Q.1

Drop manholes are the manholes

  • without entry ladders
  • without manhole covers
  • with depths more than 3.5 m
  • having drains at different levels.
Q.2

Pick up the correct statement from the following :

  • Small sewers are cleaned by flushing
  • Medium sewers are cleaned by cane rodding
  • Medium sewers may be cleaned by pills
  • Large sewers are cleaned by removing the deposited materials
  • All the above.
Q.3

In normal conditions, the period for sludge digestion, is

  • 10 days
  • 20 days
  • 30 days
  • 60 days
  • 90 days.
Q.4

The underground sewers are more subjected to

  • tensile force
  • compressive force
  • bending force
  • shearing force.
Q.5

The laying of sewers is done with

  • magnetic compass
  • theodolite
  • level
  • clinometer
  • plane table.
Q.6

Cement concrete sewers are only suitable if non-scouring velocity is between

  • 2.5 to 3.0 m/sec
  • 3.0 to 4.0 m/sec
  • 3.5 to 4.5 m/sec
  • 4.5 to 5.5 m/sec.
Q.7

The layers of vegetable wastes and night soil alternatively piled above the ground to form a mound, is called

  • a heap
  • plateu
  • windrow
  • none of these.
Q.8

For sewers, inverted siphon is provided for

  • one pipe
  • two pipes
  • three pipes
  • four pipes.
Q.9

Acid regression stage of sludge digestion at a temperature 21°C extends over a period of

  • 15 days
  • 30 days
  • 60 days
  • 90 days.
Q.10

The normal value of over flow rates for plain primary sedimentation tanks, ranges between

  • 25, 000 to 35, 000 litres/sqm/day
  • 40, 000 to 50, 000 litres/sqm/day
  • 50, 000 to 60, 000 litres/sqm/day
  • 80, 000 to 100, 000 litres/sqm/day
  • none of these.
Q.11

The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known

  • house sewer
  • lateral sewer
  • branch sewer
  • sewer outfall.
Q.12

The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope

  • 1 in 5
  • 1 in 10
  • 1 in 15
  • 1 in 20
  • 1 in 25
Q.13

Pick up the correct statement from the following :

  • the sewer pipes of sizes less than 0.4 m diameter are designed as running full at maximum discharge
  • the sewer pipes of sizes greater than 0.4 m diameter are designed as running 2/3rd or 3/4th full at maximum discharge
  • the minimum design velocity of sewer pipes is taken as 0.8 m/sec
  • all the above.
Q.14

The rational formula for peak drainage discharge, was evolved by

  • Fruhling
  • Lloyd David
  • Kuichling
  • All of these.
Q.15

The grit chambers of sewage treatment plants, are generally cleaned after

  • 2 days
  • 5 days
  • 7 days
  • 12 days
  • 14 days.
Q.16

The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known

  • house sewer
  • lateral sewer
  • branch sewer
  • sewer outfall.
Q.17

If the discharge of a sewer running half is1.p.s., i = 0.and n = 0.the diameter of the sewer, is

  • 1.39 m
  • 1.49 m
  • 1.59 m
  • 1.69 m
  • 1.79 m.
Q.18

The coagulant which is generally not used for treating the sewage, is

  • alum
  • ferric chloride
  • ferric sulphate
  • chlorinated copperas.
Q.19

If the pH value of sewage is 7

  • it is acidic
  • it is alkaline
  • it is neutral
  • none of these.
Q.20

The asbestos cement sewers are

  • light in weight
  • not structurally strong to bear large compressive stress
  • susceptible to corrosion by sulphuric acid
  • All the above.
Q.21

To maintain aerobic biological activity, the moisture content of the compost mass should be about

  • 45%
  • 50%
  • 55%
  • 60%.
Q.22

Pick up the incorrect statement from the following for allowing workers to enter sewers

  • The particular manhole and one manhole on up stream and one manhole on down stream should remain open for 30 minutes
  • Proper tests for the presence of poisonous gases must be carried out
  • The men entering the manhole should be advised to smoke in the sewer
  • Warning signals should be erected
  • None of these.
Q.23

If the depletion of oxygen is found to be 5 ppm after incubating a 2.solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is

  • 50 ppm
  • 100 ppm
  • 150 ppm
  • 200 ppm
  • 250 ppm.
Q.24

The quantity of liquid waste which flows in sewers during the period of rainfall, is known

  • sanitary sewage
  • industrial waste
  • storm sewage
  • none of these.
Q.25

For a continuous flow type of sedimentation tanks

  • width of the tank is normally kept about 6 m
  • length of the tank is normally kept 4 to 5 times the width
  • maximum horizontal flow velocity is limited to 0.3 m/minute
  • capacity of the tank for 24 hours, is kept equal to maximum daily flow of sewage
  • all the above.
Q.26

The intensity of rain is expressed in

  • cm/minute
  • cm/hour
  • cm/day
  • none of these.
Q.27

The sewer pipes

  • carry sewage as gravity conduits
  • are designed for generating self-cleansing velocities at different discharge
  • should resist the wear and tear caused due to abrasion
  • all the above.
Q.28

The sewage treatment in septic tanks is due to

  • anaerobic decomposition
  • aerobic decomposition
  • parasitic decomposition
  • none of these.
Q.29

The spacing of bars for perforations in coarse screens used for the treatment of sewage, is

  • 20 mm
  • 30 mm
  • 40 mm
  • 50 mm
  • 100 mm.
Q.30

For efficient working of a sewer, it must be ensured that

  • minimum velocity of 0.45 m/sec, is maintained at its minimum flow
  • a maximum velocity of 0.90 m/sec, is maintained at its maximum flow
  • both (a) and (b)
  • neither (a) nor (b).
Q.31

Fresh sewage is generally

  • alkaline
  • acidic
  • highly decomposed
  • a source of objectionable odour.
Q.32

Bottom openingscm xcm in the standing baffle wall are provided

  • 15 cm c/c
  • 22.5 cm c/c
  • 30 cm c/c
  • 50 cm c/c.
Q.33

The pressure exerted by

  • the sewage when running full from inside, is called internal pressure
  • the internal pressure if any, causes tensile stress in the pipe material
  • pressure sewers are designed to be safe in tension
  • All the above.
Q.34

The sewer that unloads the sewage at the point of treatment is called

  • main sewer
  • outfall sewer
  • branch sewer
  • house sewer.
Q.35

Setting out the alignments of sewers may start from

  • city
  • out-fall
  • tail end
  • any point.
Q.36

The most efficient cross-section of sewers in a combined sewerage system is

  • parabolic
  • circular
  • rectangular
  • new egged.
Q.37

The temperature affects the

  • biological activity of bacterias in sewage
  • solubility of gases in sewage
  • viscosity of sewage
  • all the above.
Q.38

In areas where light rains are uniformly distributed throughout the year, the type of sewerage system to be adopted is

  • separate system
  • combined system
  • partially combined system
  • none of these.
Q.39

kg of sewage contains

  • 0.112 kg in suspension
  • 0.112 kg in solution
  • 0.225 kg in solution
  • 0.450 kg in suspension
  • both (a) and (c) of above.
Q.40

The sewage treatment units in which anaerobic decomposition of organic matter is used, are called

  • imhoff tanks
  • trickling filters
  • sludge sedimentation tanks
  • none of these.
Q.41

The normal values of over flow rates for secondary sedimentation tanks, ranges between

  • 25, 000 to 35, 000 litres/sqm/day
  • 40, 000 to 50, 000 litres/sqm/day
  • 50, 000 to 60, 000 litres/sqm/day
  • 80, 000 to 10, 000 litres/sqm/day
  • none of these.
Q.42

The sewage treatment units in which anaerobic decomposition of organic matter is used, are called

  • imhoff tanks
  • trickling filters
  • sludge sedimentation tanks
  • none of these.
Q.43

In very first stage of decomposition of the organic matter in sewage

  • nitrites are formed
  • nitrates are formed
  • carbondioxide is formed
  • ammonia is formed.
Q.44

A manhole is generally provided at each

  • bend
  • junction
  • change of gradient
  • change of sewer diameter
  • all the above.
Q.45

In a trickling filter

  • filtration process is used
  • biological action is used
  • neither (a) nor (b)
  • both (a) and (b).
Q.46

Pick up the incorrect statement from the following :

  • The mixture of water and waste products, is called sewage
  • The treated sewage effluents, are generally used for irrigating the crops
  • The process of collecting, treating and disposing off the sewage, is called sewerage
  • The old convergency system was definitely better than water carried sewerage system
  • None of these.
Q.47

Faculative bacterias survive in

  • the presence of oxygen
  • the absence of oxygen
  • both cases (a) and (b)
  • neither (a) nor (b).
Q.48

A cylindrical ejector having its height 2 m fills after everyminutes with a peak sewage discharge of 0.cumec. The diameter of the ejector chamber, is

  • 2.30 m
  • 2.40 m
  • 2.45 m
  • 2.50 m.
Q.49

Pick up the incorrect statement from the following :

  • The mixture of water and waste products, is called sewage
  • The treated sewage effluents, are generally used for irrigating the crops
  • The process of collecting, treating and disposing off the sewage, is called sewerage
  • The old convergency system was definitely better than water carried sewerage system
  • None of these.
Q.50

No treatment of the sewage is given if dilution factor is

  • less than 150
  • between 150 to 200
  • between 200 to 300
  • between 400 to 500
  • more than 500
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