University of Hyderabad (UoH) 2010 M.Tech Nanotechnology ENTRANCE S, ./Ph.D.(Nano Science and Technology) - Question Paper
ENTRANCE EXAMINATIONS, JUNE 2010
M.Tech./Ph.l).(Nano Science and Technology)
Marks: 75
Time: 2.00 hrs Hall Ticket no:
I. Write your Hall Ticket Number on the OMR Answer Sheet given to you. Also write the Hall Ticket Number in the space provided above.
II. Read the following instructions carefully before answering the questions.
III. This Question paper has TWO parts: PART A and PART B
1. Part A: It consists of 25 objective type questions of one mark each.
There is a negative marking of 0.33 marks for every wrong answer.
The marks obtained by a candidate in this part will be used for resolving tie cases.
2. Part B: It consists of 50 objective questions of one mark each.
There is no negative marking in this part.
3. All questions are to be answered. Answers for these questions are to be entered on the OMR sheet, filling the appropriate circle against each question. For example, if the answer to a question is (d), it should be marked as below:
No additional sheets will be provided. Rough work can be done in the question paper itself and rough work sheets provided at the end of the booklet.
4. Hand over both the question paper booklet and the OMR answer sheet at the end of the examination.
5. Calculators are permitted. Log tables are not allowed. Mobile phones are not permitted inside the Examination Hall.
6. This book contains 18 pages including this cover sheet.
o
A. 0
B. 0.5
C. 1
D. 3.5
2. C6ohas
A. 12 pentagons and 18 hexagons
B. 12 pentagons and 20 hexagons
C. 10 pentagons and 20 hexagons
D. 14 pentagons and 18 hexagons
r dx
3 /
is
a+bx
A. iln(a + &A*) +c
B. lft(a + bx) + c
C. b ln( + >x) + c
D. -ln(e+ bx) + c
a
4. Energy gap of silicon at room temperature is
A. 0.7 eV .
B. 1.1 eV
C. 5.0 eV
D. 1.5 eV
5. Meisner effect is associated with
A. superplasticity,
B. superelasicity,
..... C. superconductivity
D. superalloys
%
6. Buckey balls are made of
A. C6o molecules
B. a metallic glass
C. a polymeric material
D. superconductors
7. Skin allergy results from the interaction of sweat and other body fluids with
A. nickel ions
B. nitrogen ions
C. titanium ions
D. none of these
8. Tetragonal phase ZrC>2 can be stabilized down to room temperature by adding a small amount of
A. Y203
B. Be .
C. La
D. Sn
9. Polygonization is the phenomenon where
A. dislocations disappear into grain boundaries,
B. dislocations are generated by the operation of Frank-Read sources
C. mobile dislocations present in the material are rearranged in cell walls
D. dislocations form tangles
10. Directional Solidification can be used to produce
A. creep-resistant materials required for aerospace applications
B. shape memory alloys
C. fuel clad tubes for nuclear reactors
D. materials for Railway axles
11. The lowest density in a powder metallurgy product is its
A. green density
B. theoretical density
C. sintered density
D. smear density
12. Grain boundary sliding is promoted by
A. elevated temperatures and decreasing strain rate
B. elevated temperatures and increasing strain rate
C. sub zero temperatures and decreasing strain rate '
D. smbient temperature and increasing strain rate
13. Ultimate tensile strength is given by:
A. maximum load/original area of cross section
B. maximum load/instantaneous area of cross section
C. yield load/original area of cross section
D. yield load/instantaneous area of cross section
14. Elements A and B will form a solid solution under the following condition (aA, aB are lattice parameters of A and B respectively)
. A. laA-asI >15%
B. |aA-afi| < 15 %
C. |aA+aB| < 15 %
D. |aA+aB| > 15 %
15. Dislocations in metals are characterized by
A. etch-pitting
B. transmission Electron Microscopy
C. both A and B
D. none of these .
16. Hall-Petch slope k in the equation, ay=Oi+kd'1/2 will have the units of
A. no units because it is a constant
B. N/m2
C. N/m1/2 .
D. N/m372
17. The following are equilibrium defects
A. dislocations
B. vacancies
C. stacking faults .
D. cracks
18. Dislocation multiplication in polycrystalline materials occurs by the operation of
A. Cottrell-Bilby source
B. Johnston-Gilman source
C. Frank-Read source
D. Nabarro-Herring source
19. Eutectoid reaction is given by:
A. Liquid 1 <->Solid+Liquid2
B. Liquid l->Liquid2+Liquid3
C. Liquidl<->Solidl+Solid2
D. Solidl<->-Solid2+Solid3
20. Ellingham diagram is a representative plot between:
A. AGvsT
B. AGvsP ' C. AUvsT
D. AU vs P
21. One of the following is correct at room temperature (D is Diffusion Coefficient):
A. D (grain boundaries) < D (lattice)
B . D (grain boundaries) > D (lattice)
C. D (grain boundaries) = D (lattice)
D. D (grain boundaries) / D (lattice) =
22. A thermocouple is used to measure temperature. It works on the principle expounded by ........
A. Seebeck
B. Einstein
C. Raman
D. Roentgen
23. The number of free electrons in a completely filled energy band is
A. zero
B. one
C. infinite
D. equal to the number of valance electrons
24. Fermi level of a metal defines
A. the highest occupied level of electron energies at absolute zero
IMO
B. the lowest occupied level of electron energies at absolute zero
C. the highest occupied level of electron energies at room temperature
D. the band gap in an intrinsic semi-conductor
25. A color center is
A. an atom in a crystal that emits radiation in the visible region
B. a lattice vacancy in a crystal
G. a lattice defect in a crystal that absorbs visible light
D. a type of Frenkel defect
' 26. To achieve excellent surface finish one resorts to
A. sand casting
IMO
B. sand blasting
C. investment casting
D. slip casting
27. An intermetallic that is superconducting is
A. Ni3Al
B. NbsSn
C. Ti3Al
D. MoSi2
28. Fuel cells are based on a principle which is the converse of
A. oxidation,
B. electrolysis
C. photosynthesis
D. None of these
29. Peak strengthening in age hardening Al-Cu alloys is derived from
A. local clustering of copper atoms
B. ordering of copper atoms on {100} planes of matrix
C. formation of coherent precipitate platelets of C11AI2
D. the occurrence of an equilibrium phase C11AI2
30. Near net-shape components are manufactured by
A. hot isostatic pressing
B. hot pressing
C. activated sintering
D. hydrostatic extrusion
31. The specific heat capacity (Cv) of an insulator at a constant volume V and temperature T is given as
A. Cv = AT3
B. Cy = AT2
C. Cv = AT3+BT
D. CV = AT2+BT
32. n-type semi-conductor is obtained by doping Si with
A. B
B. A1
C. Ga
D. Sb
33. The following alloys are used for soldering -
A. Cu-Al
B. Al-Si
C. Cu-Zn
D. Sn-Ag
34. The following is correct in case of nanocrystalline materials with respect to those of conventional grain size
A. the density is high
B. the melting point is high .
C. the weight is more
D. the grain boundary specific area is more
35. Diffusion flux has the units of
A. no. of atoms/(area. time)
B. no. of atoms/(volume. time)
C. no. of atoms/(length . time)
D. no. of atoms/(mass . time)
36. The yield point phenomenon observed in annealed plain low carbon steel is due to the presence of
A. carbon
B. manganese
C. silicon
D. phosphorous
37. Wolframite is an important source of
A. titanium
B. tantalum
C. tungsten
D. thorium
38. For a closed system of fixed internal energy and volume, at equilibrium
A. Gibbs free energy is minimum .
B. Helmoltzs free energy is minimum
C. enthalaphy is maximum
D. entropy is maximum
39. The alloying element that facilitates the formation of passive layer in stainless steels
A. nickel
B. carbon
C. niobium
D. chromium
40. The deeply seated defects in thick components could be detected by
A. eddy current inspection
B. liquid penetrant inspection......
C. magnetic particle inspection
D. ultrasonic inspection
41. Krolls process produces
A. titanium
B. aluminium
C. cadmium
D. plutonium
%
42. Graphite flakes are important microstructural feature in
A. nodular cast iron
B. white cast iron
C. grey cast iron
D. hypo-eutectoid steel with 0.7% carbon
43. Major strengthening phase in Ni-base superalloys is
A. gamma-prime
B. sigma Phase
C. chromium carbide
D. eta-phase
44. The concept of entropy is introduced by:
A. zeroeth law of thermodynamics
B. first law of thermodynamics
C. second law of thermodynamics
D. third law of thermodynamics
45. Diffusion in materials occurs because of:
A. concentration gradient
B. potential gradient
C. both A and B
D. none of these
46. The following method is not used to estimate grain size in materials
A. ASTM standard chart comparison method ......... B. Newton-Raphson method
C. Heyns intercept method
D. Jeffries planimetric method
47. If the grain size of a material is decreased from 40 m to 40 mil, its oxidation resistance will
A. not change
B. increase
C. decrease
D. none of these
48. The limit of the sequence V2 ; 1/2V2 ; Jz'/zV2; 2J2V2V2
A. 1
B. 2
c. 2V2
D. 00
49. In the limit x -* oo,y = (V* + 4 - \GOis
A. 0
B. 2
C. 1/2
D. does not exist
50. Radiation pyrometers are used
A. for measurement of radiation dose '
B. for determining viscosity of the liquids
C. for temperature measurement
D. for measuring length of rail track
51. Point defects in crystal cannot be produced by
A. elastic deformation
B. plastic deformation .
C. quenching from high temperature
D. irradiation with neutrons
52. A certain buffer solution contains equal concentrations of A' and HA. The Kb for A' is 10"10. The pH of the buffer is
A. 10
B. 14
C. 7
D. 4
53. Calcium fluoride crystallizes in fluorite structure. The coordination number for the cation and anion is respectively
A. 6,4
B. 4,6
C. 8,4
D. 6,6
54. A method of removing excess solute from a colloidal solution is by
A. recrystallization
B. gas chromatography
C. distillation
D. dialysis
55. Among the following molecules, the shortest bond length is to be found in
A. C2 '
B. F2
' C. N2 \
d: o2
56. The included angle between the opposite faces of diamond pyramid indenter used in the Vickers hardness test is
|
A. |
0 |
|
B. |
90 |
|
C. |
136 |
|
D. |
180 |
57. Sensitization in stainless steels is associated with
A. depletion of Chromium to less than 12% at grain boundaries
B. depletion of Nickel to less than 8% at grain boundaries
C. depletion of Carbon to less than 0.2% at grain boundaries
D. depletion of Titanium to less than 0.5% at grain boundaries
A. hardness
B. hardenability
C. toughness
D. stiffness
59. Top-down approach is generally employed
A. for reducing the particle size of powders
B. for increasing the particle size of powders
C. for not altering the particle size of powders
D. none of the above
60. Glass ceramics by definition must contain
A. at least 50% crystalline ceramics by volume
B. 60% glassy material
C. a fully glassy structure
D. a fully ceramic material
61. Materials for orthopedic implants are based on
A. Pb
B. Mg
C. Ti
D. Be .
62. The slope of stress-strain curve in the elastic region gives
A. yield strength
B. Youngs modulus
C. toughenss
D. resilience
63. To calculate the residual stresses in a material using X-ray diffraction, the following parameter is used
A. area under the peak
B. maximum intensity of the peak
C. full width at half maximum of the peak
D. full width at full maximum of the peak
64. The term diamond-like-carbon is most commonly used to refer to
A. amorphous carbon thin films
B. graphene layers
C. crystalline diamond composites
D. all of the above
65. A powder metallurgy processing route is '
A. mechanical alloying
B. melt spinning
C. levitation
D. short peening
66. Pig iron is produced in
A. Bessemer converter
B. open hearth furnace
C. blastfurnace ,
D. Cupola
67. Electron back scattered diffraction is a technique based on
A. optical microscopy
B. scanning electron microscopy
C. atomic force microscopy
D. X-ray diffraction
68. Magnetic flux density is expressed by
A. Ampere
B. Volts
C. Weber
D. Weber/m2
69. The Reynolds number is the ratio of
A. inertial forces/Viscous forces
B. viscous forces/inertial forces
C. viscous forces/gravitational forces
D. gravitational forces/Viscous forces
70. The two elements responsible for the production of nuclear power by fusion are
A. deuterium and tritium .
B. uranium and plutonium
C. thorium and plutonium
D. tritium and uranium
71. Defects in electronic circuits can be studied by
A. magnetic particle inspection
B. thermography
C. ultrasonic testing
D. holography .
72. Differential Scanning Calorimetry is used for the determination of
A. surface topography
B. co-efficient of thermal expansion
C. phase transformations
D. grain boundary chemical analysis
73. Bronze is an alloy of copper and
A. gold
B. silver
C. tin
D. zinc
74. The following has the highest Co-efficient of Thermal Expansion
A. plastics
B. ceramics
C. tin
D. tungsten
75. The type of corrosion that produces localized attack is
A. pitting corrosion
B. uniform corrosion
C. intergranular corrosion
D. stress corrosion cracking
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| Earning: Approval pending. |
