### Civil Engineering - UPSC Civil Service Exam Questions MCQs Part 12

1. A pipeline of 5 cm diameter is reduced abruptly to 2.5 cm diameter at a section to enable measurement of the water flowing through it. The loss of head at the contraction is 0.5 m. Given that, in metric units, 2g = 4.43 and g = 3.132, the mean velocity in the reduced section will be

A.
0.5 m/sec
B.
1.1075 m/sec
C.
1.566 m/sec
D.
4.43 m/sec

2. A clay layer, 5 m thick undergoes 50% consolidation in 5 years when subjected to an average pressure increase of 50 kN/m2. If the clay layer were 10 m thick, in what period would it undergo 50% consolidation for the same pressure ?

A.
10 years
B.
2.5 years
C.
25 years
D.
20 years

3. Which one of the following is the most preferred wood for high quality and durable furniture ?

A.
Sandalwood
B.
Deodar wood
C.
Teakwood
D.
Shisham wood

4. For ornamental work, which type(s) of bricks is/ are preferred ?1. Silica bricks2. Silica lime bricks3. Bricks produced in autoclavesSelect the correct answer using the code given below :

A.
1 and 3 only
B.
2 and 3 only
C.
1 only
D.
2 only

5. In case of footing on the surface of shallow depth is very dense sand, which one of the following types of failure is likely to occur?

A.
Punching shear failure
B.
Local shear failure
C.
General shear failure
D.
Any of the above three

6. For one cubic metre of brick masonry, the number of modular bricks needed is

A. 400 or less
B. 400 to 450
C. 500 to 550
D. 600 to 650

7. To produce low heat cements, it is necessary to reduce the compound

A. C3S
B. C2S
C. C3A
D. C4AF

8. The probability that the load on a scaffolding will exceed the design load of 3 tonnes is 0.15. At the same time, the probability that the strength of the scaffolding will be more than 3 tonnes is 0.85. The probability that the scaffolding will fail is

A. 0.2775
B. 0.1275
C. 0.0225
D. 0.0020

9. The dry density of a soil is 1.5 g/cc. If the saturation water content were 50%, then its saturated density and submerged density would, respectively, be

A. 1.5 g/cc and 1.0 g/cc
B. 2.0 g/cc and 1.0 g/cc
C. 2.25 g/cc and 1.25 g/cc
D. 2.0 g/cc and 1.50 g/cc

10. Consider the following soil parameters and conditions :1. Drainage conditions2. Thickness of layer3. Initial void ratio4. Over-burden pressureThe magnitude of settlement is influenced by,

A. 1, 2 and 3
B. 2, 3 and 4
C. 1, 3 and 4
D. 1, 3 and 4

11. A concentrated load acting on the surface of a soil produces a stress of 19.1 kPa at a depth of 1 m below it. Using Boussinesq's expression, the stress at 2 m depth is

A. 9.55 kPa
B. 6.37 kPa
C. 4.775 kPa
D. 4.37 kPa

12. Consider the following statements : Seasoning of timber results is 1. increased strength 2. increased durability.3. reduced resilience.Of these statements :

A. 1, 2 and 3 are correct
B. 1 and 3 are correct
C. 1 and 2 are correct
D. 2 and 3 are correct

13. Gypsum is added to Portland cement during its manufacture so that it may

A. accelerate the setting time
B. retard the setting time
C. decrease the burning temperature
D. facilitate grinding

14. If the velocity potential φ = 4 xy, what are the x and y components of velocity at the point(1, 4) ?

A. u = - 16, v = - 4
B. u = - 4, v = - 16
C. u = 16, v = - 4
D. u = 16, v = 16

15. Unit cost of any item of work can be found by using

A. specifications
B. value analysis
C. economic analysis
D. rate analysis

16. Which one of the following different types of submerged soils is susceptible to liquefaction under earthquake shocks ?

A. Dense sand
B. Soft clay
C. Loose silt
D. Fissured clay

17. In the given figure, σ1 and the σ2 and maximum and minimum principal stresses. In order that the resultant stress on the plane AB is the value of θ should be

A. 30°
B. 45°
C. 60°
D. 75°

18. Eutrophication of water bodies is caused by the

A. discharge of toxic substances
B. excessive discharge of nutrients
C. excessive discharge of suspended solids
D. excessive discharge of chlorides

19. For laminar flow through a circular tube, the average velocity at a section is

A. the same as that at the centre of tube
B. two-thirds the velocity at the centre of the tube
C. half the velocity at the centre of the tube
D. dependent on the pressure at the section

20. In the figure shows, the effective pressure at C is given by (symbols have the usual meanings)

A. (h + z) yw
B. zyw
C. zySub
D. hyw + zysat

21. Consider the following assumptions :1. Failure occurs on a plane surface.2. Wall is smooth but not necessarily vertical.3. Failure wedge is a rigid body.Coulomb's theory of earth pressure is based on assumptions

A. 1, 2 and 3
B. 1 and 3
C. 1 and 2
D. 2 and 3

22. A 2-metre diameter water pipe is required to withstand a 200 meter head of water. Assuming the limiting tensile stress for the pipe material to be 200 kg/cm2, the minimum thickness of the material of the pipe to be used will have to be

A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm

23. In the preliminary treatment of wastewater, skimming tanks are often included in the treatment scheme. Various features of skimming tanks are that these :1. can remove general floating matter.2. can remove oily and greasy matter.3. have detention time of 30 min.4. employ compressed air blown through diffusers.Which of these statements are correct ?

A. 1 and 3
B. 2 and 4
C. 2 and 3
D. 1 and 2

24. Consider the following statements :1. A dummy activity is artificially introduced in a network when necessary.2. A dummy activity consumes some time.3. A dummy activity is represented by a dotted arrow.4. A dummy activity must necessarily be introduced in every network. Which of the above statements are correct ?

A. 1, 2 and 3
B. 1 and 3
C. 2, 3 and 4
D. 1 and 2

25. Consider the following stages in the manufacturing of bricks :1. Weathering2. Moulding3. TemperingThe correct sequence of these stages in the manufacturing of the bricks, is

A. 1, 2, 3
B. 2, 3, 1
C. 1, 3, 2
D. 3, 2, 1

26. What is the predominating coagulation mechanism for raw water having high turbidity and high alkalinity?

A. Ionic layer compression
C. Sweep coagulation
D. Inter particle bridging

27. The momentum correction factor (β) is used to account for

A. change in the direction of flow
B. change in total energy
C. change in mass rate of flow
D. non-uniform distribution of vel-ocities

28. Where is d'Alembert's principle employed ?

A. In the design of long columns
B. To determine stresses induced in thick cylinders
C. To reduce a problem of kinetics to an equivalent problem of statics
D. In the analysis of many geotechnical problems

29. The hoop stress in a dome subjected to uniformly distributed load

A. is always compressive
B. is tensile at sections whose radius vectors are at angles less than 51°51' with the vertical
C. is tensile at sections whose radius vectors are at angles greater than 51°51' with the vertical
D. is always tensile

30. A commonly used handpump is the

A. centrifugal pump
B. reciprocating pump
C. rotary pump
D. axial flow pump

31. What is the ratio of the forces in the members AB, BE and AE of the pin-joined truss shown in the figure?

A. 5 : 4 : 3
B. 4 : 3 : 5
C.
D. None of the above

32. A sewer, 1000 mm in diameter is laid at a slope to obtain a velocity of 0.8 m/s when running full. Assuming Manning's n as constant, what is the velocity in this sewer if it is running half full.

A. 0.2 m/s
B. 0.4 m/s
C. 0.6 m/s
D. 0.8 m/s

33. For the network shown in the above figure (the number on each arrow denotes the time duration of activity in days), the earliest star time, in days for activity 5-6 is

A. 8
B. 7
C. 9
D. 11

34. A clay layer 5 m thick in field takes 300 days to attain 50% consolidation with condition of double drainage. If the same clay layer is underlain by hard rock then the time taken to attain 50% consolidation will be

A. 300 days
B. 600 days
C. 900 days
D. 1200 days

35. Two forces P = 6 N and Q = 10 N act on a particle and their lines of action are inclined to each other at an angle of 60°. What is the magnitude of the third force R which will keep the particle in equilibrium ?

A. 13.30 N
B. 13.89 N
C. 14.00 N
D. 14.02 N

36. The three-hinged arch shown in the given figure will have value of H as

A. 20 kN
B. 30 kN
C. 40 kN
D. 50 kN

37. What is 5 days 20°C BOD equal to ?

A. 3 days 27°C BOD
B. 4 days 30°C BOD
C. 6 days 32°C BOD
D. 7 days 35°C BOD

38. Consider the following statements :In solid waste management1. density separation of solid wastes can be accomplished by air classifiers.2. iron recovery from solid wastes can be done by magnetic separators.3. aluminium separation from solid wastes can be accomplished by eddy current separators. Which of the statements given above are correct ?

A. 1 and 2
B. 2 and 3
C. 1 and 3
D. 1, 2 and 3

39. Consider the following statements : 1. Book value is the unamortized cost of the asset as it still appears on the accounting books of the business.2. Termination of economic life implies disposal of the equipment.Which of the statements given above is/are correct ?

A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 nor 2

40. A person of height 1.65 m standing on a cliff of height 20 m above the water level on sea-shore can sight a ship at a distance of about

A. 10 km
B. 18 km
C. 30 km
D. 40 km

41. Which of the following characteristic features may be used while plotting a contour plan ?1. Two contour lines having the same elevation cannot unite the continue as one line.2. Contour lines closed together indicate a gentle slope.3. Contour lines cross a valley line at right angles.Select the correct answer using the codes given below:

A. 1, 2 and 3
B. 1 and 2
C. 2 and 3
D. 1 and 3

42. The radial moment at the boundary of a simply supported circular slab of radius R, subjected to a uniformly distributed load of w will be

A. wR2/8
B. wR2/12
C. 3wR2/16
D. zero

43. Soundness test of cement is done to determine its

A. durability in sea water
B. free-lime content
C. iron oxide content
D. alumina content

44. For a non-concurrent force system to be in equilibrium

A. closure of the force polygon alone is sufficient
B. closure of the funicular polygon alone is sufficient
C. both force and funicular polygon must close
D. the conditions mentioned at (a), (b) and (c) are not relevant

45. The displacement method is also referred to as which one of the following ?

A. Minimum strain energy method
B. Maxwell-Mohor method
C. Consistent deformation method
D. Slope-deflection method

46. If the CBR value obtained at 5 mm penetration is higher than that at 2.5 mm, then the test is repeated for checking ; and if the check test reveals a similar trend, then the CBR value is to be reported as the

A. Mean of the values for 5 mm and 2.5 mm penetrations
B. Higher value minus the lower value
C. Lower value corresponding to 2.5 mm penetration
D. Higher value obtained at 5 mm penetration

47. If a descending gradient of 1 in 25 meets an ascending gradient of 1 in 40, then the length of valley curve required for a headlight sight distance of 100 m will be

A. 30 m
B. 130 m
C. 310 m
D. 630 m

48. In rock masses reduction in strength occurs due to the presence of relatively large quantities of

A. silica
B. iron oxides
C. orthoclase
D. hornblende

49. What is the zone where fish life might tend to progressively dwindle when waste water, is discharged into a river, called ?

B. zone of active decomporsition
C. zone of mixing
D. zone of recovery

50. Which one of the following states of field compaction of sand deposit truly represents the corrected standard penetration test value : N (corrected) = 27 ?

A. Loose
B. Medium dense
C. Dense
D. Very dense