1. Members used in bridges parallel to traffic are called
a) spandrel
b) stringers
c) purlin
d) joist
Explanation: Stringers are members used in bridges parallel to traffic to carry the deck slab. They will be connected by transverse floor beams.
2. Which of the following statement is correct?
a) beams are termed as fixed beams when end condition do not carry end moments
b) beams are termed as simply supported beams when ends are rigidly connected to other members
c) beams are termed as fixed beams when ends are rigidly connected to other members
d) beams are termed as continuous beams when they do not extend across more than two support
Explanation: Beams may be termed as simply supported beams when end condition do not carry any end moments from any continuity developed by connection. A beam is called continuous beam when it extends continuously across more than two supports. A fixed beam has its ends rigidly connected to other members, so that moments can be carried across the connection.
3. Complex stresses may occur when
a) loads are inclined to principal axes
b) loads are along principal axes
c) symmetrical section are used
d) small values of shear and bending moment occur at section
Explanation: Complex stresses may arise when loads are inclined to principal axes, when unsymmetrical sections are used or when large values of shear and bending moment occur at section.
4. Simple bending takes place if
a) loading passes above shear centre for single symmetric open section
b) loading passes below shear centre for single symmetric open section
c) loading plane coincides with one of the principal planes of doubly symmetric section
d) loading plane do not coincide with one of the principal planes of doubly symmetric section
Explanation: Simple bending takes place if loading plane coincides with one of the principal planes of doubly symmetric section such as I-section or in case of singly symmetric open section such as channel section, the loading passes through shear centre and is parallel to the principal plane. Unsymmetrical bending occurs if loading does not pass through shear centre.
5. Which of the following buckling does not occur in beam?
a) lateral buckling of whole beam
b) local buckling of web
c) local buckling of flanges
d) longitudinal buckling of web
Explanation: Buckling may take place in many ways : (i) lateral buckling of whole beam between supports, (ii) local buckling of flanges, (iii) longitudinal buckling of web and buckling in depth direction under concentrated loads.
6. A beam section is provided on the basis of
(i) section modulus, (ii) deflection, (iii) shear
a) i, ii
b) ii, iii
c) i, iii
d) i, ii and iii
Explanation: A beam section is provided on the basis of (i) section modulus, (ii) deflection, (iii) shear. The beam should be economical with furnishing required modulus of section.
7. Which of the following is not correct?
a) Angles and T section are strong in bending
b) Channels can be used only for light loads
c) I sections are most efficient and economical shapes
d) I section with cover plates are provided when large section modulus is required
Explanation: Angles and T section are weak in bending. Channels can be used only for light loads. I sections (rolled and built-up) are most efficient and economical shapes. I section with cover plates are provided when large section modulus is required. Generally, ISLB or ISMB are provided in such cases.
8. Local buckling can be prevented by
a) limiting width-thickness ratio
b) increasing width-thickness ratio
c) changing material
d) changing load on member
Explanation: Local buckling of compression members of beam causes loss of integrity of beam cross section. It is a function of width-thickness ratio and can be prevented by limiting width-thickness ratio.
9. Which of the following is true?
a) in case of rolled section, less thickness of plate is adopted to prevent local buckling
b) for built-up section and cold formed section, longitudinal stiffeners are not provided to reduce width to smaller sizes
c) local buckling cannot be prevented by limiting width-thickness ratio
d) in case of rolled section, high thickness of plate is adopted to prevent local buckling
Explanation: In case of rolled section, higher thickness of plate is adopted to prevent local buckling. Local buckling cannot be prevented by limiting width-thickness ratio. For built-up section and cold formed section, longitudinal stiffeners are provided to reduce width to smaller sizes.
10. Which of the following is not true?
a) only plastic section can be used in intermediate frames
b) slender sections are preferred in hot rolled structural steelwork
c) compact sections can be used in simply supported beams
d) semi-compact sections can be used for elastic designs
Explanation: Only plastic section can be used in intermediate frames which form collapse mechanism. Compact sections can be used in simply supported beams which fail after reaching Mp at one section. Semi-compact sections can be used for elastic designs where section fails after reaching My at extreme fibres. Slender sections are not preferred in hot rolled structural steelwork, but they are extensively used in cold formed members.