1000+ Design of Steel Structures Multiple Choice Question Answer [Solved]

1. Load factor is
A. Always equal to factor of safety
B. Always less than factor of safety
C. Always greater than factor of safety
D. Sometimes greater than factor of safety
Answer : C

2. Pick up the correct statement from the following:
A. Tacking rivets are used if the minimum distance between centres of two adjacent rivets exceeds 12 t or 200 mm, whichever is less
B. Tacking rivets are not considered to calculate stress
C. Tacking rivets are provided throughout the length of a compression member composed of two components back to back
D. All the above
Answer : D

3. The ratio of longitudinal stress to strain within elastic limit, is known as
A. Modulus of elasticity
B. Shear modulus of elasticity
C. Bulk modulus of elasticity
D. All the above
Answer : A

4. The difference between gross diameter and nominal diameter for the rivets up to 25 mm diameter is
A. 1.0 mm
B. 1.5 mm
C. 2.0 mm
D. 2.5 mm
Answer : B

5. A fillet weld may be termed as
A. Mitre weld
B. Concave weld
C. Convex weld
D. All the above
Answer : D

6. According to the Unwin's formula, if t is thickness of the plate in mm, the nominal diameter of the rivet, is
A. d = 1.91 t
B. d = 1.91 t2
C. d = 1.91 ?t
D. d = 1.91 ?t
Answer : C

7. If a pair of angles placed back to back in tension are connected by one leg of each angle, the net effective area of the section, is
A. a - [b/{1 + 0.35 (b/a)}]
B. a + [b/{1 + 0.35 (b/a)}]
C. a - [b/{1 + 0.2 (b/a)}]
D. a + [b/{1 + 0.2 (b/a)}]
Answer : D

8. In moment resistant connections, the moment resistance of riveted connection depends upon
A. Shear in rivets
B. Compression in rivets
C. Tension in rivets
D. Strength of rivets in bearing
Answer : C

9. If the thickness of plate to be connected by a rivet is 16 mm, then suitable size of rivet as per Unwin's formula will be
A. 16 mm
B. 20 mm
C. 24 mm
D. 27 mm
Answer : C

10. Efficiency of a riveted joint is defined as the ratio of
A. Least strength of a riveted joint to the strength of solid plate
B. Greatest strength of a riveted joint to the strength of solid plate
C. Least strength of a riveted plate to the greatest strength of the riveted joint
D. All the above
Answer : D

11. Rolled steel angle sections are classified as
A. Equal angles
B. Unequal angles
C. Bulb angles
D. All the above
Answer : D

12. The greatest permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
A. 180 t
B. 220 t
C. 230 t
D. 270 t
Answer : D

13. Length of an outstanding leg of a vertical stiffener, may be taken equal to
A. 1/10th of clear depth of the girder plus 15 mm
B. 1/20th of clear depth of the girder plus 20 mm
C. 1/25th of clear depth of the girder plus 25 mm
D. 1/30th of clear depth of the girder plus 50 mm
Answer : C

14. The connection of one beam to another beam by means of an angle at the bottom and an angle at the top, is known as
A. Unstiffened seated connection
B. Stiffened seated connection
C. Seated connection
D. None of these
Answer : C

15. For a cantilever beam of length L continuous at the support and unrestrained against torsion at the support and free at the end, the effective length l is equal to
A. l = L
B. l = 2L
C. l = 0.5L
D. l = 3L
Answer : D

16. Rivets connecting flange angles to cover plates in a plate girder are subjected to
A. Horizontal shear only
B. Vertical load only
C. Both (A) and (B)
D. None of the above
Answer : A

17. The permissible stress in bending for rolled steel I-beams and channels, is
A. 1500 kg/cm²
B. 1575 kg/cm²
C. 945 kg/cm²
D. 1650 kg/cm²
Answer : D

18. The slenderness ratio of a column is zero when its length
A. Is zero
B. Is equal to its radius of gyration
C. Is supported on all sides throughout its length
D. Is between the points of zero moments
Answer : D

19. Design of a riveted joint, is based on the assumption:
A. Load is uniformly distributed among all the rivets
B. Shear stress on a rivet is uniformly distributed over its gross area
C. Bearing stress in the rivet is neglected
D. All the above
Answer : D

20. The gross diameter of a rivet is the diameter of
A. Cold rivet before driving
B. Rivet after driving
C. Rivet hole
D. None of these
Answer : B

21. The mechanism method and the statical method give
A. Lower and upper bounds respectively on the strengthof structure
B. Upper and lower bounds respectively on the strength of structure
C. Lower bound on the strength of structure
D. Upper bound on the strength of structure
Answer : B

22. A beam may be designed as a cased beam if
A. Section is of double open channel form with the webs not less than 40 mm apart
B. Overall depth and width of the steel section do not exceed 750 and 450 mm respectively
C. Beam is solidly encased in concrete with 10 mm aggregate having 28 days strength 160 kg/cm2
D. All the above
Answer : D

23. For rivets in tension with countersunk heads, the tensile value shall be
A. Reduced by 25 %
B. Reduced by 33.3%
C. Increased by 25 %
D. Increased by 33.3 %
Answer : B

24. In case horizontal stiffeners are not used, the distance between vertical legs of flange angles at the top and bottom of a plate girder, is known as
A. Overall depth
B. Clear depth
C. Effective depth
D. None of these
Answer : B

25. In plastic analysis, the shape factor for circular sections, is
A. 1.5
B. 1.6
C. 1.697
D. None of these
Answer : C

26. When the length of a tension member is too long
A. A wire rope is used
B. A rod is used
C. A bar is used
D. A single angle is used
Answer : C

27. Bending compressive and tensile stresses respectively are calculated based on
A. Net area and gross area
B. Gross area and net area
C. Net area in both cases
D. Gross area in both cases
Answer : B

28. The moment of the couple set up in a section of a beam by the longitudinal compressive and tensile force, is known as
A. Bending moment
B. Moment of resistance
C. Flexural stress moment
D. None of these
Answer : B

29. As per IS: 800, in the plastic design, which of the following pairs are correctly matched?
Working Loads Load factor
(i) Dead load 1.7
(ii) Dead Load + imposed load 1.7
(iii) Dead load + load due to wind or 1.3 seismic forces
(iv) Dead load + imposed load + load 1.7 due to wind or seismic forces
Of these statements
A. (i) and (ii) are correct
B. (i), (ii) and (iii) are correct
C. (ii) and (iii) are correct
D. Only (i) is correct
Answer : A

30. The basic wind speed is specified at a height 'h' above mean ground level in an open terrain. The value of 'h' is
A. 10 m
B. 20 m
C. 25 m
D. 50 m
Answer : A

31. If f_bt and f_c are the co-existent bending tensile stress and shear stress in a member, the equivalent stress f_c is
A. ?(f_bt² + f_c²)
B. ?(f_bt² + ½f_c²)
C. ?(f_bt² + 3f_c²)
D. ?(f_bt² - 3f_c²)
Answer : C

32. In case of plastic design, the calculated maximum shear capacity of a beam as per IS: 800 shall be
A. 0.55 Aw.fy
B. 0.65 Aw.fy
C. 0.75 Aw.fy
D. 0.85 Aw.fy Where, Aw = effective cross-sectional area resisting shear fy = yield stress of the steel
Answer : A

33. When the axis of load lies in the plane of rivet group, then the rivets are subjected to
A. Only shear stresses
B. Only tensile stresses
C. Both (A) and (B)
D. None of the above
Answer : A

34. The cross-section of a standard fillet is a triangle whose base angles are
A. 45° and 45°
B. 30° and 60°
C. 40° and 50°
D. 20° and 70°
Answer : A

35. Stiffeners are used in a plate girder
A. To reduce the compressive stress
B. To reduce the shear stress
C. To take the bearing stress
D. To avoid bulking of web plate
Answer : D

36. The distance between the outer faces of flanges of a plate girder, is known as
A. Overall depth
B. Clear depth
C. Effective depth
D. None of these
Answer : A

37. In a gusseted base, when the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate
A. Fully by direct bearing
B. Fully through fastenings
C. 50% by direct bearing and 50% through fastenings
D. 75% by direct bearing and 25% through fastenings
Answer : C

38. Pick up the correct statement from the following:
A. Dead load includes self-weight of the structure and super-imposed loads permanently attached to the structure
B. Dead loads change their positions and vary in magnitude
C. Dead loads are known in the beginning of the design
D. None of these
Answer : A

39. The thickness t of a single flat lacing should not be less than
A. 1/30th length between inner end rivets
B. 1/40th length between inner end rivets
C. 1/50th length between inner end rivets
D. 1/60th length between inner end rivets
Answer : B

40. For a rectangular section, the ratio of the maximum and average shear stresses, is
A. 1.5
B. 2.0
C. 2.5
D. 3.5
Answer : A

41. Slenderness ratio of a compression member is
A. Moment of inertia/Radius of gyration
B. Effective length/Area of cross-section
C. Radius of gyration/Effective length
D. Radius of gyration/ Area of cross-section
Answer : C

42. A circular column section is generally not used in actual practice because
A. It is uneconomical
B. It cannot carry the load safely
C. It is difficult to connect beams to the round sections
D. All of the above
Answer : C

43. The maximum permissible span of asbestos cement sheets is
A. 650 mm
B. 810 mm
C. 1250 mm
D. 1680 mm
Answer : D

44. Maximum permissible slenderness ratio of a member normally acting as a tie in a roof truss, is
A. 180
B. 200
C. 250
D. 350
Answer : D

45. The ratio of hydrostatic stress to the volumetric strain within the elastic range, is called
A. Modulus of elasticity
B. Shear modulus of elasticity
C. Bulk modulus of elasticity
D. All the above
Answer : D

46. The main advantage of a steel member, is:
A. Its high strength
B. Its gas and water tightness
C. Its long service life
D. All the above
Answer : D

47. Lug angles
A. Are used to reduce the length of connection
B. Are unequal angles
C. Increases shear lag
D. All the above
Answer : A

48. Select the correct statement
A. Material cost of a rivet is higher than that of a bolt
B. Tensile strength of a bolt is lesser than that of a rivet
C. Bolts are used as a temporary fastening whereas rivets are used as permanent fastenings
D. Riveting is less noisy than bolting
Answer : C

49. The permissible bearing stress in steel, is
A. 1500 kg/cm2
B. 1890 kg/cm2
C. 2025 kg/cm2
D. 2340 kg/cm2
Answer : B

50. For the steel member exposed to weather and accessible for repainting, the thickness of steel should not be less than (accepting the webs of Indian Standard rolled steel joists and channels).
A. 4 mm
B. 6 mm
C. 8 mm
D. 10 mm
Answer : B