Steel Structures - Compression Members

1. Factor of safety adopted by IS: 800 - 1984 while arriving at the permissible stress in axial compression is
(a) 2.00
(b) 1.00
(c) 1.67
(d) 1.50 (GATE 1997)

2. In the design of compression member, the section should be proportioned to have the ___ radius of gyration.
(a) smallest
(b) largest
(c) average
(d) none of these

3. For which of the following shapes radius of gyration is largest for a given cross sectional area?
(a) square
(b) rectangle
(c) circular
(d) triangular

4. For compression members, I sections are most suited because
(a) their radius of gyration is largest for a given cross sectional area
(c) both (a) and (b)
(d) neither (a) nor (b)

5. In chimneys, the allowable axial compression reduces with the ratio d/t (i.e. diameter/plate thickness) and not with l/r as in columns. This is to recognize the
(a) hoop compressive strain produced by axial compression
(b) temperature gradient caused by hot gases
(c) shell buckling
(d) axial strain produced by hoop tension (IES 1999)

6. Which of the following is the most critical set of considerations in the design of rolled steel columns carrying axial loads?
(a) per cent elongation at yield and the net cross sectional area
(b) critical bending strength and axial yield strength of the material
(c) buckling strength based on the net area of the section and percent elongation at ultimate load
(d) compressive strength based on slenderness ratio and gross cross-sectional area of the member (IES 1999)

7. A single angle strut ISA 50 x 50 x 6 mm of a roof truss is 1.06 mm long. Maximum radius of gyration will be (given = 0.96 cm).
(a) 110.42
(b) 120
(c) 180
(d) 250

8. The buckling load in a steel column is
(a) related to length
(b) directly proportional to slenderness ratio
(c) inversely proportional to slenderness ratio
(d) non linearly related with slenderness ratio (IES 1992)

9. Different components of a built up compression member are connected together by
(a) lacing
(b) battening
(c) both (a) and (b)
(d) none of these

10. Lacing is generally preferred if compression member is subject to
(c) shear stresses
(d) tensile stresses