26. The sum of normal stresses is
a) constant
b) variable
c) dependent on the planes
d) none of the above
Ans: a
27. The radius of Mohr’s circle for two equal unlike principal stresses of magnitude p is
a) p
b) p/2
c) zero
d) none of the above
Ans: a
28. Shear stress on principal planes is
a) zero
b) maximum
c) minimum
d) none of the above
Ans: a
29. The state of pure shear stress is produced by
a) tension in one direction and equal compression in perpendicular direction
b) equal tension in two directions at right angles
c) equal compression in two directions at right angles
d) none of the above
Ans: a
30. According to Rankine’s hypothesis, the criterion of failure of a brittle material is
a) maximum principal stress
b) maximum shear stress
c) maximum strain energy
d) maximum shear strain energy
Ans: a
31. Maximum bending moment in a beam occurs where
a) deflection is zero
b) shear force is maximum
c) shear force is minimum
d) shear force changes sign
Ans: d
32. Rate of change of bending moment is equal to
a) shear force
b) deflection
c) slope
d) rate of loading
Ans: d
33. The diagram showing the variation of axial load along the span is called
a) shear force diagram
b) bending moment diagram
c) thrust diagram
d) influence line diagram
Ans: a
34. The difference in ordinate of the shear curve between any two sections is equal to the area under
a) load curve between these two sections
b) shear curve between these two sections
c) bending moment curve between these two sections
d) load curve between these two sections plus concentrated loads applied between the sections
Ans: d
35. The variation of the bending moment in the portion of a beam carrying linearly varying load is
a) linear
b) parabolic
c) cubic
d) constant
Ans: c
36. The maximum bending moment due to a moving load on a fixed ended beam occurs
a) at a support
b) always at the midspan
c) under the load only
d) none of the above
Ans: a
37. A cantilever beam AB of length 1 carries a concentrated load W at its midspan C. If the free end B is supported on a rigid prop, then there is a point of contraflexure
a) between A and C
b) between C and B
c) one between A and C and other between C and B
d) nowhere in the beam
Ans: a
38. A prismatic beam fixed at both ends carries a uniformly distributed load. The ratio of bending moment at the supports to the bending moment at mid-span is
a) 0.5
b) 1.0
c) 1.5
d) 2.0
Ans: d
39. A beam of overall length 1 with equal overhangs on both sides carries a uniformly distributed load over the entire length. To have numerically equal bending moments at centre of the beam and at supports, the distance between the supports should be
a) 0.2771
b) 0.403 1
c) 0.5861
d) 0.7071
Ans: c
40. A prismatic beam of length 1 and fixed at both ends carries a uniformly distributed load. The distance of points of contraflexure from either end is
a) 0.2071
b) 0.2111
c) 0.2771
d) 0.251
Ans: b
41. A simply supported beam of length 1 carries a load varying uniformly from zero at left end to maximum at right end. The maximum bending moment occurs at a distance of
a) 1/V3 from left end
b) 1/3 from left end
c) 1/V3 from right end
d) 1/3 from right end
Ans: a
42. A portion of a beam between two sections is said to be in pure bending when there is
a) constant bending moment and zero shear force
b) constant shear force and zero bending moment
c) constant bending moment and constant shear force
d) none of the above
Ans: a
43. The ratio of width to depth of a strongest beam that can be cut out of a cylindrical log of wood is
a) 1/2
b) 1/V2
c) 1/3
d) 2/3
Ans: b
44. Of the several prismatic beams of equal lengths, the strongest in flexure is the one having maximum
a) moment of inertia
b) section modulus
c) tensile strength
d) area of cross-section
Ans: b
45. Of the two prismatic beams of same material, length and flexural strength, one is circular and other is square in cross-section. The ratio of weights of circular and square beams is
a) 1.118
b) 1.342
c) 1.000
d) 0.793
Ans: a
46. A flitched beam consists of a wooden joist 150 mm wide and 300 mm deep strengthened by steel plates 10 mm thick and 300 mm deep one on either side of the joist. If modulus of elasticity of steel is 20 times that of wood, then the width of equivalent wooden section will be
a) 150 mm
b) 350 mm
c) 500 mm
d) 550 mm
Ans: d
47. A beam of rectangular cross-section is 100 mm wide and 200 mm deep. If the section is subjected to a shear force of 20 kN, then the maximum shear stress in the section is
a) 1 N/mm2
b) 1.125 N/mm2
c) 1.33 N/mm2
d) 1.5 N/mm2
Ans: d
48. A beam of square cross-section with side 100 mm is placed with one diagonal vertical. If the shear force acting on the section is 10 kN, the maximum shear stress is
a) 1 N/mm2
b) 1.125 N/mm2
c) 2 N/mm2
d) 2.25 N/mm2
Ans: b
49. A prismatic bar when subjected to pure bending assumes the shape of
a) catenary
b) cubic parabola
c) quadratic parabola
d) arc of a circle
Ans: d
50. A beam of triangular cross section is placed with its base horizontal. The maximum shear stress intensity in the section will be
a) at the neutral axis
b) at the base
c) above the neutral axis
d) below the neutral axis
Ans: c