RRB NTPC - Design of Steel Structures 1000+ MCQ [Solved] PDF Download

1. If the loaded length of span in meters of a railway steel bridge carrying a single track is 6 m, then impact factor is taken as
A. 0
B. 0.5
C. Between 0.5 and 1.0
D. 1.0
Answer : C

2. The effective length of a fillet weld should not be less than
A. Two times the weld size
B. Four times the weld size
C. Six times the weld size
D. Weld size
Answer : B

3. The critical stress on a column for elastic buckling given by Euler's formula, is
A. f_c = ?²E/(I/r)²
B. f_c = (I/r)²/ ?E
C. f_c = (I/r)/ ?E
D. f_c = ?²E/(I/r)
Answer : A

4. 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

5. The maximum permissible slenderness ratio of a member carrying loads resulting from wind, is
A. 180
B. 200
C. 250
D. 300
Answer : C

6. The channels get twisted symmetrically with regard to its axis
A. Parallel to flanges
B. Parallel to web
C. Perpendicular to flanges
D. Perpendicular to web
Answer : B

7. The strength of a riveted lap joint is equal to its
A. Shearing strength
B. Bearing strength
C. Tearing strength
D. Least of (a), (b) and (c)
Answer : D

8. The minimum width B of a solid casing for a cased beam, is equal to
A. B = b + 25 mm
B. B = b + 50 mm
C. B = b + 75 mm
D. B = b + 100 mm
Answer : D

9. 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

10. The maximum slenderness ratio of a steel column, the design of which is governed by wind or seismic forces is
A. 150
B. 180
C. 250
D. 350
Answer : C

11. Cold driven rivets range from
A. 6 to 10 mm in diameter
B. 10 to 16 mm in diameter
C. 12 to 22 mm in diameter
D. 22 to 32 mm in diameter
Answer : C

12. If f is the maximum allowable bending stress in a tension member whose radius of gyration is r and depth is 2y, the required cross sectional area A is given by
A. A = My/fr²
B. A = My²/fr²
C. A = My/fr
D. A = My/f²r²
Answer : A

13. 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

14. 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

15. When the axis of load lies in the plane of rivet group, then the most heavily loaded rivet will be the one which (Where, Fa is the load shared by each rivet due to axial load and Fm is the shearing load due to moment in any rivet.)
A. Is at the maximum distance from CG of the rivet group
B. Is at the minimum distance from CG of the rivet group
C. Gives the maximum angle between the two forces Fa and Fm
D. Gives the minimum angle between the two forces Fa and Fm
Answer : D

16. Generally the purlins are placed at the panel points so as to avoid
A. Axial force in rafter
B. Shear force in rafter
C. Deflection of rafter
D. Bending moment in rafter
Answer : D

17. 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

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

20. In double lacing, the thickness t of flat lacing is
A. t < 1/40 th length between inner end rivets
B. t < 1/50 th length between inner end rivets
C. t < 1/60 th length between inner end rivets
D. t < 1/70 th length between inner end rivets
Answer : C

21. When a tension member is made of four angles with a plate as a web, the allowance for holes is mad as
A. Two holes for each angle and one hole for the web
B. One hole for each angle and one hole for the web
C. One hole for each angle and two holes for the web
D. Two holes for each angle and two holes for the web
Answer : C

22. According to IS Specifications, the maximum pitch of rivets in compression is
A. Lesser of 200 mm and 12 t
B. Lesser of 200 mm and 16 t
C. Lesser of 300 mm and 32 t
D. Lesser of 3 00 mm and 24 t Where t is thickness of thinnest outside plate or angle
Answer : A

23. An axial loaded column is supported on a slab base whose projection is 8 cm. If the intensity of pressure from concrete is 40 kg/cm² and allowable bending stress in slab base is 1890 kg/cm², the thickness (t) of the slab base, is
A. t = ?(21/64)
B. t = ?(64/21)
C. t = 21/64
D. t = 64/21
Answer : B

24. 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

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

26. The safe working pressure for a spherical vessel 1.5 m diameter and having 1.5 cm thick wall not to exceed tensile stress 50kg/cm², is
A. 16 kg/cm²
B. 18 kg/cm²
C. 20 kg/cm²
D. 22 kg/cm²
Answer : C

27. The strength of ISA 125 = 75 × 10 mm used as a tie member with its longer leg connected at the ends by 27 mm diameter rivets, is
A. 26,000 kg
B. 26,025 kg
C. 26,050 kg
D. 26,075 kg
Answer : D

28. If the area of cross-section of a single angle discontinuous strut is 30 cm2 and allowable working stress corresponding to its slenderness ratio is 625 kg/cm², the safe load carrying capacity of the member, is
A. 10 tonnes
B. 12 tonnes
C. 15 tonnes
D. 18 tonnes
Answer : C

29. Water pressure in a 80 cm water main is 10 kg/cm². The minimum thickness of the metal required for the water main, not to be stressed more than 200 kg/cm², is
A. 1 cm
B. 1.5 cm
C. 2 cm
D. 2.5 cm
Answer : C

30. For double angles carrying tension, placed back to back and connected to either side of the gusset plate, the sectional area of the section, is equal to cross sectional area of
A. The section
B. The section plus area of rivet holes
C. The section minus area of rivet holes
D. The section multiplied by the area of the rivet hole
Answer : C

31. Live load
A. Varies in magnitude
B. Varies in position
C. Is expressed as uniformly distributed load
D. All the above
Answer : D

32. 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

33. 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

34. Net sectional area of a tension member, is equal to its gross section area
A. Plus the area of the rivet holes
B. Divided by the area of rivet holes
C. Multiplied by the area of the rivet holes
D. None of these
Answer : D

35. A fillet weld whose axis is parallel to the direction of the applied load, is known as
A. Diagonal filler weld
B. End fillet weld
C. Side fillet weld
D. All the above
Answer : C

36. 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

37. Gantry girders are designed to resist
A. Lateral loads
B. Longitudinal loads and vertical loads
C. Lateral, longitudinal and vertical loads
D. Lateral and longitudinal loads
Answer : C

38. The beam outside a wall upto floor level above it, is known as
A. Rafter
B. Purlin
C. Spandrel beam
D. Lintel
Answer : C

39. The equivalent axial tensile load Pe, which produces an average axial tensile stress in the section equivalent to the combined stress due to axial tension P and bending M, at the extreme fibre of the section, is given by (where Z is the section modulus of the section).
A. Pe = P + MA/Z
B. Pe = P - MA/Z
C. Pe = P - Z/MA
D. Pe = P + Z/MA
Answer : A

40. The side thrust T on the tie rods provided at the end beam of jack arch of rise R, is calculated from the formula
A. T = WL/4R
B. T = WR/8L
C. T = WL/8R
D. T = WL/2R
Answer : C

41.If the moment of inertia of a section about its axis is I and its effective sectional area is A, its radius of gyration r about the axis, is
A. r = I/A
B. r = ?(I/A)
C. r = ?(I/A)
D. r = ?(A/I)
Answer : B

42. The permissible stress to which a structural member can be subjected to, is known as
A. Bearing stress
B. Working stress
C. Tensile stress
D. Compressive stress
Answer : B

43. 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

44. The allowable stress in axial tension for rolled I-sections and channels, is taken as
A. 1420 kg/cm²
B. 1500 kg/cm²
C. 2125 kg/cm²
D. 1810 kg/cm²
Answer : B

45. 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

46. 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

47. 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

48. The heaviest I-section for same depth is
A. ISMB
B. ISLB
C. ISHB
D. ISWB
Answer : C

49. 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

50. The greatest gauge of long rivets should not exceed (where d is the diameter of the holes).
A. 2 d
B. 4 d
C. 6 d
D. 8 d
Answer : D