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

1. If R is the reaction on the bearing plate, the minimum moment of. inertia of the bearing stiffener provided at the support of a plate girder of overall depth D, the maximum thickness of the compression flange T, carrying total load W, is
A. (D²/250) × (R/W)
B. (D³T/250) × (R/W)
C. (DT/250) × (R/W)
D. (DT/250) × (W/R)
Answer : B

2. If N is the number of rivets in the joint, the strength of a riveted joint against shearing of rivets, is given by
A. P_s = N × (?/4) d² × P_s
B. P_s = N × (d × t × p_s)
C. P_s = N × (p - d) × t × P_s
D. P_s = N × (P + d) × t × p_s
Answer : A

3. The average shear stress for rolled steel beam section, is
A. 845 kg/cm²
B. 945 kg/cm²
C. 1025 kg/cm²
D. 1500 kg/cm²
Answer : B

4. The tensile strength of mild steel for bolts and nuts should not be less than
A. 32 kg/mm²
B. 36 kg/mm²
C. 40 kg/mm²
D. 44 kg/mm²
Answer : D

5. The effective length L of a simply supported beam with ends restrained against torsion, and also the ends of compression flange partially restrained against lateral bending, is given by
A. L = span
B. L = 0.85 span
C. L = 0.75 span
D. L = 0.7 span
Answer : B

6. Study the following statements. (i) Top lateral bracing prevents the sides-way buckling of the chord. (ii) Sway bracing keeps the rectangular shape of the bridge crosssection. (iii) Sway bracing transfers the load from top of end posts to bearings. The correct answer is
A. Only (i)
B. Both (i) and (ii)
C. Both (i) and (iii)
D. All (i), (ii) and (iii)
Answer : B

7. The diameter of base of conical flare of a steel stack is
A. Less than d
B. Equal to d
C. More than d
D. Any of the above Where d is the diameter of the cylindrical part
Answer : C

8. The range of economical spacing of trusses varies from
A. L/3 to L/5
B. L/4 to 2L/5
C. L/3 to L/2
D. 2L/5 to 3L/5, where L is span
Answer : A

9. The economical depth d of a web plate in which allowable bearing stress is f_b, and the maximum bending moment is M, as suggested by Rawater and Clark, is
A. d = ?(M/f_b)
B. d = 1.5 ?(M/f_b)
C. d = 2.5 ?(M/f_b)
D. d = 4.5 ?(M/f_b)
Answer : D

10. The shape factor of an isosceles triangle for bending about the axis parallel to the base is:
A. 1.5
B. 1.7
C. 2.0
D. 2.34
Answer : D

11. Effective length of a column effectively held in position at both ends and restrained in direction at one end, is
A. L
B. 0.67 L
C. 0.85 L
D. 1.5 L
Answer : C

12. The effective length of a compression member of length L held in position at both ends but not restrained in direction, is
A. L
B. 0.67 L
C. 0.85 L
D. 1.5 L
Answer : A

13. Bulb angles are used in
A. Column building
B. Bridge building
C. Ship building
D. Water tank building
Answer : C

14. Pitch of tacking rivets, when double angles connected back to back and acting as tension members should not be more than
A. 500 mm
B. 600 mm
C. 1000 mm
D. 300 mm
Answer : C

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

16. For a steel member of slenderness ratio 350, the allowable stress is 76 kg/cm2 if it is
A. HTW grade of thickness exceeding 32 mm
B. HT grade of thickness exceeding 45 mm
C. HT grade of thickness not exceeding 45 mm
D. All the above
Answer : D

17. The bending moment for filler joists at the middle of an intermediate span, is
A. WL²/10
B. - WL²/10
C. - WL²/12
D. WL²/12
Answer : D

18. The spans are considered approximately equal if the longest span does not exceed the shortest span by more than
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : C

19. To minimize the total cost of a roof truss, the ratio of the cost of truss to the cost of purlins shall be
A. 1
B. 2
C. 3
D. 4
Answer : B

20. For steel members not exposed to weather, the thickness of steel should not be less than
A. 4.5 mm
B. 6 mm
C. 8 mm
D. 10 mm
Answer : B

21. 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 f 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

22. If the floor is supported at or near the bottom but top chords of a bridge is not braced, then the bridge is called
A. Deck type
B. Through type
C. Half through type
D. Double deck type
Answer : C

23. When the depth of a plate girder is at least n times the depth of vertical leg of the flange angles, the girder is known as deep plate girder, if n is
A. 2
B. 4
C. 6
D. 8
Answer : D

24. Pick up the incorrect statement from the following:
A. The nominal diameter of a rivet is its diameter before driving
B. The gross diameter of a rivet is the diameter of rivet hole
C. The gross area of a rivet is the cross-sectional area of the rivet hole
D. The diameter of a rivet hole is equal to the nominal diameter of the rivet plus 1.5 mm
Answer : D

25. According to IS: 800, in the Merchant Rankine formula the value of imperfection index (n) is
A. 1.0
B. 1.4
C. 1.8
D. 2.0
Answer : B

26. An imaginary line along which rivets are placed, is known as
A. Rivet line
B. Back line
C. Gauge line
D. All the above
Answer : D

27. Rise of a Jack arch is kept about
A. 1/2 to 1/3 of the span
B. 1/3 to 1/4 of the span
C. 1/4 to 1/8 of the span
D. 1/8 to 1/12 of the span
Answer : D

28. In case of cantilever fillers, the ratio of the span L to depth d, should not exceed
A. 4
B. 8
C. 12
D. 16
Answer : C

29. Strengths of a rivet in single shearing, in bearing and in tearing are 3425 kg, 4575 kg and 5025 kg respectively. If the load in the member is 35 tonnes, the number of rivets required, is
A. 10
B. 11
C. 12
D. 13
Answer : D

30. The minimum edge distance of a rivet line connecting two or more plates, is kept equal to 37 mm plus (where t is the thickness in mm of the thinner outside plate).
A. 2 t
B. 4 t
C. 6 t
D. 8 t
Answer : B

31. A tension member, if subjected to possible reversal of stress due to wind, the slenderness ratio of the member should not exceed
A. 180
B. 200
C. 300
D. 350
Answer : D

32. The critical load for a column of length I hinged at both ends and having flexural rigidity El, is given by
A. P_c = ?²EI/l²
B. P_c = ?EI/l²
C. P_c = ?EI/I²
D. None of these
Answer : A

33. The least permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
A. 150 t
B. 160 t
C. 170 t
D. 180 t
Answer : D

34. Long column is one
A. Which is more than 3 m long
B. Whose lateral dimension is less than 25 cm
C. Which is free at its top
D. Which has a ratio of effective length and least lateral dimension more than 15
Answer : D

35. 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

36. The Indian standard code which deals with steel structures, is
A. IS : 875
B. IS : 800
C. IS : 456
D. IS : 1893
Answer : B

37. For determination of allowable stress in axial compression, Indian Standard Institution has adopted
A. Euler's formula
B. Rankine formula
C. Perry Robertson formula
D. Secant formula
Answer : D

38. 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

39. The maximum tensile and compressive bending stress in extreme fibres of rolled I-sections and channels on the effective section, is
A. 1500 kg/cm²
B. 1420 kg/cm²
C. 1650 kg/cm²
D. 2285 kg/cm²
Answer : C

40. Pick up the correct statement from the following:
A. When the gauge distance is larger than the pitch, the failure of the section may occur in a zig-zag line
B. When the gauge distance is smaller than the pitch, the failure of the section may occur in a straight right angle section through the centre of rivet holes
C. When the gauge distance and pitch are both equal, the failure to the section becomes more likely as the diameter of the holes increases
D. All the above
Answer : D

41. Pick up the correct statement from the following:
A. The slenderness ratio of lacing bars for compression members should not exceed 145
B. The minimum width of lacing bar connected with rivets of nominal diameter 16 mm, is kept 50 mm
C. The minimum thickness of a flat lacing bar is kept equal to onefortieh of its length between inner end rivets
D. All the above
Answer : D

42. 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

43. Assuming the values of maximum deviation ?P and ?E to be 25% of the computed value of P and E respectively, the minimum value of the factor of safety is
A. 1.00
B. 0.67
C. 1.67
D. 2.67
Answer : C

44. By providing sufficient edge distance, which of the following failures of riveted joint can be avoided?
A. Tension failure of the plate
B. Shear failure of the rivet
C. Shear failure of the plate
D. Crushing failure of the rivet
Answer : C

45. Rolled steel beams are:
A. Mainly used to resist bending stress
B. Used as independent sections to resist compressive stress
C. Used as independent sections to resist tensile stress
D. All the above
Answer : D

46. The size of a butt weld is specified by the effective throat thickness which in the case of incomplete penetration, is taken as
A. ½ of the thickness of thicker part
B. ¾ of the thickness of thicker part
C. ¾ of the thickness of thinner part
D. 7/8 of the thickness of thinner part
Answer : D

47. Effective length of a column effectively held in position and restrained in direction at both ends, is
A. L
B. 0.67 L
C. 0.85 L
D. 1.5 L
Answer : B

48. If W and L are the total superimposed load and the span of a plate girder in metres, the approximate self weight (W) of the girder, is taken as
A. M = WL/100
B. M = WL/200
C. M = WL/300
D. M = WL/400
Answer : C

49. Which of the following sections should preferably be used at places where torsion occurs?
A. Angle section
B. Channel section
C. Box type section
D. Any of the above
Answer : C

50. If L is the overall length of a combined footing having A as its area, d being the distance between the centre of gravity of the base and centre of the base, the larger width b is
A. (A/L) + (3Ad/L²)
B. (A/L) + (6Ad/L²)
C. (A/L) - (6Ad/L²)
D. (A/L) - (3Ad/L²)
Answer : B