#### Multiple Questions and Answers on Design of Steel Structures

**01. 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: Option C **

**02. 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: Option C **

**03. 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: Option D **

**04. 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: Option C**

** 05. Other conditions being same, the load factor in indeterminate structures is **

(A) Equal to load factor in determinate structures

(B) More than the load factor in determinate structures

(C) Less than the load factor in determinate structures

(D) Unpredictable

** Answer: Option B**

** 06. 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: Option A **

**07. 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: Option B **

**08. 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: Option C **

**09. 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: Option C **

**10. The elastic strain for steel is about **

(A) 1/12 of strain at the initiation of strain hardening and about 1/120 of maximum strain

(B) 1/2 of strain at the initiation of strain hardening and about 1/12 of maximum strain

(C) 1/12 of strain at the initiation of strain hardening and 1/200 of maximum strain (D) 1/24 of strain at the initiation of strain hardening and about 1/200 of maximum strain

**Answer: Option C **

**11. In the virtual work method, the virtual quantity is **

(A) Displacement

(B) Load

(C) Slope

(D) Moment

**Answer: Option A **

**12. 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: Option C**

** 13. 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: Option A**

** 14. The maximum permissible span of asbestos cement sheets is **

(A) 650 mm

(B) 810 mm

(C) 1250 mm

(D) 1680 mm

** Answer: Option D**

** 15. Lacing bars in a steel column should be designed to resist **

(A) Bending moment due to 2.5% of the column load

(B) Shear force due to 2.5% of the column load

(C) 2.5% of the column load

(D) Both (A) and (B)

**Answer: Option B **

**16. 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: Option B **

**17. 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: Option C**

** 18. Shear buckling of web in a plate girder is prevented by using**

(A) Vertical intermediate stiffener

(B) Horizontal stiffener at neutral axis

(C) Bearing stiffener

(D) None of the above

**Answer: Option A **

**19. The most commonly used sections in lateral system to carry shear force in built up columns, are **

(A) Rolled steel flats

(B) Rolled angles

(C) Rolled channels

(D) All the above

**Answer: Option D **

**20. The stress in the wall of a thin cylinder subjected to internal pressure, is**

(A) Hoop compression

(B) Shear

(C) Torsional shear

(D) Hoop tension

**Answer: Option D **

**21. 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: Option C **

**22. For eccentrically loaded columns, the bending factor is**

(A) Cross-sectional area of column/Radius of gyration

(B) Radius of gyration/Cross-sectional area of column

(C) Cross-sectional area of column/Section modulus of the section

(D) Section modulus of the section/Cross-sectional area of column

**Answer: Option C **

**23. The net area of round bars to resist the tension, is the area of cross section at**

(A) Mid-section

(B) Root of the thread

(C) Difference of (a) and (b)

(D) None of these

**Answer: Option B **

**24. The bracing between two columns of a steel tank will be designed to resist**

(A) Horizontal shear due to wind or earthquake only

(B) Horizontal, shear due to wind or earthquake + 2.5% of column loads

(C) Column loads + 2.5% of horizontal shear due to wind or earthquake

(D) Column loads + full horizontal shear due to wind or earthquake

**Answer: Option B **

**25. A column splice is used to increase **

(A) Length of the column

(B) Strength of the column

(C) Cross-sectional area of the column

(D) None of these

**Answer: Option A **

**26. 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: Option D **

**27. The bracing provided in the plane of end posts is called**

(A) Sway bracing

(B) Portal bracing

(C) Top lateral bracing

(D) Bottom lateral bracing

**Answer: Option B **

**28. In a built up beam actual bending compressive stress fbc is given by (when y1 is the distance of the edge of the beam from the neutral axis). **

(A) fbc = (M/Ixx) × y₁

(B) fbc = (Ixx/M) × y₁

(C) fbc = (Ixx/M) + y₁

(D) fbc = (M/Ixx) + y₁

**Answer: Option A**

** 29. If the thickness of a structural member is small as compared to its length and width, it is classified as **

(A) One dimensional

(B) Two dimensional

(C) Three dimensional

(D) None of these

**Answer: Option B **

**30. 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: Option B **

**31. Lug angle is **

(A) Used with single angle member

(B) Not used with double angle member

(C) Used with channel member

(D) All the above

**Answer: Option D **

**32.Compression members composed of two channels back-to-back and separated by a small distance are connected together by riveting so that the minimum slenderness ratio of each member between the connections, does not exceed**

(A) 40

(B) 50

(C) 60

(D) 70

** Answer: Option A **

**33. The connection of intermediate vertical stiffeners to the web, not subjected to external loads, shall be designed for a minimum shear force (kN/m) of **

(A) 75 t²/h

(B) 125 t3/h²

(C) 125 t²/h

(D) 175 t²/h

Where, t = the web thickness in mm and h = the outstand of stiffener in mm

**Answer: Option C**

** 34. When the upper column does not provide full bearing area over lower column, the column splice is provided with the following assumption **

(A) Bearing plate is assumed as a short beam to transmit the axial load to the lower column section

(B) Axial load is assumed to be taken by flanges

(C) Load transmitted from the flanges of upper column and reactions from the flanges of lower columns are equal and form a couple

(D) All the above

**Answer: Option D**

** 35. For the economical design of a combined footing to support two equal column loads, the projections of beams in lower tier are kept such that bending moment under column is equal to**

(A) Bending moment at the centre of the beam

(B) Half the bending moment at the centre of the beam

(C) Twice the bending moment at the centre of the beam

(D) None of these

**Answer: Option A **

**36. The allowable shear stress in the web of mild steel beams decreases with**

(A) Decrease in h/t ratio

(B) Increase in h/t ratio

(C) Decrease in thickness

(D) Increase in height

Where ‘h’ is height and ‘t’ is thickness

**Answer: Option B **

**37. 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: Option A **

**38. 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: Option D **

**39. As compared to field rivets, the shop rivets are **

(A) Stronger

(B) Weaker

(C) Equally strong

(D) Any of the above

**Answer: Option A **

**40. 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: Option C **

**41. 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: Option C**

** 42. When the bolts are subjected to reversal of stresses, the most suitable type of bolt is**

(A) Black bolt

(B) Ordinary unfinished bolt

(C) Turned and fitted bolt

(D) High strength bolt

** Answer: Option D **

**43. Factor of safety is the ratio of**

(A) Yield stress to working stress

(B) Tensile stress to working stress

(C) Compressive stress to working stress

(D) Bearing stress to working stress

** Answer: Option A**

** 44. 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: Option D **

**45. The best arrangement to provide unified behaviour in built up steel columns is by **

(A) Lacing

(B) Battening

(C) Tie plates

(D) Perforated cover plates

**Answer: Option A**

** 46. The ratio of shearing stress to shearing strain within elastic limit, is known as**

(A) Modulus of elasticity

(B) Shear modulus of elasticity

(C) Bulk modulus of elasticity

(D) Tangent modulus of elasticity

**Answer: Option B**

** 47. In a built up section carrying a tensile force, the flanges of two channels are turned outward**

(A) To simplify the transverse connections

(B) To minimise lacing

(C) To have greater lateral rigidity

(D) All the above

**Answer: Option C**

** 48. The overlap of batten plates with the main members in welded connections should be more than **

(A) 3 t

(B) 4 t

(C) 6 t

(D) 8 t

Where ‘t’ = thickness of the batten plate

**Answer: Option B **

**49. A fillet weld may be termed as **

(A) Mitre weld

(B) Concave weld

(C) Convex weld

(D) All the above

** Answer: Option D **

**50. Modified moment of inertia of sections with a single web, is equal to moment of inertia of the section about Y-Y axis at the point of maximum bending moment and is multiplied by the ratio of**

(A) Area of compression flange at the minimum bending moment to the corresponding area at the point of maximum bending moment

(B) Area of tension flange at the minimum bending moment of the corresponding area at the point of maximum bending moment

(C) Total area of flanges at the maximum bending moment to the corresponding area at the point of maximum bending moment

(D) None of these

**Answer: Option C**