1000+ Design of Steel Structures MCQ for IIFT [Solved]

1. The moment-curvature relation at a plastic hinge is
A. Linear
B. Parabolic
C. Constant moment for all curvatures
D. Constant curvature for all moments
Answer : C

2. Tongue plates are provided in a steel girder at
A. The upper flange
B. The lower flange
C. The upper end of the web
D. The upper and lower ends of the web
Answer : D

3. In a truss girder of a bridge, a diagonal consists of mild steel flat 4001.S.F. and carries a pull of 80 tonnes. If the gross-diameter of the rivet is 26 mm, the number of rivets required in the splice, is
A. 6
B. 7
C. 8
D. 9
Answer : C

4. The mechanism method of plastic analysis satisfies
A. Equilibrium and mechanism conditions
B. Equilibrium and plastic moment conditions
C. Mechanism and plastic moment conditions
D. Equilibrium condition only
Answer : A

5. According to IS : 800 - 71, the minimum thickness of a vertically stiffened web plate, shall not be less than
A. d/85
B. d/200
C. d/225
D. d/250
Answer : D

6. 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

7. 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

8. Secant formula for direct stress in compression, is applicable only for slenderness ratio upto
A. 120
B. 130
C. 140
D. 150
Answer : C

9. The portal bracing in a truss bridge is used to
A. Transfer load from top of end posts to bearings
B. Keep the rectangular shape of the bridge cross-section
C. Stiffen the structure laterally
D. Prevent the sides-way buckling of top chord
Answer : A

10. 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

11. As per ISI, rolled steel beam sections are classified into
A. Two series
B. Three series
C. Four series
D. Five series
Answer : D

12. The risk coefficient k, depends on
A. Mean probable design life of structures
B. Basic wind speed
C. Both (A) and (B)
D. None of the above
Answer : C

13. A 20 mm dia steel bar which is subjected to an axial tension of 2300 kg/cm² produces a strain of 0.004 cm. If Young's modulus of steel is 2.1 × kg/cm², the bar is
A. In the elastic range
B. In the plastic range
C. At yield point
D. None of these
Answer : A

14. For a cantilever beam of length L built-in at the support and restrained against torsion at the free end, the effective projecting length l is
A. l = 0.7 L
B. l = 0.75 L
C. l = 0.85 L
D. l = 0.5 L
Answer : B

15. The statical method of plastic analysis satisfies
A. Equilibrium and mechanism conditions
B. Equilibrium and plastic moment conditions
C. Mechanism and plastic moment conditions
D. Equilibrium condition only
Answer : B

16. If d is the distance between the flange angles of a plate girder, vertical stiffeners are provided at a distance not greater than
A. d but not less than 0.20 d
B. 1.25 d but not less than 0.33 d
C. 1.5 d but not less than 0.33 d
D. 2.0 d but not less than 0.50 d
Answer : B

17. The area A_p of cover plates in one flange of a built up beam, is given by
A. A_p = Z_reqr + Z_beam/h
B. A_p = Z_reqr + Z_beam/A
C. A_p = Z_reqr × Z_beam/h
D. A_p = Z_reqr - Z_beam/h
Answer : D

18. To keep the intensity of bearing pressure between the column base and concrete compressive and to vary from zero to 2P/BL, the ratio of the moment M to the axial load P should be
A. L/2
B. L/3
C. L/4
D. L/6
Answer : D

19. 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

20. Tacking rivets in tension members, are provided at a pitch in line not exceeding
A. 25 cm
B. 50 cm
C. 75 cm
D. 100 cm
Answer : D

21. If d is the distance between the flange angles,
A. Vertical stiffeners are provided in steel plate girders if the web is less than d/85
B. Vertical stiffeners are provided in high tensie steel plate girders if the web is less than d/175
C. Horizontal stiffeners are provided in steel plate girders if the web is less than d/200
D. All the above
Answer : D

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

23. Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
A. 16 times the thickness of outside plate
B. 24 times the thickness of outside plate
C. 32 times the thickness of outside plate
D. 36 times the thickness of outside plate
Answer : C

24. Rolled steel Tee-sections are used
A. As columns
B. With flat strips to connect plates in steel rectangular tanks
C. As built up sections to resist axial tension
D. None of these
Answer : B

25. 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

26. 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

27. 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

28. 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

29. Working shear stress on the gross area of a rivet as recommended by Indian Standards, is
A. 785 kg/cm²
B. 1025 kg/cm²
C. 2360 kg/cm²
D. None of these
Answer : B

30. According to I.S. : 800 - 1871, lacing bars resist transverse shear equal to
A. 1.0% of the axial load
B. 2.0% of the axial load
C. 2.5% of the axial load
D. 3.0% of the axial load
Answer : C

31. 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

32. The allowable stress in axial tension is generally kept less if thickness of the member is more than
A. 10 mm
B. 12 mm
C. 15 mm
D. 20 mm
Answer : D

33. Outstanding length of a compression member consisting of a channel, is measured as
A. Half of the nominal width
B. Nominal width of the section
C. From the edge to the first row of rivets
D. None of these
Answer : B

34. Design of a riveted joint is based on the assumption:
A. Bending stress in rivets is accounted for
B. Riveted hole is assumed to be completely filled by the rivet
C. Stress in the plate in not uniform
D. Friction between plates is taken into account
Answer : B

35. For a steel grillage footing to support two unequal column loads
A. Line of action of the resultant of two column loads, is made to coincide with the centre of gravity of the base of the footing
B. Trapezoidal shape is used for the base footing
C. Projections of beams on either side in lower tier are such that bending moments under columns are equal
D. All the above
Answer : D

36. The web crippling due to excessive bearing stress can be avoided by
A. Increasing the web thickness
B. Providing suitable stiffener
C. Increasing the length of the bearing plates
D. None of the above
Answer : C

37. 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

38. 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

39. The maximum slenderness ratio of a compression member carrying both dead and superimposed load is
A. 180
B. 200
C. 250
D. 350
Answer : A

40. 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

41. For a compression member with double angle section, which of the following section will give larger value of minimumradius of gyration?
A. Equal angles back to back
B. Unequal legged angles with long legs back to back
C. Unequal legged angles with short legs back to back
D. Both (B) and (C)
Answer : B

42. The forces acting on the web splice of a plate girder are
A. Axial forces
B. Shear and axial forces
C. Shear and bending forces
D. Axial and bending forces
Answer : C

43. Allowable working stress corresponding to the slenderness ratio of double angles placed back to back and connected to one side of a gusset plate, is reduced to
A. 50 %
B. 60 %
C. 70 %
D. 80 %
Answer : D

44. 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 onefortieth of its length between inner end rivets
D. All the above
Answer : D

45. 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

46. The thickness of the web of a mild steel plate girder is less than d/200. If only one horizontal stiffener is used, it is placed at
A. The neutral axis of the section
B. 2/3rd of the depth of the neutral axis from the compression flange
C. 2/5th of the depth of the neutral axis from the compression flange
D. 2/5th of the height of the neutral axis from tension flange
Answer : C

47. Bolts are most suitable to carry
A. Shear
B. Bending
C. Axial tension
D. Shear and bending
Answer : C

48. On eccentrically loaded columns, the equivalent axial load may be obtained by
A. Adding the axial load, eccentric load, the product of the bending moment due to eccentric load and the appropriate bending factor
B. Adding the axial load and eccentric load and subtracting the product of bending moment and appropriate bending factor
C. Dividing the sum of axial load and eccentric load by the product of the bending moment and appropriate bending factor
D. None of these
Answer : A

49. The rivets which are heated and then driven in the field, are known
A. Power driven shop rivets
B. Power driven field rivets
C. Hand driven rivets
D. Cold driven rivets
Answer : B

50. Battening is preferable when the (i) Column carries axial load only (ii) Space between the two main components is not very large (iii) Column is eccentrically loaded The correct answer is
A. Only (i)
B. Only (iii)
C. (i) and (ii)
D. (ii) and (iii)
Answer : C