WBPSC AE 1998 (Calcutta Municipal Corporation) question paper with answers

Q1.Estimate of water supply project depend upon the rate of per capita consumption and probable population estimated at the end of the design period of

1. 5 to 10 years
2. 10 to 15 years
3. 5 to 20 years
4. 20 to 30 years

Q2.In case of potabel water the permissible upper limit of chloride content is

1. 250 P.P.M
2. 300 P.P.M
3. 350 P.P.M
4. 100 P.P.M

Q3.The velocity of water in water mains of 40 cm diameter is usually kept

1. above 5m/sec
2. above 18m/sec
3. above 1.8m/sec
4. below 0.5 m/sec

Q4.For determining the velocity of flow of underground water, the most commonly used non-emperical formula is

1. Darcy's formula
2. Slichter's formula
3. Hazen's formula
4. Lacy's formula

Q5.According to kuichling's formula the fire demand 'Q' in litres per minute and population 'p' in thousands is related by the equation-

1. Q=3182P
2. Q=5663√p
3. Q=3182√p
4. Q=4637√p(1-0.01√p)

Q6.Which of the following spring can be expected to provide continuous flow of water?

1. Artesian springs
2. Gravity springs
3. Surface springs
4. All of the above

Q7.For insignificant effect on the water table, the tubewells should not be spaced as one in

1. 0.5 sq.km
2. 1.0 sq.km
3. 1.5 sq.km
4. 2.0 sq.km

Q8.Shorouding is provided in case of

1. Cavity type wells
2. Slotted type wells
3. Filter type wells
4. strainer type wells

Q9.The area of a drainage bas in whose axial length is 100 km. may be taken as 3000 sq. km. The form factor of the basin will be

1. 0.20
2. 0.30
3. 0.25
4. 0.40

Q10.Maximum permissible colour for domestic supply based on cobalt scale is

1. 5 P.P.M
2. 10 P.P.M
3. 15 P.P.M
4. 20 P.P.M

Q11.The dilution ration at which the odour is handly deterct able is generally called threshould number and for public supplies it should never exceed.

1. 3
2. 5
3. 7
4. 10

Q12.Which is the most injurious metal present in water so fat as human consumption is concerned?

1. Zinc
2. Copper
3. Iron
4. Lead

Q13.The nitrate concentration in domestic supply is genetally limited to

1. 15 P.P.M
2. 30 P.P.M
3. 45 P.P.M
4. 50 P.P.M

Q14.Bacteria which use carbon di-oxide as a source of carbon are known as

1. Autotropic
2. Heterotropic
3. Aerobic
4. Anaarobic

Q15.If waste water has pH value of 6.5 it means that

1. it is acidic
2. it is alkaline
3. it is caustic
4. none of the above

Q16.In sewer treatment plants, the bulkey, floation and suspended matter is removed by

1. oxidation
2. burning
3. screening
4. churring

Q17.B.O.D of secondary effluent from ans activated sludge plant normally will be in the range of

1. less than 30 mg/litre
2. 35 to 50 mg/litre
3. 75 to 100 mg/litre
4. 100 to 125 mg/litre

Q18.In the very first stage decompostion of organic matter in sewage.

1. Hydrogen sulphide is formed
2. Carbon di-oxide is formed
3. Ammonia is formed
4. Nitrates are formed

Q19.In the design and operation of an oxidation pond which of these factors is important?

1. surface area
2. depth and shape
3. inlets and outlets
4. all of these

Q20.The spacing of steel bars in coarse screens used for treatment if sewage is

1. 100 mm
2. 50 mm
3. 40 mm
4. 20 mm

Q21.Before discharging the foul sewage into rivers it is treated by

1. screening
2. oxidation
3. sludge digestions
4. all of the above

Q22.If the depth of partial flow a sewer of diameter 2m. in 50 cm. its welled perimeter will be

1. (2/3)π
2. (2π)/2
3. 2π
4. (5π)/3

Q23.The U.C (Uniformity coefficient) D60/D10 for best fitter media sand should be

1. 4
2. 3
3. 2
4. 5

Q24.As a result of sludge digestion a combustible gas is generated. The generated gas is

1. hydrogen
2. marsh gas
3. ammonia
4. hydrogen sulphide

Q25.Which treatment unit would be affected most by the presence of dissolved diary waste?

1. grit removal
2. raw sludge pump
3. triokling filter
4. secondary digesters

Q26.Sedimentation and floration process is used for removal of

1. grit and sand
2. suspended solid
3. pathogenic organism
4. ammonia

Q27.The rate of accumulation of sludge per person per year is usually taken as

1. 10 litres
2. 20 litres
3. 30 litres
4. 50 litres

Q28.The sewer which resists sulphide corrosion is

1. brick sewer
2. cast iron sewer
3. R.C.C. sewer
4. lead sewer

Q29.In rapid sand filters the ratio of length and diameter of leteral should not be greater than

1. 10
2. 15
3. 20
4. 25

Q30.During preliminary treatment of a sewage

1. oil and grease are removed from skimming tanks
2. floating materials are removed by screening
3. grit and sand are removed by grit chambers
4. all the above

Q31.The first stage of natural process of sludge digestion is

1. oxidation
2. acid feermentation
3. alkaline fermantaion
4. acid regression

Q32.For water supply to residences, the service are provided by

1. P.V.C. pipes
2. lead
3. galvanised iron pipes
4. cast iron pipes

Q33.The maximum pressure to which cast iron pipes may be subjected to is

1. 3 kg/cm²
2. 5 kg/cm²
3. 7 kg/cm²
4. 10 kg/cm²

Q34.The four major water supply distribution systems are

1. dead end, tres, grid iron and reticulation
2. dead end, tres grid iron and circular
3. tree grid iron ring and radial
4. tree, reticulation circular and ring

Q35.The value closure is said to be gradual if the time to close the value is (T = time of closure, L = length of pipe, C is the velocity of pressure wave)

1. T=2D/C
2. T=2L/C
3. T<4L/C
4. T<4L/C

Q36.Head lost due to friction in a pipe of diameter 30 m and length 50 metre through which water is flowing at a velocity 3m/sec is

1. 1.9580 m
2. 0.7828 m
3. 0.1162 m
4. 1.3526 m

Q37.The type of joint generally used in cast iron pipe

1. Flanged joint
2. Socket and spigot joint
3. Dresser coupling joint
4. all the above

Q38.Maximum permissible contamination due to mercury in drinking water is

1. 20 mg/litre
2. 0.2 mg/litre
3. 2.002 mg/litre
4. 200 mg/litre

Q39.Which of the following can be used disinfection of swinming pools?

1. chlorine
2. bromine
3. ultra violet rays
4. any of these

Q40.Objectionable tastes and odours can be removed from water by

1. aeration
2. coagulation
3. application of activaed carbon
4. any of the above

Q41.Smaller pollutants that can be seen in air are of size not less than

1. 0.1 um
2. 1.0 um
3. 10.0 um
4. 100.0 um

Q42.Which of the following compounds in air can harm plants?

1. hydrogen fluoride
2. sulphur di oxide
3. ozone
4. smog

Q43.The depth of the water table at a place is 50m. below the ground level. To lift water from a deep tubewell in this location, the pump to be installed is

1. centrifugal pump
2. reciprocating pump
3. deep well turbine pump
4. none of these

Q44.The efficiency of a pumping set is generally assumed to be

1. 55% to 60%
2. 65% to 70%
3. 75% to 80%
4. 85% to 90%

Q45.Pumps used for sewage disposel are

1. recipocating pumps
2. vane pumps
3. mud pumps
4. centrifugal pumps

Q46.Impeller for sewage pumps is

1. shrouded impeller
2. open impeller
3. ring impeller
4. none of the above

Q47.A valve provided immediately above the pump to reduce back surge and water hammer is called

1. sluice valve
2. spring valve
3. spindle valve
4. reflex valve

Q48.A uniform rate of pumping is required in

1. gravity system
2. balanced system
3. pumping and storage system
4. all of the above

Q49.When the recirculation ratio of trickling filter for sewage treamtment is R, then the hydraulic recirulation factor is

1. (1-R)/(1+R)
2. (1+R)
3. (1-R)
4. (1+R)/(1-R)

Q50.In rapid sand filter the bacterial impurities of water can be removed up to

1. 90 per cent
2. 70 per cent
3. 50 per cent
4. 30 per cent

Q51.The gradient required to generate self-cleaning velocity case 150 mm. diameter sewer is

1. 1 in 300
2. 1 in 200
3. 1 in 150
4. 1 in 100

Q52.Non-secouring vekocity in case of cement concrete sewer is generally

1. 1.5 to 2.2 m/s
2. 2.5 to 3.0 m/s
3. 3.5 to 4.5 m/s
4. 4.5 to 5.5 m/s

Q53.The gasses given out of a septic tank are

1. CO2, H2S, CH4
2. CH4, O2, H2S
3. CO2, NH3, CO
4. CO, CO2, N2

Q54.The most widely used pump for lifting sewage is

1. reciprocating pump
2. centrifugal pump
3. air pressure pump
4. none of the above

Q55.Which of the following space needs maxium number of air changes per hour?

1. Assembly hall
2. class rooms
3. Bed rooms
4. restaurants

Q56.The commonly used mathematical model relating the B.O.D. Exertion and reacration to dissolved oxyten deficit in a stream was first developed by

1. Hazen and camp
2. Eckenfelder and 'o' conor
3. strecter and phelps
4. none of the above

Q57.Thermal invesion refers to.

1. Hot ocean current
2. Highly stable atmosphetic condition
3. Graduate rise in global temperature
4. Hot upper atmopspheric layer

Q58.Jacobs Hochhelser method is used for determination of

1. CO
2. SO2
3. NO2
4. O3

Q59.The discharge through open channel with hydraulic mean depth as 0.6 metre and bed slope 1 in 2000 and value of N in Manneg's formula as 0.0119 is (Assume channel to be rectangular and area of flow to be equal to 3.0 sq. meter.)

1. 3.5 m³/second
2. 4.0 m³/second
3. 4.2 m³/second
4. 4.7 m³/second

Q60.A rectangular channel has a bed width of 4.0 metre and bed slope 1 in 1300. The value of chezy's constant is 50. Then the maximum discharge through the channel from economic point of view will be

1. 9.268 m³/second
2. 10.650 m³/second
3. 10.328 m³/second
4. 8.750 m³/second

Q61.The maximum velocity through a circular canal takes place when the depth of flow is equal to

1. 0.95 times the diameter
2. 0.50 times the diameter
3. 0.31 times the diameter
4. 0.30 times the diameter

Q62.In a concrete lined canal the permissible velocity of water is

1. 3 metre/second
2. 2.5 metre/second
3. 2.0 metre/second
4. 1.8 metre/second

Q63.Pick up the indeterminate structure from the figures given below: [four portal- frame sketches (a)-(d): (a) a single-bay rigid frame with fixed base and a vertical point load at joint N; (b) a single-bay frame with a horizontal point load and an internal roller/hinge marked O; (c) a similar frame with a horizontal load L and hinge marked O; (d) a frame with an explicit hinge marked at joint N ("Hinge N") and a support marked L]

1. (i)
2. (ii)
3. (iii)
4. (iv)

Q64.The ratio of maximum deflection of a simply supporter beam with a central load W and of a cantilever of sam length and with a load w at free end is

1. 1/2
2. 1/10
3. 1/16
4. 1/12

Q65.[Refers to a truss figure PQR (top chord), with members to base points E, J, L, supported at E and L; EJ is a diagonal/vertical member] The force in member EJ of the following figure is

1. 5T tension
2. 4T tension
3. 4T compression
4. 5T compression

Q66.A three hinged arch of span 2l and rise h is hinged at the crown. A concentrated load P is acting at distance 'a' from the left hand support. Both supports are at same level. The vertical reaction at support will be

1. P/a
2. P
3. Pa
4. Pa²/2

Q67.[Refers to a frame figure: a triangular truss-like frame PQ at top with two vertical legs to fixed supports, with a tie member] The degree of indetermination the frame shown below is

1. Zero
2. 1
3. 2
4. 3

Q68.A cantilever beam of uniform cross-section is proped at the free end. The length of the beam is L. A total load W is acting on the beam in uniformly distributed manmer over the entire span. The support at free end is not allowed to settle. In that case the reaction at support will be

1. (1/2)W
2. (3/4)W
3. (3/16)W
4. (3/8)W

Q69.A single angle member in tension is connected by one leg only. If the area of the connecting and outstanding leg are reaspectively 'a' and 'b' then the net effective area of the angle is equal to

1. a - b/(1+0.35(b/a))
2. a + b/(1+0.2(b/a))
3. a + b/(1+0.35(b/a))
4. a + a/(1+0.35(b/a))

Q70.The effective length of a cloumn effectively held in position and restrained in directions at both ends, is equal to

1. 0.67 L
2. 0.85 L
3. 1.00 L
4. 1.50 L

Q71.If d is the gross diameter of rivet and p is the pitch of rivets the efficiency riveted joint is given be

1. (p+d)/d
2. p/(p-d)
3. (p-d)/p
4. d/(p-d)

Q72.The type of weld used for joining two surfaces approximately at right angle to each other is known as

1. U groove weld
2. Double V groove weld
3. Square butt weld
4. Fillet weld

Q73.The greatest permissible diamension of the web in panel of a plate girder is restricted to (Where t is the thickness of the web.)

1. 230 t
2. 260 t
3. 270 t
4. 25 t

Q74.A reinforced concreate beam of 25 cm. width and 50 cm. effectie depth as a clear span of 6 metres and carries a U.D.L. of 3000 kg/m. inclusive of its self weight. If the olever arm constant of the section is 0.865 maximum intensity of shear stress is

1. 8.3 kg/cm²
2. 7.6 kg/cm²
3. 10.0 kg/cm²
4. 11.4 kg/cm²

Q75.In a rectangular column with width as 'b' is eccentrically loaded with an eccentricity of 'e'. If there is no tension in the section the value of 'e' is less than

1. 1/2
2. b/3
3. b/4
4. b/6

Q76.The maximum permissible value of ratio of span to depth of a two-way simply supported R.C.C. slab is

1. 20
2. 30
3. 35
4. 40

Q77.In case of R.C.C. water tank the reinforcement bars provided in domes surrounding an opening an are called

1. Meredionalbars
2. Anchor bars
3. Trimming bars
4. distributor bars

Q78.In a plane concrete foundation, where the footing projects on either side of the wall by 'a' centimeter and if the upward pressure from the foundation is P kg/cm² the depth of foundation 'd' is given by

1. d = 0.00775a√p
2. d = 0.0775a√p
3. d = 7.75a√p
4. d = 0.000775a√p

Q79.When column of framed structure building is situated near the edge of the property line and it is not possible to extend footing on one side of the column, then the foundation is generally designed for

1. Strap footing
2. Strip footing
3. Combined footing
4. any of the above

Q80.In design of a concreate mix by Fineness modulus method the value of F.M. of coarse aggregated is 7.3, the value of fine aggregare is 2.8 and value of F.M. of combined aggregates is 6.4. The percentage of fine aggregate to combined aggregate is

1. 25
2. 50
3. 75
4. 65

Q81.An aggregate is said to be flaky; if its least dimension is less than

1. 3/4 of mean dimension
2. 3/5 of mean dimension
3. 2/4 of mean dimension
4. 5/8 of mean dimension

Q82.The impurity if mixing water which affects the setting time and strength of concrete is

1. Calcium chloride
2. Sodium carbonates and bicarbonates
3. Sodium chloride
4. Sodium sulphate

Q83.As per I.S. specification the spacing of stirrups in a R.C.C. beam shall not exceed a distance equal to

1. Effective depth of the beam
2. Width of the beam
3. Total depth of the beam
4. Lever arm of the resisting moment

Q84.For foundation on clayey soil, the maximum differential settlement is limited

1. 20 mm
2. 30 mm
3. 40 mm
4. 50 mm

Q85.The foundation on weaker soil may be done by

1. Grillage footings
2. Column footings
3. Raft foundation
4. any of the above

Q86.For heavy structure on sandy soil, the type of foundation generally provided is

1. Strap footing
2. Pier footing
3. Rafe footing
4. Combined footing

Q87.A soil sample has a porisity of 375%. The void ratio of the sample is

1. 0.4
2. 0.5
3. 0.6
4. 0.7

Q88.According to Lacy's theory scour depth R of a river in flood is given by the equation.

1. R = 0.47(Q/f)
2. R = 0.47(Q/f)^(1/3)
3. R = 0.47(Q/f)^(1/2)
4. R = 0.47(Q/f)^(1/4)

Q89.As per Rankine's formula the passive earth pressure at a depth 8 m. in dry cohesionles and with angle a intergal friction of 38 and unit weight of dry sand as 200 kg/m³

1. 672 (1/m²)
2. 650.0 (1/m²)
3. 612.2 (1/m²)
4. 600.0 (1/m²) take value of sin 38° as 0.6157

Q90.Generally the specific gravity of aggregates used in road construction is

1. 1.8
2. 2.1
3. 2.7
4. 3.5

Q91.The best compromise between the increase of length of a highway and reduction in its load carrying capacity is the rulling gradient

1. 1 to 10
2. 1 in 15
3. 1 in 20
4. 1 in 30

Q92.Water absorption values of aggregates used in surfacing work of raod construction are in range of

1. 0.1% to 2.0%
2. 2.0% to 2.5%
3. 2.5% to 3.0%
4. 3.5% to 1.0%

Q93.Minimum value of flash point of bitumen based of I.S. Specification is

1. 150°C
2. 165°C
3. 175°C
4. 200°C

Q94.A pavement is to be constructed on a subgrade soil of 15% CBR. Wheel load for medium traffic expected to use the pavement is 4082 kg. Assuming tyre pressure of 9 kg/sq.mm. and using U.S. crops of engineers method the pavement comes to

1. 20 cm
2. 18 cm
3. 25 cm
4. 22 cm

Q95.The thickness of flexible pravement with wheel lead of 4080 kg. subgrade support at 2180 kg. and ase course constant as 86 comes to (as per meledo Formula)

1. 40 cm
2. 30 cm
3. 24 cm
4. 12 cm The value of log10(1.8716) equal to 0.2722

Q96.A road has regid pavement of concrete slab of 20 cm. The other relevant date are (i) wheel load = 4080 kg. (ii) relative stiffness = 91.4 cm. (iii) equivalent radius of resisting section = 18.8 cm. Using westergard equation the stress at edge with above data is

1. 20.18 kg/cm²
2. 18.12 kg/cm²
3. 16.00 kg/cm²
4. 14.56 kg/cm²

Q97.According to Goldbeck's formula the stress due to corner load in kg/cm² is given by

1. h³/3p
2. 3p/h³
3. 3p/h²
4. h/3p