### Civil Engineering - UPSC Civil Service Exam Questions MCQs Part 25

1. If an element is subjected to pure shearing stress τxy then the maximum principal stress is equal to

A.
2τxy
B.
τxy/2
C.
τxy
D.
1 - (τxy)2

2. The wall friction of the retaining wall:

A.
decreases active earth pressure but increases passive earth pressure
B.
decreases passive earth pressure but increases active earth pressure
C.
decreases both active and passive earth pressures
D.
increases both active and passive earth pressures

3. Consider the following statements :The salient features of a bar chart over network are that :1. It is simple to draw and easy to understand.2. It is unable to depict interdependence of activities.3. It clearly distinguishes between critical and non-critical activities.4. It is not possible to crash activities to get optimum and minimum duration of the project.Which of the following statements given above are correct ?

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

4. Which one of the following is the best method for locating sounding to estimate the dredged material from the harbours ?

A.
Two angles from shore
B.
Two angles from boat
C.
One angle from shore and other from the boat
D.
Fixed intersecting ranges

5. An open channel carrying super critical flow is provided with a smooth expansion along the direction of flow. When no other considerations interfere, then the water surface.

A.
before transition will rise
B.
after transition will rise
C.
before transition will drop
D.
after transition will drop

6. A sewer is laid from a manhole A to a manhole B, 250 m apart along a downward gradient of 1 in 250. If the reduced level of the invert at A is 205.75 m and the height of the boring rod is 3 m, then, reduced level of the sight rail at B, is

A. 202.75 m
B. 206.75 m
C. 208.75 m
D. 211.75 m

7. A body of mass 4 kg moving at 12 m/s collides with another body of mass 8 kg and adheres to it. The resultant velocity of the total mass in m/s will be

A. 4.0
B. 5.0
C. 6.0
D. 7.0

8. A soil sample is having a specific gravity of 2.60 and a void ratio of 0.78. The water content in percentage required to fully saturate the soil at the void ratio would be

A. 10
B. 30
C. 50
D. 70

9. A rectangular channel carries a discharge of 5 m3/s. The channel is 2 m wide. What is the critical depth of the flow ?

A. 1.25 m
B. 1.07 m
C. 0.565 m
D. 0.86 m

10. The discharge per unit drawdown at the well is known as :

A. Specific yield
B. Specific storage
C. Specific retention
D. Specific capacity

11. At a certain point in a strained material, there are two mutually perpendicular stresses σx = 100 N/mm2 (Tensile) and σx = 50 N/mm2 (Compressive). [Notations : Tension (+); Compression (-) ]What are the values of the principal stresses in N/mm2 at that point ?

A. 100, -50
B. -100, 50
C. 75, -25
D. -75, 25

12. Which of the following materials are used as landfill salients for the control of gas and leachate moments ?1. Lime2. Sand3. Bentonite4. Fly ash5. Butyl rubberSelect the correct answer from the codes given below :

A. 1, 2 and 3
B. 4 and 5
C. 3 and 5
D. 1, 2 and 4

13. In a three-dimensional incompressible flow, the velocity component in the X and Y directions are u = 2x2 + z2 + 6 and v = y2 + 2z2 + 7. What is the velocity component in the z-direction ?

A. 2xz + 2yz + f(x, y)
B. 2xz + 4yz + f(x, y)
C. 4xz + 2yz + f(x, y)
D. - 4xz - 2yz + f(x, y)

14. Which one of the following shovel excavators is considered most efficient in loading carriers ?

A. Dipper shovel
B. Dragline
C. Backhoe
D. Clamshell

15. Brake is applied on a vehicle which then skids a distance of 16 m before coming to stop. If the developed average coefficient of friction between the tyres and the pavement is 0.4, then the speed of the vehicle before skidding would have been nearly

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

16. A right-angled triangular channel, symmetrical in section about the vertical, carries a discharge of 5 m3 /s with a velocity of 1.25 m/s. What is the approximate value of the Froude number of the flow ?

A. 0.3
B. 0.4
C. 0.5
D. 0.6

17. Which one of the following pairs is not correctly matched ?

A. Water losses....Evaporation
B. Runoff....Stream flow
C. Percolation....Soil Erosion
D. Storm....Precipitation

18. Which of the following pairs is correctly matched ?

A. Froude's number .... Intertial to surface tension force
B. Mach number .... Inertial to elastic force
C. Euler number .... Inertial to gravity force
D. Reynolds number .... Inertial to pressure force

19. A section of a solid circular shaft with diameter D is subjected to bending moment 'M' and torque (T). The expression for maximum principal stress at the section is

A.
B.
C.
D.

20. The flownet of activities of a project is shown in the given figure. The duration of the activities are written along the arrows. The critical path of the activities is along

A. 1-2-4-5-7-8
B. 1-2-3-5-7-8
C. 1-2-3-6-7-8
D. 1-2-4-5-3-6-7-8

21. Consider the following statement :1. Hydraulic gradient required to initiate "quick" condition is independent of the ratio of volume of voids of solids in a soil mass.2. Initiation of piping under hydraulic structures can be prevented by increasing the length of flow path of water.3. Seepage pressure is independent of the coefficient of permeability. Of these statement :

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

22. Which of the following waste disposal tasks are achieved by a septic tank with its dispersion tranch ?1. Aerobic sluge digestion2. Settling and anaerobic sludge digestion3. Anaerobic sewage stabilisation4. Bio-oxidation of effluentSelect the correct answer using the codes given below :

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

23. The expansion and shrinkage of plywoods are comparatively very low as

A. they are held in position by adhesives
B. they are glued under pressure
C. plies are placed at right angles to each other
D. they are prepared from veneers

24. Which one of the following methods is usually adopted for site welding of rails ?

A. Gas pressure welding
B. electric are welding
C. Thermit welding
D. Flash butt welding

25. In a simply supported beam AB of span L, the midpoint is C. In case-1, the beam is loaded by a central concentrated load W. In case-2, the beam is subjected to a U.D.L. of intensity w such that wL = W. The ratio of central deflection in case-1 to that in case-2 is

A. 5/3
B. 3/5
C. 5/8
D. 8/5

26. An imaginary line passing through the optical centre of the objective and the optical centre of the eye-piece in the telescope of a surveying instrument is called the

A. horizontal axis
B. line of collimation
C. optical axis of the telescope
D. reference axis

27. Which of the following air pollutants is/are responsible for photochemical smog ?1. Oxides of nitrogen2. Ozone3. Unburnt hydrocarbons4. Carbon monoxideSelect the correct answer from the codes given below :

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

28. Consider the following statements :Excess of sulphur in steel results in1. red shortness2. segregation 3. coldshortness.Of these statements :

A. 1 alone is correct
B. 2 alone is correct
C. 2 and 3 are correct
D. 1 and 2 are correct

29. Which one of the following pairs is not correctly matched ?

A. Declination : Horizontal angle between magnetic meridian & true meridian
B. Bowditch's rule : Employed to adjust closing error of a closed traverse
C. Deflection angle : Measured in case of open traverse instead of measuring included angle
D. Reconnaissance survey : Employed for detailed and precise survey

30. Consider the following statements :Some amount of chlorides is allowed in drinking water because1. it helps in killing bacteria.2. small quantity of chlorides adds to the taste3. it is not injurious to human health.4. it is not economical to remove it completely.Which of these statements are correct ?

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

31. A simply supported rectangular beam of span 'L' and depth 'd' carries a central load 'W' What ratio of maximum deflection to maximum bending stress is

A. L2/6Ed
B. L28Ed
C. L2/48Ed
D. L2/12Ed

32. A cantilever truss with joints labelled as 1, 2, and 3 is shown in the given figure. It carries a - vertical load of 10 kN at joint 2.

A.
B.
C.
D.

33. A short bar element of uniform cross-section is subjected to concentrated axial forces at its two ends. The longitudinal stress distribution on the cross-section is uniform at

A. all sections
B. the two ends only
C. the mid-section only
D. sections reasonably away from the two ends of the bar

34. When power shovels are operated under different site conditions (in terms of material handled), what is the correct sequence in the increasing order of the ouput for the following materials ?1. Well - blasted rock2. Hard and tough clay3. Poorly blasted rock4. Moist loam or sandSelect the correct answer using the code given below :

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

35. In a saturated clay layer undergoing consolidation with single drainage at its top, the pore water pressure would be the maximum at its

A. top
B. middle
C. bottom
D. top as well as the bottom

36. A flownet constructed to determine the seepage through an earth dam which is homogeneous but anisotropic, gave four flow channels and sixteen equipotential drops. The coefficients of permeability in the horizontal and vertical directions are 4 x 10-7 m/s and 1.0 x 10-7 m/s, respectively. If the storage head was 20 m, then the seepage per unit length of the dam (in m3/s) would be

A. 5 x 10-7
B. 10 x 10-7
C. 20 x 10-7
D. 40 x 10-7

37. A roaring rail has which one of the following defects ?

A. Split on head of rail
B. Minute depression and waves on the surface of rails
C. Split on web portion of rail
D. Square cracks on the surface of rail

38. While aligning a hill road with a ruling gradient of 1 in 20, horizontal curve of radius 80 m is encountered. The compensated gradient on the curve will be

A. 1 in 15
B. 1 in 17
C. 1 in 25
D. 1 in 27

39. Stratification of water with depth in reservoir (with free surface) is based on temperature. The dark stagnant cooler water layer is known as

A. Epilimnion
B. Hypolimnion
C. Metalimnion
D. Boundary

40. The following steps are involved in arriving at a unit hydrograph.1. Estimating the surface runoff in depth.2. Estimating the surface runoff in volume.3. Separation of base flow.4. Dividing surface runoff ordinates by depth of runoff.The correct sequence of the steps is :

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

41. What type of vibrator is used for concreting thin section as well as heavily reinforced section?

A. Vibrating needle
B. Internal vibrator
C. Surface vibrator
D. Form vibrator

42. The difference between the sum of the angles of a plane triangle and the sum of the angles of a spherical triangle is one second when the triangle on the earth surface has an area of about

A. 105 sq.km.
B. 135 sq.km.
C. 159 sq.km.
D. 195 sq.km.

43. Consider the following statements :1. The standard penetration test is a reliable method for measuring the relative density of granular soils.2. For a sand having the same relative density, N-values remain the same at all depths.3. For a sand having the same relative density, N-values are different at different depths.Which of the statements given above is/are correct ?

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

44. In a plane table survey, the plane table station position was to be fixed with respect to three reference points. It was found that one of the reference points was not visible due to some obstruction. It was, therefore decided to make use of the other two points only. Which one of the following statements is true regarding the determination of station position ?

A. The work can be done faster.
B. Two settings of the plane table will be needed but the work will be accurate.
C. Only one setting of the table is needed, however the work will be less accurate.
D. The work will be less accurate and time consuming.

45. Putty is made up of

B. powdered chalk and raw linseed oil
C. red lead and linseed oil
D. zinc oxide and boiled linseed oil

46. Why are weep holes provided at the back of retaining walls ?

A. To reduce the active earth pressure on the walls
B. To reduce the build - up of hydrostatic pressure
C. To provide better compaction
D. To increase the passive earth pressure

47. For the frame shown in the figure, the distribution factors for members BC and BA at joint B are

A. 0.4, 0.6
B. 0.5, 0.5
C. 0.6, 0.4
D. 0.7, 0.3

48. Force in the member AB of the frame shown in the given figure will be:

A. zero
B. W
C. W 2
D.

49. What should be the minimum grade of reinforced concrete in and around sea coast construction?

A. M 35
B. M 30
C. M 25
D. M 20

50. A sand deposit has a porosity of 1/3 and its specific gravity is 2.5. The critical hydraulic rediant to cause sand boiling in the stratum will be

A. 1.5
B. 1.25
C. 1.0
D. 0.75