Quiznetik

Material Science | Set 6

1. Mechanical stressing of crystal structure -- ------ conductivity of metal.

Correct : A. decreases

2. -------- crystallises in the diamond cubic lattice.

Correct : C. diamond

3. --------- deformation is the deformation which disappears when the load is removed.

Correct : A. plastic

4. Atom movements in twinning are much less than ----- --.

Correct : A. atomic spacin g

5. The displacement distance for atoms around the dislocation is the---- --.

Correct : A. burger vector

6. Grain growth is an increase in ----- --.

Correct : B. grain size

7. Slow and progressive deformation of material with timer under constant stress is called----.

Correct : A. creep

8. ------ are elastic members which distort under load and regain their original shape when load is removed.

Correct : B. springs

9. An unit cell is -------

Correct : A. the smallest group of the atoms which when regularly repeated forms the crystal.

10. A material having different properties in different directions is known as:

Correct : B. anisotropic

11. Miller indices are the same for:

Correct : D. parall el plane s

12. On application of thermal energy, a dislocation vanishes:

Correct : D. both a and b

13. Volume imperfections can be:

Correct : D. noncrystalli n e regions

14. The cross-slip occures in:

Correct : B. screw dislocatio n

15. The overall electrical neutralit is maintained in:

Correct : A. frenkel\ s defect

16. Critical resolved shear stress is a phenomenon related to

Correct : C. slip

17. Strain hardening will take place if

Correct : A. obstacle are present

18. The overall electrical nutrality is maintained in

Correct : A. frenkel\ s defect

19. Volume imperfections can be

Correct : D. non crystalline region

20. The omperfections can be minimised by

Correct : D. all of the above

21. Presence of carbon atom in FCC iron at 1100 degrees is an exampl of

Correct : A. interstitial defect

22. Miller indices are same for

Correct : D. parall el plane s

23. A metal which posseses BCC is

Correct : B. sn

24. A material having different properties at different directions is known as

Correct : B. anisotropic

25. The crystal structure of most of the common metals are

Correct : A. cubic

26. In the simple cubic structure,are direction [100] and plane (100) parellel ?

Correct : A. no

27. Structure of thorium is

Correct : B. fcc

28. The capacity of a metal to exhibit cosiderable elastic recovery upon release is known as

Correct : D. resilience

29. The property of the material which enables the formation of permanent deformation without fracture is known as

Correct : B. plasticity

30. ......... working as always accompanied by strain hardening

Correct : B. cold

31. Mechanical streesing of crystal strucure .........conductivity of metals.

Correct : A. decreases

32. The grain boundry area decreases when the polycrystalline material heated ..

Correct : D. above 0.5 tm

33. The critically resolved shear stress Tcr=(P cos α cos β)/A . the equation known as .....law.

Correct : B. schmid\s

34. The shear stress required to produce slip on crystal plane is called........ shear plane.

Correct : A. critical resolve d

35. .......occures over wide planes

Correct : A. slip

36. In ........every atomic plane is envolved

Correct : C. twinning

37. In metals the plastic deformation is generally takes place by

Correct : B. slip

38. According to bravais ,there are ......... possible types of space lattice in the seven

Correct : B. 14

39. The burger vector is at ..... to the edge dislocation line

Correct : B. perpendicul a r

40. In .............disloction only shear stress field exists.

Correct : C. screw

41. .................. imperfections involves vacancies of pair of ions of opposite charges

Correct : B. schottky

42. Every point of a space lattice has ....... surrounding.

Correct : D. identical

43. It is possible to continuously work on the metal during ....... working

Correct : A. hot

44. The process of formation of new grains is called......

Correct : B. nucleation

45. The stress required to produce same deformation is higher in case of......... polycrystalline material as compared to ..... ...polycrystalline materials.

Correct : B. fine grained,co ar se grained

46. mechanical testing gives information about

Correct : C. mechanical properties of metal

47. when material is tested to evaluate properties, it is called as

Correct : A. destructive testing

48. during the product design and its manufacturing process, material undergoes                      test

Correct : D. all of the above

49. engineering materials are tested for the purpose of

Correct : D. all of the above

50. tensile test gives values of material properties under the action of                      forces

Correct : B. tensile

51. total energy absorbed by material in elastic deformation is known as

Correct : A. resilience

52. material obey's hooks law in region

Correct : B. elastic deformation

53. is constant at the yield point

Correct : B. stress

54. the material shows atrain at cnstant stress that point is known as

Correct : A. yield stress

55. the stress-strain diagram becomes non-linear

Correct : A. after yield point

56. material shows localised deformation after

Correct : B. after uts

57. area under stress-strain curve in elastic region is called as

Correct : A. resilience

58. total area under stress-strain curve is called as

Correct : A. toughness

59. toughness is defined as total energy absorbed by material in

Correct : C. both of the above

60. modulus of toughness is

Correct : B. toughness/vo lume

61. brittle material shows toughness

Correct : A. low

62. ductile material shows toughness

Correct : B. high

63. is the property of a material by which it can be drawin into wires

Correct : A. ductility

64. resistance of a material for its deformation is called as

Correct : C. stiffness

65. materials like Al shows better

Correct : D. all of the above

66. modulus of resilience is

Correct : C. energy absorbed / volume

67. modulus of resilience is given as

Correct : C. σ2/2e

68. A tensile test specimen has cross section

Correct : D. all of the above

69. for tensile testing machine is used

Correct : A. universal testing

70. engineering stress is defined as

Correct : C. applied load / (original cross section area)

71. true stress is defiend as

Correct : D. instantaneou s load / (original cross section area)

72. for measuring the elongation of specimen on UTM during tensile test is used

Correct : D. extensomete r

73. dummy pointer on load - cell is used to indicate

Correct : C. ultimate load

74. after ultimate stress, stress goes on

Correct : A. reducing

75. all the calculations in tensile test are carried out on a particular distance which is called as

Correct : A. gauge length

76. any sudden change in cross section leads to the formaiton of area

Correct : B. stres concentratio n

77. the graphical representation of results of tensile test is known as

Correct : A. stress strain curve

78. in engineering stress we consider

Correct : A. original cross section

79. during the tensile test, the length of specimen and its cross section area

Correct : C. increases, decreases

80. the test which come under the group of destructive tests is

Correct : D. none of the above

81. the tests which come under the group of destructive tests are

Correct : D. any one of above

82. the material which does not show the predefined yield stress, the yield stress can be determined by

Correct : B. proof stress method

83. the relation between true stress and engineering stress is

Correct : B. σt=σe(1+e)

84. the relation between true strain and engineering strain is

Correct : D. et=ln(1+e)

85. in tensile stress, necking occurs at a point where

Correct : D. (dσt/det) = σt

86. property is not directly shown on the stress strain curve

Correct : D. all of the above

87. is maximum value of stress upto which stress is directly proportional to strain

Correct : B. proportional limit

88. is the stress at which material shows a specified amount of plastic deformation

Correct : C. proof stress

89. to calclulate proof stress, method is used

Correct : A. offset

90. for calculating a proof stress, a parallel line is drawn at

Correct : B. 0.2% of total elongation

91. is the maximum value of stress in the plastic region

Correct : A. uts

92. for ducttile material is the maximum value of stress the material can sustain

Correct : A. uts

93. Breaking Stress is also called as

Correct : C. fracture stress

94. is the minimum value of stress in plastic region

Correct : D. breaking stress

95. unit of toughness is

Correct : B. joule

96. for brittle material its

Correct : C. yield stress and uts and breaking are very close

97. in tensile test, during strain hardening material after cold working shows                      in strength with decreased toughness

Correct : B. increase

98. during tensile test, if gauge length                   percentage elongation increases due to localised elongation

Correct : A. decreases

99. states that geometrically similar samples having constant L/D ratio shows same % elongation

Correct : B. barba\s law

100. during tensile test, type of loading should be avoided

Correct : D. all of the above