Quiznetik

Strength of Materials | Set 9

1. In case of non-dilatent materials, the maximum value of Poisson's ratio is

Correct : A. 0.5

2. A self-supporting steel chimney transmits the lateral forces to the foundation by

Correct : C. cantilever action

3. The phenomenon under which the strain of a material varies under constant stress is known as

Correct : D. Creep

4. The strength of a riveted plate in tearing should be based on

Correct : B. the rivet hole diameter

5. The Erichsen cupping number of a sheet metal indicates its

Correct : B. Drawing quality

6. The limiting value of span to depth ratio will be least in case of

Correct : D. cantilever slabs

7. A load of 10,000 kg is applied to copper cylinder 20 cm long and 5 cm in diameter causes the length to increase by 4 mm and diameter to decrease by 0.4 mm. The Poisson's ratio for copper would be

Correct : B. 0.4

8. The allowable stresses for the design of steel chimney depend upon the ratio of

Correct : D. effective height to the radius of gyration

9. When a beam having square cross-section is loaded longitudinally, the shear stress develops

Correct : C. Equally on each fibre along horizontal plane

10. A solid circular shaft and a thin walled circular tube made of the same material and having the same weight are stressed in torsion to the same maximum shear stress. The ratio of the amounts of strain energy stored in the two shafts would be

Correct : D. ?

11. A bolt of nominal diameter 33 mm having a safe tensile stress of 100 N/mm2 can safely carry a load of

Correct : E. 60 kN

12. The number of elastic constants for a completely anisotropic elastic material which follows Hooke's law, is

Correct : B. 21

13. A masonry dam is liable to fail

Correct : E. Any of the above

14. The modulus of resilience in tension is nearly

Correct : D. 260 kJ/m3

15. The shape of the Kem area for a rectangular section is

Correct : D. Parallelogram

16. For any shaft the number of critical speed is

Correct : A. infinite

17. The ratio of Bulk modulus to shear modulus for Poisson's ratio of 0.25 will be

Correct : A. 5?3

18. In case of a hinged support, the reaction

Correct : C. Acts in a direction opposite to the resultant shear force at the support

19. The limiting values of Poisson's ratio are

Correct : D. ?1 and +0.5

20. The effect of arching a beam is to

Correct : C. reduce the bending moment throughout

21. A beam supported at more than two places is known as

Correct : C. Continuous beam

22. A spring steel ribbon 3.2 mm wide, 0.5 mm thick is wound on a 500 mm diameter cylinder. If E = 2 x 105 N/mm2, the maximum stress in the steel will be

Correct : B. 200 N/mm2

23. In a universal testing machine during the testing of a specimen of original cross-sectional area 1 cm2 the maximum load appliied was 7.5 tonnes and neck area 0.6 sq. cm. The ultimate tensile strength of the specimen is

Correct : C. 7.5 tonnes/cm2

24. It is desired to punch a hole of 20 mm diameter in a plate 20 mm think. If the shear stress of mild steel is 30 kg/mm2, the force necessary for punching would be approximately in the range

Correct : D. 35 - 40 tonnes

25. A spherical pressure vessel is made of thin magnesium plate 0.25 cm thick. The main diameter of the sphere is 600 cm and allowable stress in tension is 900 kg/cm2. The safe internal gas pressure for the vessel would be

Correct : E. 1.5 kg/cm2

26. Materials exhibiting time bound behaviour are known as

Correct : B. Visco elastic

27. The shear stress when a circular shaft subjected to torsion is

Correct : C. maximum, minimum

28. The deflection of a beam may be reduced by

Correct : C. providing greater end restrains

29. The safe working pressure for a spherical vessel 1.5 m diameter and 1.5 cm wall thickness with limiting tensile stress of 450 kg/cm2 would be

Correct : A. 18 kg/cm2

30. For a shear force to be uniform throughout the span of a simply supported beam, it should be subjected to

Correct : A. a couple at mid span

31. A cylindrical section having no joint is known as

Correct : D. Seamless section

32. Poisson's ratio for cast iron is

Correct : C. 0.27

33. A beam of uniform strength is one in which

Correct : A. The bending stress is same at every section

34. A material which undergoes no deformation till its yield point is reached and then it flows at a constant stress is known as

Correct : B. Rigid-plastic

35. The neutral axis of beam

Correct : C. Has tensile stress on one side and compressive stress on the other

36. For which of the following diameters a seam-less pipe of 3 mm wall thickness will be considered as a thin walled cylinder?

Correct : A. 30 mm

37. All elastic materials

Correct : A. Elongate on the application of load

38. The heaviest I section for the same depth is

Correct : C. ISHB

39. When a no. of loads rest upon a beam, the deflection at any point is equal to the sum of the deflections at this point due to each of the loads taken separately. This is according to

Correct : E. Max's well theorem

40. A form factor is introduced in the design of compressive members to represent the effect of

Correct : A. local buckling

41. As compared to the Brinell hardness lest, the Rockwell method

Correct : A. makes a thinner indentation

42. Two cantilever beams are of equal length. One carries a uniformly distributed load and other carries same load but concentrated at the free end. The ratio of maximum deflection is

Correct : E. 5?6

43. In a three-hinged beam, the bending moment will be zero at

Correct : D. the crown

44. Arching of a beam results in

Correct : B. reduced bending moment throughout

45. A dead load is

Correct : D. One that remains constant.

46. In the simple bending theory one of the assumptions usually made is that the plane sections before bending remain plane after bending. This assumption implies that

Correct : E. Strain is proportional to the distance from the neutral axis

47. Along the principal plane subjected to maximum principal shear

Correct : C. No shear stress acts

48. If the value of Young's modulus of elasticity for a material is zero, it implies that the material

Correct : C. incompressible

49. A steel shaft 6 mm in diameter turns at 10,000 r.p.m. the safe working stress in shear is 350 kg/cm2. The maximum power that such a shaft may develop is approximately

Correct : A. 2

50. The area around the centre of gravity of a cross-section within which any load applied will produce stress of only one sign throughout the entire cross-section, is known as

Correct : C. Kern

51. In case of thin walled cylinders the ratio of longitudinal stress to shear stress is

Correct : A. 2

52. A live load is one that

Correct : A. Varies continuously

53. Within elastic limits the greatest amount of strain energy per unit volume that a material can absorb is known as

Correct : D. Proof resilience

54. The deformation of a steel bar under its own weight as compared to the deformation caused by a direct load equal to the weight of the shaft will be

Correct : D. Half

55. Two shafts of the same material are subjected to the same torque. If the first shaft is of solid circular section and the second shaft is of hollow section whose internal diameter is 2/3 of the outside diameter, the ratio of weights of hollow shaft to solid shaft would be

Correct : C. Between 0.5 to 0.99

56. A solid cube is subjected to equal normal forces of the same type on all its faces. The ratio volumetric strain/liner strain in any of the three xes will be

Correct : A. 3

57. With a punch for which the maximum crushing stress is 4 times the maximum shearing stress of the plate, the biggest hole that can be punched in the plate would be of diameter equal to

Correct : B. Thickness of plate

58. A sheet metal 2 mm thick having a shear strength of 40 kg/cm2 is to receive a punch hole of 35 mm diameter. The force required to make the punching will be

Correct : B. 88 kg

59. The numerical value of Young's modulus of elasticity in ascending order for glass, aluminium, copper, wrought iron and tungsten are given by

Correct : A. Glass, aluminium, copper, wrought, iron, tungsten

60. Elasticity is the property of the material due to which it can be

Correct : E. None of the above

61. An underground pipeline is laid in spring at 35?C. If the pipe is unable to contract, during winter when temperature drops to 5?C, the pipe will be under

Correct : D. tensile stress

62. The maximum bending moment due to a moving load on a fixed ended beam occurs

Correct : D. at a support

63. The stress strain curve for a glass rod during tensile test would exhibit

Correct : C. A sudden break

64. The ratio of the area under the bending moment diagram between any two points along a beam to the flexural rigidity EI gives the change to the following parameter between the two points

Correct : C. slope

65. The maximum strains at the end of plastic range of structural steel is about

Correct : B. 1.5 percent

66. When the deformation arising from change of temperature is presented, the stresses set up are known as

Correct : D. Thermal stresses

67. A beam of uniform strength is the one in which

Correct : C. Bending stress is same in every section along the longitudinal axis

68. In design of a shaft, pulley and key for a system

Correct : C. Key is the weakest member

69. In case of a beam subjected to pure bending

Correct : C. The stress intensity in any fibre is proportional to the distance of the fibre from the neutral axis

70. A mild steel bolt of net cross-sectional area 8.4 sq. cm, diameter 37 will be safe to take a tensile load of about

Correct : C. 30 tonnes

71. The stress at neutral axis is

Correct : A. Zero

72. The ratio of bending moment at the centre of a simply supported beam of effective length L subjected to a central load W with that when the load W is uniformly distributed, will be

Correct : C. 2

73. A cantilever beam of square section is subjected to a load W at the free end. If the length of the beam is doubled and load reduced to half, the deflection at the free end as compared to original deflection would be

Correct : A. 4 times