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Material Science
1) A body which does not contain voids or empty spaces is known as
a. An isotropic bodyb. continuous bodyc. heterogeneous bodyd. crystalline body
2)If a body has identical properties all over it is known as
a.isentropicb. ductilec.homogenousd.elastic
3) Some engineering materials are made up of more than one phase, with different mechanical properties such materials are known as
a. Discontinuousb. Brittlec. Elasticd. Heterogeneous
4) Which of the following is the hardest material?
A. high speed steelb. Diamondc. stainless steeld. cemented carbide
5. The miller indices of the diagonal plane of cube area.110b.111c. 100d. 000 6. Burgers vector isa. estimation of force in subsitutional atomsb. a defect in crystal structurec. defect in crystal latticesd. property of dislocation
7. Close packed hexagonal space lattice is found ina. chromium , tungstenb. cobalt, antimony and bismuthc. aluminum , copperd. calcium , magnesium
8. The atomic packaging factor for Face centered cube is nearly a) 0.74 b) 0.52 c) 0.68 d) 0.81
9. Which of the following element has H.C.P structure?a. aluminumb. molybdenumc. cadmiumd. chromium
10. The material which has the same elastic properties in all direction is called
e. brittle materialf. ductile materialg. homogenous materialh. isotropic material
11. Recrystallisation temperature is .......................times the melting point for pure metals and............................ times the melting temperature for alloys
a) .3,.5b) .2,.1c) .6,.9d) 1,2
12. ..................................... is indicative of the rate at which atoms diffuse
e) temperaturef) speciesg) massh) diffusion coefficient D
13. ----------------- are responsible for the functioning of most semi conductor devices
a) line defectsb) impuritiesc) grain boundriesd) tilt boundries
14. ------------------- defects in a crystal lattices causes an increase in its internal energy
e) Point defectsf) Line defectsg) Structure defects h) Volume defects
15. Whenever the arrangement of atoms is not in proper sequence throughout the crystal the defect caused is known as
a) grain boundryb) tilt boundryc) stacking faultd) edge dislocation
16. whenever grains of different orientation separates the general pattern of atoms and exhibits as boundry, the defect caused is called
e) tilt boundryf) grain boundryg) twin boundryh) stacking fault
17. whenever a half plane of atoms is inserted between the planes of atoms in perfect crystals the defect produced is known as
a) edge dislocationb) screw dislocationc) interstitial defectd) electronic defect
18. --------------------- defect is the combination of vacancy and interstials
e) schottky defectf) grain boundaryg) twin boundaryh) frankel defects
19. During recovery of a cold worked poly crystalline material dislocations
a) migrateb) multiplec) rearranged) mostly disappear
20. Recrystallisation temperature is onee) at which new spherical crystals first begin to form ones
when a strained metal is heatedf) at which crystal begins to appearg) at which crystal start growing in sizeh) at which polycrystalline changes occur
21. a ductile fracture is characterized bya) rapid rate of crack propagationb) negligible deformationc) fragmentation into more than two piecesd) appreciable plastic deformation prior to propagation of
crack
22. the fatigue strength of materials increases
e) with temperaturef) by under stressing the specimeng) by having scratch on the surfaceh) by having notch on the surface
23. The property of material by which slow extension of materials takes place with the time at constant load is known as
a) creepb) plasticityc) elasticityd) Malleability
24. Fatique cracks in metals normally starts ate) centre of the specimenf) any spot in the specimeng) core of the specimenh) ends of the specimen
25. Which of the following material can withstand maximum shock without failure?
a) white cast ironb) chilled cast ironc) malleable cast irond) grey cast iron
26. The order in which events lead to fatigue failure is
e) crack growth , fracture , nucleationf) fracture, crack growth, nucleationg) crack growth, nucleation, fractureh) nucleation, crack growth, fracture
27. Which of the following material can bear sudden and excessive shocks better?
a) wrought ironb) cast ironc) pig irond) white iron
28. dislocation cross- slip is difficult in those material which have
e) high stacking fault energyf) large number of slip systemsg) low stacking fault energyh) high work - hardening rate
29. In compression, a prism of brittle material will break
a) by crushing into piecesb) by forming a buldgec) in direction perpendicular to application of loadd) by shearing along oblique plane
30. Below ECT small grain sized materials stronger due to .......................... to improve strength
e) grain sizef) high density of grain boundariesg) space between grainsh) grain boundary
31. when a piece of 0.2% carbon steel is heated above third critical point the steel is a solid solution of carbon in gamma iron and it is called
a) Austeniteb) Peralitec) Cementited) Eutectoid
32. A steel with 0.8% carbon and 100% peralite is called
e) Austenitef) Solidusg) Eutectoidh) Peralite
33. eutectoid steels have carbon contenta) 0.83%b) 0.2%c) 0.7%d) 1.7%
34. Cast iron containing 6.6% carbon is
e) Black in colour containing peralitef) Black in colour containing ferriteg) Grey in colour containing peralite and ferriteh) Whitish containing cementite only
35. iron - carbon alloys containing 1.7 to 4.3% carbon is called as
a) eutectic cast ironb) hyper - eutectic cast ironc) hypo - eutectic cast irond) white cast iron
36. Pure iron has the structure of
e) Peralitef) Austeniteg) Cementiteh) Ferrite
37. if the steel at room temperature is magnetic, the presence of which constituent can be ruled out
a) Ferrite b) Peralitec) Austenited) Cementite
38. what is the minimum carbon % required in steel, so that it may respond to hardening by heat treatment
e) 0.2%f) 1%g) 1.2%h) 2%
39. austenite is the combination ofa) ferrite and cementiteb) perlite and ferritec) ferrite and iron graphited) cementite and perlite
40. Hypo eutectoid steels have carbon content
e) greater than 0.83%f) equal to 0.83%g) more than 2%h) less than 0.83%
41. Heat treatment in which a material that is exposed to an elevated temperature for an extended time period and then slowly cooled is called as __________
a) Nitridingb) Annealingc) Carburisingd) Carbonitriding
42. _________ refers to accelerated cooling.
e) Quenchingf) Annealingg) Temperingh) Hardening
43. ________________ is the process of heating a martensite steel at a temperature below the eutectoid transformation temperature for a specified time period and is cooled slowly to room temperature.
a) Flame hardeningb) Induction hardeningc) Carbonitridingd) Tempering
44. What is the temperature range for high temperature tempering?
e) 500ºC to 650ºCf) 250ºC to 350ºCg) 350ºC to 450ºCh) 650ºC to 750ºC
45. Heat treatment of a steel involving a slow cool through the martensite transformation range to reduce stresses associated with that crystallographic change is called as __________
a) Austemperingb) Annealingc) Martemperingd) Nitriding
46. ___________ is a process of introducing both nitrogen and carbon to obtain hard surface of the steel components.
e) Carburising f) Carbonitriding g) Nitriding h) Hardening
47. In ________ a hardened steel ball indenter is forced into the surface of the metal to be tested.
a) Izod testb) Charpy testc) Rockwell hardness testd) Brinell hardness test
48. _________ is an type of impact test.
e) Brinell hardness testf) Vickers hardness testg) Izod testh) Rockwell hardness test
49. Both hardness and tensile strength are indicators of a metal’s resistance to........................
a) elastic deformationb) plastic deformationc) viscoelastic deformationd) load
50. What is the diameter of the hardened stell indenter used in brinell hardness test?
e) 10mmf) 20mmg) 35mmh) 50mm
Answers
1) b 2) c3) d4) b5) a6) d7) b8) a9) c10)d
Answers
11) a12) d13) b14) a15) c16) b17) a18) d19) c20) a
Answers
21) d22) b23) a24) b25) c26) d27) a28) c29) d30) b
Answers
31) a32) c33) a34) d35) b36) d37) c38) a39) c40) d
Answers
41) b42) a43) d44) a45) c46) b47) d48) c49) b50) a
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