Civil Engineering - RCC Structures Design MCQs Part 2

1. A T-beam behaves as a rectangular beam of a width equal to its flange if its neutral axis

A.
remains within the flange

B.
remains below the slab

C.
coincides the geometrical centre of the beam

D.
none of these.

 Answer Option A

2. The weight of a foundation is assumed as

A.
5% of wall weight

B.
7% of wall weight

C.
10% of wall weight

D.
12% of wall weight

 Answer Option C

3. The maximum shear stress (qmax) in a rectangular beam is

A.
1.25 times the average

B.
1.50 times the average

C.
1.75 times the average

D.
2.0 times the average

E.
2.5 times the average.

 Answer Option B

4. For stairs spanning horizontally, the minimum waist provided is

A.
4 cm

B.
6 cm

C.
8 cm

D.
10 cm

E.
12 cm.

 Answer Option E

5. Total pressure on the vertical face of a retaining wall of height h acts parallel to free surface and from the base at a distance of

A.
h/4

B.
h/3

C.
h/2

D.
2h/3

 Answer Option B

6. If the permissible compressive and tensile stresses in a singly reinforced beam are 50 kg/cm2 and 1400 kg/cm2 respectively and the modular ratio is 18, the percentage area At of the steel required for an economic section, is

A. 0.496%

B. 0.596%

C. 0.696%

D. 0.796%

E. none of these.

 Answer Option C

7. The live load to be considered for an inaccessible roof, is

A. Nil

B. 75 kg/m2

C. 150 kg/cm2

D. 200 kg/m2

 Answer Option B

8. If the maximum shear stress at the end of a simply supported R.C.C. beam of 6 m effective span is 10 kg/cm2, the share stirrups are provided for a distance x from either end where x is

A. 50 cm

B. 100 cm

C. 150 cm

D. 200 cm

 Answer Option C

9. The radius of a bar bend to form a hook, should not be less than

A. twice the diameter

B. thrice the diameter

C. four times the diameter

D. five times the diameter

E. none of these.

 Answer Option A

10. With usual notations the depth of the neutral axis of a balanced section, is given by

A.

B. t/mc = n/(d-n)

C.

D.

 Answer Option D

11. In a simply supported slab the minimum spacing of distribution reinforcement, should be four times the effective thickness of the slab or

A. 20 cm

B. 30 cm

C. 40 cm

D. 50 cm

E. 60 cm

 Answer Option E

12. A reinforced concrete cantilever beam is 3.6 m long, 25 cm wide and has its lever arm 40 cm. It carries a load of 1200 kg at its free end and vertical stirrups can carry 1800 kg. Assuming concrete to carry one-third of the diagonal tension and ignoring the weight of the beam, the number of shear stirrups required, is

A. 30

B. 35

C. 40

D. 45

E. 50

 Answer Option C

13. If the sides of a slab simply supported on edges and spanning in two directions are equal, the maximum bending moment is multiplied by

A. 0.2

B. 0.3

C. 0.4

D. 0.5

E. 0.7

 Answer Option D

14. An R.C.C. beam of 25 cm width and 50 cm effective depth has a clear span of 6 metres and carries a U.D.L. of 3000 kg/m inclusive of its self weight. If the lever arm constant for the section is 0.865, the maximum intensity of shear stress, is

A. 8.3 kg/cm2

B. 7.6 kg/cm2

C. 21.5 kg/cm2

D. 11.4 kg/cm2

 Answer Option A

15. If the ratio of the span to the overall depth does not exceed 10, the stiffness of the beam will ordinarily be satisfactory in case of a

A. simply supported beam

B. continuous beam

C. cantilever beam

D. none of these.

 Answer Option C

16. The toe projection of foundation slabs is taken

A. as one third of the base

B. as one sixth of overall height of the wall

C. equal to heel slab

D. below ground surface.

 Answer Option A

17. For stairs spanning l metres longitudinally between supports at the bottom and top of a flight carrying a load w per unit horizontal area, the maximum bending moment per metre width, is

A.

B.

C.

D.

E.

 Answer Option E

18. Steel beam theory is used for

A. design of simple steel beams

B. steel beams encased in concrete

C. doubly reinforced beams ignoring compressive stress in concrete

D. beams if shear exceeds 4 times allowable shear stress.

 Answer Option C

19. The advantage of reinforced concrete, is due to

A. monolithic character

B. fire-resisting and durability

C. economy because of less maintenance cost

D. moulding in any desired shape

E. All the above.

 Answer Option E

20. The shear reinforcement in R.C.C. is provided to resist

A. vertical shear

B. horizontal shear

C. diagonal compression

D. diagonal tension.

 Answer Option D

21. An R.C.C. column of 30 cm diameter is reinforced with 6 bars 12 mm φ placed symmetrically along the circumference. If it carries a load of 40, 000 kg axially, the stress is

A. 49.9 kg/cm2

B. 100 kg/cm2

C. 250 kg/cm2

D. 175 kg/cm2

 Answer Option A

22. According to I.S.: 456, 1978 the thickness of reinforced concrete footing on piles at its edges, is kept less than

A. 20 cm

B. 30 cm

C. 40 cm

D. 50 cm

E. 75 cm

 Answer Option B

23. The width of the rib of a T-beam, is generally kept between

A.

B.

C.

D.

 Answer Option D

24. Pick up the true statement from the following:

A. Plain ceiling provides the best property diffusing light

B. In the absence of beams, it is easier to install piping

C. In the absence of beams, it is easier to paint

D. A flat slab is capable to withstand concentrated loads

E. All the above.

 Answer Option E

25. A pile of length L carrying a uniformly distributed load W per metre length is suspended at two points, the maximum, B.M. at the centre of the pile or at the points of suspension, is

A.

B.

C.

D.

E.

 Answer Option C

26. If bending moment is M, shear force is F effecive depth is d, lever arm is la area of reinforcement is As and sum of the circumferences of main reinforcement is 0, the bond stress based on working stress method, is

A.

B.

C.

D.

 Answer Option A

27. The horizontal portion of a step in a stairs case, is known as

A. rise

B. flight

C. winder

D. tread.

 Answer Option D

28. The length of lap in tension reinforcement should not be less than the bar diameter x (actual tension / four times the permissible average bond stress) if it is more than

A. 18 bar diameters

B. 24 bar diameters

C. 30 bar diameters

D. 36 bar diameters

 Answer Option C

29. If K is a constant depending upon the ratio of the width of the slab to its effective span l, x is the distance of the concentrated load from the nearer support, bw is the width of the area of contact of the concentrated load measured parallel to the supported edge, the effective width of the slab be is

A.

B.

C.

D.

E. All the above.

 Answer Option B

30. If W is total load per unit area on a panel, D is the diameter of the column head, L is the span in two directions, then the sum of the maximum positive bending moment and average of the negative bending moment for the design of the span of a square flat slab, should not be less than

A.

B.

C.

D.

 Answer Option C

31. Distribution reinforcement in a simply supported slab, is provided to distribute

A. load

B. temperature stress

C. shrinkage stress

D. all the above.

 Answer Option D

32. To ensure that the hogging bending moment at two points of suspension of a pile of length L equals the sagging moment at its centre, the distances of the points of suspension from either end, is

A. 0.107 L

B. 0.207 L

C. 0.307 L

D. 0.407 L

 Answer Option B

33. The thickness of the topping of a ribbed slab, varies between

A. 3 cm to 5 cm

B. 5 cm to 8 cm

C. 8 cm to 10 cm

D. 12 cm to 15 cm

E. 12 cm to 18 cm

 Answer Option B

34. To ensure uniform pressure distribution, the thickness of the foundation, is

A. kept uniform throughout

B. increased gradually towards the edge

C. decreased gradually towards the edge

D. kept zero at the edge.

 Answer Option C

35. The maximum ratio of span to depth of a cantilever slab, is

A. 8

B. 10

C. 12

D. 14

E. 16

 Answer Option C

36. Pick up the incorrect statement from the following. The intensity of horizontal shear stress at the elemental part of a beam section, is directly proportional to

A. shear force

B. area of the section

C. distance of the C.G. of the area from its neutral axis

D. moment of the beam section about its neutral axis

E. width of the beam.

 Answer Option D

37. In a singly reinforced beam, the effective depth is measured from its compression edge to

A. tensile edge

B. tensile reinforcement

C. neutral axis of the beam

D. longitudinal central axis.

 Answer Option B

38. If a rectangular prestressed beam of an effective span of 5 meters and carrying a total load 3840 kg/m, is designed by the load balancing method, the central dip of the parabolic tendon should be

A. 5 cm

B. 10 cm

C. 15 cm

D. 20 cm

E. 25 cm

 Answer Option B

39. The depth of the centre of gravity (y) of the resultant compressive stress from the compression edge of the T-beam specified in Q. 13.52 is given by

A.

B.

C.

D.

 Answer Option D

40. If the maximum shear stress at the end of a simply supported R.C.C. beam of 16 m effective span is 10 kg/cm2, the length of the beam having nominal reinforcement, is

A. 4 cm

B. 6 m

C. 8 m

D. 10 m

 Answer Option C

41. If the diameter of longitudinal bars of a square column is 16 mm, the diameter of lateral ties should not be less than

A. 4 mm

B. 5 mm

C. 6 mm

D. 8 mm

E. 10 mm

 Answer Option B

42. If the depth of actual neutral axis of a doubly reinforced beam

A. is greater than the depth of critical neutral axis, the concrete attains its maximum stress earlier

B. is less than the depth of critical neutral axis, the steel in the tensile zone attains its maximum stress earlier

C. is equal to the depth of critical neutral axis, the concrete and steel attain their maximum stresses simultanesouly

D. all the above.

 Answer Option D

43. The length of the straight portion of a bar beyond the end of the hook, should be at least

A. twice the diameter

B. thrice the diameter

C. four times the diameter

D. five times the diameter

E. seven times the diameter.

 Answer Option E

44. A simply supported beam , 6 m long and of effective depth 50 cm, carries a uniformly distributed load 2400 kg/m including its self weight. If the lever arm factor is 0.85 and permissible tensile stress of steel is 1400 kg/cm2, the area of steel required, is

A. 14 cm2

B. 15 cm2

C. 16 cm2

D. 17 cm2

E. 18 cm2

 Answer Option C

45. If p1 is the vertical intensity of pressure at a depth h on a block of earth weighing w per unit volume and the angle of repose φ, the lateral intensity of pressure p2 is

A.

B.

C.

D.

 Answer Option B

46. A pile of length L carrying a uniformly distributed load W per metre length is suspended at the centre and from other two points 0.15 L from either end ; the maximum hogging moment will be

A.

B.

C.

D.

E.

 Answer Option D

47. Distribution of shear intensity over a rectangular section of a beam, follows :

A. a circular curve

B. a straight line

C. a parabolic curve

D. an elliptical curve

E. none of these.

 Answer Option C

48. [A + (m - 1)ASC] known as equivalent concrete area of R.C.C. is given by

A. modular ratio method

B. load factor method

C. ultimate load method

D. none of these.

 Answer Option A

49. Pick up the incorrect statement from the following: Tensile reinforcement bars of a rectangular beam

A. are curtailed if not required to resist the bending moment

B. are bent up at suitable places to serve as shear reinforcement

C. are bent down at suitable places to serve as shear reinforcement

D. are maintained at bottom to provide at least local bond stress.

 Answer Option C

50. The maximum diameter of a bar used in a ribbed slab, is

A. 12 mm

B. 6 mm

C. 20 mm

D. 22 mm

E. 24 mm

 Answer Option D