Civil Engineering - RCC Structures Design MCQs Part 5

1. A ribbed slab is provided for

A.
a plain ceiling

B.
thermal insulation

C.
acoustic insulation

D.
all the above.

 Answer Option D

2. For a number of columns constructed in a rcjw, the type of foundation provided, is

A.
footing

B.
raft

C.
strap

D.
strip

E.
a combination of the above.

 Answer Option D

3. As the percentage of steel increases

A.
depth of neutral axis decreases

B.
depth of neutral axis increases

C.
lever arm increases

D.
lever arm decreases

E.
none of these.

 Answer Option B

4. If W is weight of a retaining wall and P is the horizontal earth pressure, the factor of safety against sliding, is

A.
1.0

B.
1.25

C.
1.5

D.
2.0

E.
2.5

 Answer Option C

5. If q is the punching shear resistance per unit area a, is the side of a square footing for a column of side b, carrying a weight W including the weight of the footing, the depth (D) of the footing from punching shear consideration, is

A.

B.

C.

D.

 Answer Option B

6. Based on punching shear consideration, the overall depth of a combined footing under a column A, is

A.

B.

C.

D. None of these.

 Answer Option B

7. An intermediate T-beam reinforced with two layers of tensile steel with clear cover 13 cm encasted with the floor of a hall 12 metres by 7 metres, is spaced at 3 metres from adjoining beams and if the width of the beam is 20 cm, the breadth of the flange is

A. 300 cm

B. 233 cm

C. 176 cm

D. 236 cm

E. 255 cm

 Answer Option C

8. Pick up the assumption for the design of a prestressed concrete member from the following :

A. A transverse plane section remains a plane after bending

B. During deformation limits, Hook's law is equally applicable to concrete as well as to steel

C. Variation of stress in reinforcement due to changes in external loading is negligible

D. All the above.

 Answer Option D

9. If the diameter of the main reinforcement in a slab is 16 mm, the concrete cover to main bars is

A. 12 mm

B. 13 mm

C. 14 mm

D. 15 mm

E. 16 mm

 Answer Option E

10. Side face reinforcement shall be provided in the beam when depth of the web in a beam exceeds

A. 50 cm

B. 75 cm

C. 100 cm

D. 120 cm

 Answer Option B

11. The stresses developed in concrete and steel in reinforced concrete beam 25 cm width and 70 cm effective depth, are 62.5 kg/cm2 and 250 kg/cm2 respectively. If m = 15, the depth of its neutral axis is

A. 20 cm

B. 25 cm

C. 30 cm

D. 35 cm

E. 40 cm

 Answer Option C

12. If the ratio of long and short spans of a two way slab with corners held down is r, the actual reduction of B.M. is given by

A.

B.

C.

D.

E. none of these.

 Answer Option D

13. The angle of repose of a soil is the maximum angle which the outer face of the soil mass makes

A. with the horizontal

B. with the vertical

C. with the perpendicular to. the inclined plane of the soil

D. none of these.

 Answer Option A

14. A column is regarded as long column if the ratio of its effective length and lateral dimension, exceeds

A. 10

B. 15

C. 20

D. 25

E. 30

 Answer Option B

15. Enlarged head of a supporting column of a flat slabs is technically .known as

A. supporting end of the column

B. top of the column

C. capital

D. drop panel

E. none of these.

 Answer Option C

16. If the length of a combined footing for two columns l metres apart is L and the projection on the left side of the exterior column is x, then the projection y on the right side of the exterior column, in order to have a uniformly distributed load, is (where x is the distance of centre of gravity of column loads).

A. y = L - (l - x)

B.

C.

D.

 Answer Option D

17. The section of a reinforced beam where most distant concrete fibre in compression and tension in steel attains permissible stressess simultaneously, is called

A. balanced section

B. economic section

C. critical section

D. all the above.

 Answer Option D

18. The width of the flange of a L-beam, should be less than

A. one-sixth of the effective span

B. breadth of the rib + four times thickness of the slab

C. breadth of the rib + half clear distance between ribs

D. least of the above.

 Answer Option D

19. If the maximum dip of a parabolic tendon carrying tension P is h and the effective length of the prestressed beam is L, the upward uniform pressure will be

A.

B.

C.

D.

E.

 Answer Option B

20. A singly reinforced concrete beam of 25 cm width and 70 cm effective depth is provided with 18.75 cm2 steel. If the modular ratio (m) is 15, the depth of the neutral axis, is

A. 20 cm

B. 25 cm

C. 30 cm

D. 35 cm

E. 40 cm

 Answer Option C

21. The weight of reinforced concrete, is generally taken as

A. 2200 kg/m3

B. 2300 kg/m3

C. 2400 kg/m3

D. 2500 kg/m3

E. 2800 kg/m3

 Answer Option C

22. Total pressure on the vertical face of a retaining wall of height h per unit run exerted by the retained earth weighing w per unit volume, is

A.

B.

C.

D.

 Answer Option C

23. The zone in which transverse bending is likely to occur may be obtained by drawing a line from the faces of the column making an angle θ° with horizontal where θ° is

A. 30°

B. 45°

C. 60°

D. none of these.

 Answer Option B

24. If P kg/m2 is the upward pressure on the slab of a plain concrete footing whose projection on either side of the wall is a cm, the depth of foundation D is given by

A. D = 0.00775 aP

B. D = 0.0775 aP

C. D = 0.07775 aP

D. D = 0.775 Pa

 Answer Option A

25. According to load factor method, the permissible load W on a short column reinforced with longitudinal bars and lateral stirrups, is

A. Stress in concrete x area of concrete

B. Stress in steel x area of steel

C. Stress in concrete x area of concrete + Stress in steel x area of steel

D. None of these.

 Answer Option C

26. If A is the area of the foundation of a retaining wall carrying a load W and retaining earth of weight w per unit volume, the minimum depth (h) of the foundation from the free surface of the earth, is

A.

B.

C.

D.

 Answer Option C

27. In a cantilever retaining wall without a heel slab

A. thickness of the stem is kept same throughout

B. base slab is made 10 cm thicker than the stem

C. width of the base slab is kept 0.7 time the total height of the wall

D. all the above.

 Answer Option D

28. The design of heel slab of a retaining wall, is based on the maximum bending moment due to:

A. its own weight

B. weight of the soil above it,

C. load of the surcharge, if any

D. upward soil reaction

E. all the above.

 Answer Option E

29. If the modular ratio is m, steel ratio is r and overall depth of a beam is d, the depth of the critical neutral axis of the beam, is

A.

B.

C.

D.

E.

 Answer Option B

30. A per IS : 1343, total shrinkage for a pretensioned beam, is

A. 3.0 x 10-2

B. 3.0 x 10-3

C. 3.0 x 10-4

D. 3.0 x 10-5

E. 3.5 x 10-5

 Answer Option E

31. The Young's modulus of elasticity of steel, is

A. 150 KN/mm2

B. 200 KN/mm2

C. 250 KN/mm2

D. 275 KN/mm2

 Answer Option B

32. The maximum permissible size of aggregates to be used in casting the ribs of a slab, is

A. 5 mm

B. 7.5 mm

C. 10 mm

D. 15 mm

E. 20 mm

 Answer Option C

33. In a simply supported slab, alternate bars are curtailed at

A. 1/4th of the span

B. 1/5th of the span

C. 1/6th of the span

D. 1/7th of the span

E. none of these.

 Answer Option D

34. The diameter of main bars in R.C.C. columns, shall not be less than

A. 6 mm

B. 8 mm

C. 10 mm

D. 12 mm

 Answer Option D

35. The breadth of a ribbed slab containing two bars must be between

A. 6 cm to 7.5 cm

B. 8 cm to 10 cm

C. 10 cm to 12 cm

D. 12 cm to 15 cm

E. none of these.

 Answer Option B

36. The minimum thickness of the cover at the end of a reinforcing bar should not be less than twice the diameter of the bar subject to a minimum of

A. 10 mm

B. 15 mm

C. 20 mm

D. 25 mm

E. 30 mm

 Answer Option D

37. If l1 and l2 are the lengths of long and short spans of a two way slab simply supported on four edges and carrying a load w per unit area, the ratio of the loads split into w1 and w2 acting on strips parallel to l2 and l1 is

A.

B.

C.

D.

 Answer Option D

38. If L is the effective span of a R.C.C. beam which is subjected to maximum shear qmax at the ends, the distance from either end over which stirrups for the shear, are provided, is

A.

B.

C.

D.

 Answer Option C

39. For the design of a simply supported T-beam the ratio of the effective span to the overall depth of the beam is limited to

A. 10

B. 15

C. 20

D. 25

E. 30

 Answer Option C

40. In the zone of R.C.C. beam where shear stress is less than 5 kg/cm2, nominal reinforcement is provided at a pitch of

A. one-half lever arm of the section

B. one-third lever arm of the section

C. lever arm of the section

D. one and half lever arm of the section.

 Answer Option C

41. P is the prestressed force applied to tendon of a rectangular prestressed beam whose area of cross section is A and sectional modulus is Z. The minimum stress f on the beam subjected to a maximum bending moment M is

A.

B.

C.

D.

E.

 Answer Option C

42. In a singly reinforced beam

A. compression is borne entirely by concrete

B. steel possesses initial stresses when em-beded in concrete

C. plane sections transverse to the centre line of the beam before bending remain plane after bending

D. elastic modulii for concrete and steel have different values within the limits of deformation of the beam

E. none of these.

 Answer Option C

43. A pre-cast pile generally used, is

A. circular

B. square

C. octagonal

D. square with corners chamfered.

 Answer Option D

44. On an absolutely rigid foundation base, the pressure will

A. be more at the edges of the foundation

B. be uniform

C. not be uniform

D. be zero at the centre of the foundation.

 Answer Option C

45. As per IS : 456, the reinforcement in a column should not be less than

A. 0.5% and not more than 5% of cross-sec-tional area

B. 0.6% and not more than 6% of cross-see-tional area

C. 0.7% and not more than 7% of cross-sec-tional area

D. 0.8% and not more than 8% of cross-sectional area

E. none of these.

 Answer Option D

46. If T and R are the tread and rise of a stair which carries a load w per square metre on slope, the corresponding load per square metre of the horizontal area, is

A.

B.

C.

D.

E.

 Answer Option B

47. If the bearing capacity of soil is 10 tonnes/cm2 and the projection of plain concrete footing from walls, is a cm, the depth D of footing is

A. D = 0.0775 a

B. D = 0.775 a

C. D = 0.775a

D. D = 0.775 a2

 Answer Option B

48. An R.C.C. lintel is spanning an opening of 2 m span in a brick wall. The height of the roof is 2.9 m above the floor level and that of the opening is 2.1 m above the floor level. The lintel is to be designed for self weight plus

A. triangular load of the wall

B. UDL of wall

C. UDL of wall + load from the roof

D. triangular load + load from the roof.

 Answer Option C

49. The pitch of the main bars in a simply supported slab, should not exceed its effective depth by

A. three times

B. four times

C. five times

D. six times

E. seven times.

 Answer Option D