Stresses in Beams

 

TOTAL MECHANICAL ENGINEERING

 Section 

Simple Stress and Strain.

Principle Stress, Strain and Strain energy.

Stresses in Beam.

Deflection of beam.

Torsion and Axially Loaded Column.

Stresses in Beams

Quiz

 

1. The bending moment at a point on a beam is the algebraic _ of all
   the moments on either side of the point.
   1.   sum
   2.   difference
2. The point of contra flexure is a point where
   1.   shear force changes sign
   2.   bending moment changes sign
   3.   shear force is maximum
   4.   bending moment is maximum
3. When shear force at a point is zero, then bending moment is______ at that point.
   1.   zero
   2.   minimum
   3.   maximum
   4.   infinity
4. The limit of eccentricity is based upon no tension condition.
   1.   True
   2.   False
5. If the depth is kept constant for a beam of uniform strength, then its width will
   vary in proportional to (where M = Bending moment)
   1.   M
   2.   M5
   3.   M2
   4.   M3
6. A concentrated load is one which
   1.   acts at a point on a beam
   2.   spreads non-uniformly over the whole length of a beam
   3.   spreads uniformly over the whole length of a beam
   4.   varies uniformly over the whole length of a beam
7. A load which is spread over a beam in such a manner that it varies uniformly over the whole length of abeam is called uniformly
   1.   distributed
   2.   varying
8. The shear force at apoint on a beam is the algebraic side of the point.
   1.   sum
   2.   difference
9. The point of contra flexure occurs in
   1.   cantilever beams load. of all the forces on either
   2.   simply supported beams
   3.   overhanging beams
   4.   fixed beams
10. The shear force of a simply supported beam carrying a central point load changes sign at its midpoint.
    1.   Correct
    2.   Incorrect
11. A beam of uniform strength has
    1.   same cross-section throughout the beam
    2.   same bending stress at every section
    3.   same bending moment at every section
    4.   same shear stress at every section
12. The bending moment of a cantilever beam of length l and carrying a gradually
    varying load from zero at free end and w per unit length at the fixed end is______ at the fixed end.
    1.   wl/2
    2.   wl
    3.   wl2/2
    4.   wl2/6
13. An overhanging beam must overhang on both sides.
    1.   Correct
    2.   Incorrect
14. In a beam where shear force changes sign, the bending moment will be
    1.   zero
    2.   minimum
    3.   maximum
    4.   infinity
15. The shear force diagram for a simply supported beam carrying a uniformly
    distributed load of w per unit length, consists of
    1.   one right angled triangle
    2.   two right angled triangles
    3.   one equilateral triangle
    4.   one equilateral triangle
16. Which of the following statement is correct?
    1.   A continuous beam has only two supports at the ends.
    2.   A uniformly distributed load spreads uniformly over the whole length of a beam.
    3.   The bending moment is maximum where shear force is maximum.
    4.   The maximum bending moment of a simply supported beam of length l with a central point load W is Wl/8.
17. When there is no increase or decrease in shear force between two points, it
    indicates that there is no change in the bending moment between these points.
    1.   True
    2.   False
18. When a beam is subjected to a bending moment, the strain in a layer is_________ the distance from
    1.   equal to
    2.   directly proportional to
    3.   inversely proportional to
    4.   independent of
19. The shear force diagram fora cantilever beam of length l and carrying a
    gradually varying load from zero at free end and w per unit length at the fixed
    end is a
    1.   horizontal straight line
    2.   vertical straight line
    3.   inclined line
    4.   parabolic curve
20. When a column is subjected to an eccentric load, the stress induced in the column will be
    1.   direct stress only
    2.   bending stress only
    3.   shear stress only
    4.   direct and bending stress both
21. A beam encastred at both the ends is called
    1.   simply supported beam
    2.   fixed beam
    3.   cantilever beam
    4.   continuous beam
22. The bending moment diagram for a simply supported beam carrying a
    uniformly distributed load of w per unit length, will be
    1.   a horizontal line
    2.   a vertical line
    3.   an inclined line
    4.   a parabolic curve
23. The bending moment at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per meter at the centre is wl/4.
    1.   Yes
    2.   No
24. A simply supported beam is one which is supported on more than two supports.
    1.   True
    2.   False
25. The maximum bending moment for a simply supported beam with a gradually
    varying load from zero at both ends and w per metre at the centre, lies at the centre of a beam.
    1.   Agree
    2.   Disagree
26. The maximum bending moment of a cantilever beam of length l and carrying a
    uniformly distributed load of w per unit length lies at the middle of its length.
    1.   True
    2.   False
27. If the magnitude of direct stress and bending stress is equal, then there will be zero stress at one of the extreme ends of a column.
    1.   Agree
    2.   Disagree
28. A beam which is fixed at one end and free at the other is called
    1.   simply supported beam
    2.   fixed beam
    3.   fixed beam
    4.   cantilever beam
29. The shear force in the centre of a simply supported beam carrying a uniformly
    distributed load of w per unit length, is
    1.   zero
    2.   wl2/2
    3.   wl2/4
    4.   wl2/8
30. A cantilever beam is one which is
    1.   fixed at both ends
    2.   fixed at one end and free at the other end
    3.   supported at its ends
    4.   supported on more than two supports
31. The neutral axis of a transverse section of a beam passes through the centre of gravity of the section and is
    1.   in the vertical plane
    2.   in the horizontal plane
    3.   in the same plane in which the beam bends
    4.   at right angle to the plane in which the beam bends
32. The maximum bending moment of a simply supported beam of span l and carrying a point load W at the centre of beam, is
    1.   Wl/4
    2.   Wl/2
    3.   Wl
    4.   Wl2/4
33. The shear force of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is____________ at the fixed end.
    1.   zero
    2.   wl/4
    3.   wl/2
    4.   wl
34. The bending moment at the free end of a cantilever beam is
    1.   zero
    2.   minimum
    3.   maximum
35. The bending moment of a cantilever beam of length l and carrying a uniformly
    distributed load of w per unit length is_____________ at the fixed end.
    1.   wl/4
    2.   wl/2
    3.   wl
    4.   wl2/2
36. The shear force of a cantilever beam of length l and carrying a gradually varying load from zero at the free end and w per unit length at the fixed end is____________ at the fixed end.
    1.   zero
    2.   wl/4
    3.   wl/2
    4.   wl
37. A continuous beam is one which is
    1.   fixed at both ends
    2.   fixed at one end and free at the other end
    3.   supported on more than two supports
    4.   extending beyond the supports
38. The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per meter at the centre, is
    1.   zero
    2.   wl/4
    3.   wl/2
    4.   wl2/2
39. When a load on the free end of a cantilever beam is increased, failure will occur
    1.   at the free end
    2.   at the free end
    3.   in the middle of the beam
    4.   at a distance 2l/3 from free end
40. In a simply supported beam carrying a uniformly distributed load w per unit length,the point of contra flexure
    1.   lies in the centre of the beam
    2.   lies at the ends of the beam
    3.   depends upon the length of beam
    4.   does not exist
41. A beam supported on more than two supports is called
    1.   simply supported beam
    2.   fixed beam
    3.   overhanging beam
    4.   continuous beam
42. The shear force at the ends of a simply supported beam carrying a uniformly
    distributed load of w per unit length is
    1.   zero at its both ends
    2.   wl at one end and - wl at the other end
    3.   wl/2 at one end and - wl/2 at the other end
    4.   wl2/2 at one end and - wl2/2 at the other end
43. The shear force of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is______ at the free end.
    1.   zero
    2.   wl/4
    3.   wl/2
    4.   wl
44. The limit of eccentricity for no tensile conditions for a column of circular section of diameter (d) is
    1.   d/4
    2.   d/8
    3.   d/12
    4.   d/16
45. The neutral axis of the cross-section a beam is that axis at which the bending stress is
    1.   zero
    2.   minimum
    3.   maximum
    4.   infinity
46. When a rectangular beam is loaded transversely, the maximum compressive
    stress is developed on the
    1.   top layer
    2.   bottom layer
    3.   neutral axis
    4.   every cross-section
47. The maximum stress produced in a bar of tapering section is at
    1.   smaller end
    2.   larger end
    3.   middle
    4.   anywhere
48. The bending stress in a beam is______ section modulus.
    1.   directly proportional to
    2.   inversely proportional to
49. In a simple bending theory, one of the assumption is that the material of the
    beam is isotropic. This assumption means that the
    1.   normal stress remains constant in all directions
    2.   normal stress varies linearly in the material
    3.   elastic constants are same in all the directions
    4.   elastic constants varies linearly in the material
50. The maximum shear stress of a beam of triangular section occurs above the
    neutral axis,
    1.   Correct
    2.   Incorrect
51. When a rectangular beam is loaded transversely, the zero stress is developed
    on the neutral axis.
    1.   True
    2.   False
52. When a cantilever beam is loaded at its free end, the maximum compressive stress shall develop at
    1.   bottom fibre
    2.   top fibre
    3.   neutral axis
    4.   centre of gravity
53. When the shear force diagram is a parabolic curve between two points, it
    indicates that there is a
    1.   point load at the two points
    2.   no loading between the two points
    3.   uniformly distributed load between the two points
    4.   uniformly varying load between the two points
54. Modulus of resilience is the proof resilience per unit volume of a material.
    1.   Correct
    2.   Incorrect
55. A beam of T-section is subjected to a shear force of F. The maximum shear force will occur at the
    1.   top of the section
    2.   bottom of the section
    3.   neutral axis of the section
    4.   junction of web and flange
56. Which of the following statement is wrong?
    1.   In the theory of simple bending, the assumption is that the plane sections before bending remains plane after bending.
    2.   In a beam subjected to bending moment, the strain is directly proportional to the distance from the neutral axis.
    3.   At the neutral axis of a beam, the bending stress is maximum.
    4.   The bending stress in a beam is inversely proportional to the section modulus.
57. The bending moment diagram for a cantilever beam of length l and carrying a
    gradually varying load from zero at the free end and w per unit length at the fixed end is a parabolic curve.
    1.   Agree
    2.   Disagree
58. The direct stress, across a principal plane, is known as principal stress.
    1.   Yes
    2.   No
59. At the neutral axis of a beam
    1.   the layers are subjected to maximum bending stress
    2.   the layers are subjected to minimum bending stress
    3.   the layers are subjected to compression
    4.   the layers do not undergo any strain
60. The line of intersection of the neutral layer with any normal cross-section of the beam is called neutral axis.
    1.   True
    2.   False