonempirical formula is

Darcy's formula

Slichter's formula

Hazen's formula

Lacy's formula

Q2 | The most commonly used chemical for de-chlorination of water, is

Sodium thiosulphate

Sodium bisulphate

Sodium sulphite

Sulphur-dioxide

Q3 | To remove very fine suspended particles from water, the method adopted is

Screening

Sedimentation

Boiling

Filtration

Q4 | Sunlight

Helps growth of bacterias

Impedes growth of algae

Increases dissolved oxygen content

Reduces turbidity

Q5 | The detention period for plain sedimentation water tanks, is usually

4 to 8 hours

8 to 16 hours

16 to 24 hours

24 to 36 hours

Q6 | Air valves are generally provided in pressure pipes of water supply

At pipe junctions (B) (C) (D)

At summits

At low points

Near service pipes

Q7 | The gaseous form of chlorine gets converted into liquid form when subjected to a pressure of

5 kg/cm2

6 kg/cm2

7 kg/cm2

10 kg/cm2

Q8 | Flow through period, in sedimentation tanks, is

Equal to detention period

More than detention period

Less than detention period

Detention period divided by displacement efficiency

Q9 | The maximum hourly consumption, is generally taken as

110%

120%

140%

150%

Q10 | Hardness of water can be removed by boiling if it is due to

Calcium bicarbonates

Calcium sulphates

Calcium chloride

Calcium nitrates

Q11 | Hardness of water is caused by

Presence of soap lather

Presence of chlorides and sulphates of sodium and potassium

Presence of bicarbonates, sulphates or chlorides of calcium and magnesium

Turbidity

Q12 | The average domestic consumption under normal conditions in an Indian city per day perperson, is

105 litres

115 litres

125 litres

135 litres

Q13 | If d is the diameter of the pipe, p is the total internal pressure, f is the permissible tensile stressand n is the effective of the joint, the thickness t of metal pipe, is

n (pd/2f)

(1/n) (pd/2f)

(1/n) (pd/3f)

(1/n) (pf/d)

Q14 | Generally, first portion of a logistic curve for the population growth of a developing city,represents the growth of

Increasing

Decreasing

Constant

All the above

Q15 | A pressure conduit carrying water beneath a stream or a canal, is known as

Sag (B) (C) (D)

Depressed pipe

Inverted syphon

All the above

Q16 | Most satisfactory formula for an estimate of fire demand Q for a city of population P inthousands for Indian conditions, is

Q = 1115 (p/5 + 20)

Q = 1640 ?? (1 - 0.01 ??)

Q = 3180 ??

None of these

Q17 | Permanent hardness of water can be removed by

Adding alum

Adding lime

Adding chlorine

Zeolite process

Q18 | The maximum depth of sedimentation tanks is limited to

2 m (B) (C) (D)

3 m

5 m

6 m

Q19 | Pick up the incorrect statement from the following. Intake of water supply should

Be nearer to the treatment plant

Receive water from purer zone of the source

Be located downstream of waste water disposal point

Remain easily accessible during floods

Q20 | The fire demand of a city may be worked out by

Kuichling's formula

Freeman formula

Under Writers formula

All the above

Q21 | The formula HL = n²V²L/R4/3 for the head loss in conduits is generally known as

Hazen-William's formula

Manning's formula

Darcy-Weisbach formula

Nikuradse formula

Q22 | The joint used for joining the plain ends of cast iron pipes, is

Flanged joint

Socket and spigot joint

Dresser coupling joint

Flexible joint

Q23 | Disinfection of water with ozone is not good because

It vanishes before water reaches the consumers

It removes the colour, taste and odour from water as bacterias

It adds taste to the water

It is more efficient than chlorine in killing bacterias

Q24 | The prescribed hardness limit of potable water ranges between

50 to 75 P.P.M.

75 to 115 P.P.M.

100 to 150 P.P.M.

150 to 200 P.P.M.

Q25 | While designing a water supply of an industrial township, industrial and commercial waterdemand of total supply, is assumed

10 % (B) (C) (D)

10 to 15 %

15 to 20 %

20 to 25 %