3. A crystal structure in a regular array of atoms is arranged in one of the space lattices
Correct : C. 14
4. The linear disturbance of atomic arrangement is known as
Correct : C. dislocations
5. is a system of notations of planes within a crystal of space lattice
Correct : C. miller indices
6. Atom movements in twinnning are much
than atomic spacing
Correct : B. less
7. diffusion implies atomic movement along the surface of a plane
Correct : B. surface
8. In a simple cubic structure, [100] and
(100) parallel?
Correct : A. no
9. The miller indices of a plane are proportional to :
Correct : A. the reciprocal of numerical parameters of the intercepts
10. A material having different properties in different directions is known as
Correct : B. anisotropic
11. Presence of carbon atom in iron is an example of impurity
Correct : B. interstitial
12. Directions of edge dislocation & burger vector are to each other
Correct : A. perpendicul ar
13. On thermal excitation this defect may cause
Correct : A. vacancy
14. The grain boundary area decreases when a polycrystalline material is heated
Correct : B. above recrystalliza tion temp.
15. Ideal crystals have
Correct : A. no imperfectio ns
16. The imperfections may be minimised by
Correct : D. all of the above
17. Volume imperfections can be
Correct : D. noncrystalli ne regions
18. The cross slip occurs in :
Correct : B. screw dislocation
19. .......... defects are inperfect point like region in a crystal.
Correct : B. point
20. A ............is the simplest point defect and envolves a missing atom within a metal.
Correct : B. vacancy
21. -------- imperfections involve vacancies of a pair ions of opposite charges.
Correct : B. schottky
22. The displacement distance for atoms around the dislocation is the---- --.
Correct : A. burger vector
23. -------- dislocation can glide and climb.
Correct : B. edge
24. -------- are difined as the irregularities in the structure of metals.
Correct : B. dislocation
25. Surface defects are the -------- dimensional regions in a crystal.
Correct : B. two
26. -------- dislocation plays an important role in crystal growth.
Correct : B. screw
27. Work hardening reduces:
Correct : D. ductility
28. -------- is the low temperature phenomenon which results in the rstoration of the physical properties without any observable change in microstructure.
Correct : B. recovery
29. Grain growth is an increase in ----- --.
Correct : A. grain size
30. A metal is said to be--------- worked, if it is mechanically processed below the crystallization temperature of the metal.
Correct : B. cold
31. Chances of cracks propogation is more in:
Correct : B. cold working
32. In ------working refinement of crystal occures.
Correct : B. hot
33. -------- working is always accompanied by strain hardening.
Correct : B. cold
34. -------- working increases ultimate tensile strength.
Correct : A. cold
35. Annealing is done:
Correct : C. relievin g stresse s
36. Among the crystal structure, which has the highest packing fraction.
Correct : B. fcc
37. The miller indices are the same for:
Correct : A. parall el plane s
38. The crystal structure of silver is:
Correct : A. fcc
39. 0.68 is the atomic packing factore of:
Correct : A. bcc
40. (001) is a plane of the cube and is:
Correct : A. horizontal
41. The crystal structure of all the following material is HCP except:
Correct : D. aluminium
42. The crystal structure of graphite is:
Correct : A. hcp
43. The crystal structure of Germanium is:
Correct : D. diamon d cube
44. How many atoms are there per unit cell in a body centered cubic lattice system?
Correct : A. 2
45. How many molecules per unit cell are there in a face centered cubic lattice?
Correct : B. 4
46. The crystal structure of most common metal is:
Correct : B. cubic
47. The metal which has got BCC structure is:
Correct : B. tungsten
48. The structure of SiO2 quartz is:
Correct : A. hcp
49. The metal which has HCP structure is:
Correct : C. magnesium
50. The crystal structure of the following materials is FCC except:
Correct : B. magnesium
51. A crystal structure in a regular array of atoms is arranged in one of the:
Correct : C. 14
space lattices
52. There are 2 atoms in a unit cell of:
Correct : A. body centered cubic space lattice
53. Which of the following elements has hexagonal close packed structure?
Correct : C. cadmium
54. Atomic packing factore is maximum for:
Correct : C. fcc
55. The crystal structure of brass is:
Correct : B. fcc
56. The crystal structure of gamma iron is:
Correct : C. fcc
57. Cold work is done on metals:
Correct : A. below thermal critical range
58. In crystal imperfections, the lattice sites from which atoms are missing are called:
Correct : B. vacancies
59. Which of the following metals does not have face centered cubic structure?
Correct : C. tin
60. The process which occures with heating in excess of that used recovery is called:
Correct : B. recrystalliz
at ion
61. Recrystallization temperature of aluminium is 150˚ C and that of copper is:
Correct : B. 200˚
62. The linear disturbance of atomic arrangment is known as:
Correct : C. dislocations
63. Every point of a space lattice has ------ surrounding:
Correct : D. identical
64. ------- parameter means the dimensions of the unit cell in any of the crystallographic arrangements.
Correct : D. lattice
65. ------- is defined as the number of nearest atoms which are directly surrounding a given atom.
Correct : D. co- ordinatio n number
66. The ratio of the volume of atoms per unit cell to the total volume occupied by the unit cell called------ --.
Correct : B. atomi c packin g factor
67. -------- is a system of notation of planes within a crystal of space lattice.
Correct : C. miller indices
68. The change in dimension of foems of matter under the action of applied forces is called---.
Correct : C. deformation
69. ------- deformation is the deformation which disappears when the load is removed.
Correct : B. elastic
70. In metals the plastic deformation generally takes place by the process of ----
----.
Correct : B. slipping
71. In ----- the orientation of the crstal above and below the slip plane is same after deformation as before.
Correct : B. slip
72. ------- defects are imperfect point like regions in a crystal.
Correct : B. point
73. A ------is the simplest point defect and involves a missing atom within a metal.
Correct : B. vacancy
74. ------- imperfection involves vacancies of pair of ions of opposite charges.
Correct : B. schottky
75. A linear disturbance of atomic arrangement which can move very easily on the slip plane through the crstal is known as -----.
Correct : C. dislocation
76. The Burger's vectore is at------- to the edge dislocation line.
Correct : C. right angle
77. In ------dislocation only shear stress field exists.
Correct : C. screw
78. ------ slip is process where by a screw dislocation glides into another slip plane having a slip direction in common with the original slip plane.
Correct : C. cross
79. -------- dislocation plays an important role in crystal growth.
Correct : C. screw
80. Non-random alignment of crystals or molecules is known as ----- orientation.
Correct : C. perferred
81. Chances of crack propagation is more in --
-----.
Correct : A. cold working
82. The tiny block formed by the arrangement of small group of atom is called ----- --.
Correct : A. unit cell
83. According to Bravais there are ------ possible types of space lattice in the seven basic crystal system.
Correct : B. 14
84. In metals the plastic deformation generally takes place by the process of ----
-----.
Correct : B. slipping
85. The shear stress required to produce slip on a crystal plane is called the ------ shear stress.
Correct : A. critical resolve d
86. --------- occure over wide planes.
Correct : A. slip
87. In -------- every atomic plane is involved.
Correct : C. twinning
88. A linear disturbance of atomic arrangement, which can move very easily on the slip plane through the crystal is known as ------ --.
Correct : C. dislocation
89. The Burger's vectore is at------- to the edge dislocation line.
Correct : C. right angles
90. In a screw dislocation Burger's vectore is -
------- to the linear defect but there is distoration of the plane.
Correct : A. parallel
91. In -------- dislocation only shear stress field exists.
Correct : C. screw
92. Cold working increasings:
Correct : C. ultimat e tensile
93. Alloying elements of impurities greatly increase the lattice imperfections which decrease/increase the conductivity.
Correct : A. decrease
94. Any mechanical process that increases the number of dislocations will result in decrease/increase in the electrical resistance of the metal.
Correct : B. increases
95. The capacit of material to undergo deformation under tension without rupture is known as:
Correct : D. ductility
96. The structure of common glass is:
Correct : A. amorphous
97. Which of the following materials has body centered cubic structure?
Correct : A. molybdenum
98. Which of the following materials does not have body centered cubic structure?
Correct : D. calcium
99. Which of the following factores govern the grain size?
Correct : D. all of the above
100. In -------- fracture the surface obtained in shining and accompanied with the formation of slip planes.