51. The wavelength of UV spectrum ranges
52. Which of the following is disadvantage in contact mode scaning
53. Copper can be reduced from acidic copper sulphate solution by
54. For sintering of green powder compacts of copper, choose the correct statement:
P. Sintering should be done in an inert or reducing atmosphere.
Q. At a given sintering temperature, the rate of shrinkage will be higher for finer powder size.
R. Full density parts can be produced in a finite time by solid state sintering
S. Sintered compacts will have a higher strength than those made by metal working
P. Sintering should be done in an inert or reducing atmosphere.
Q. At a given sintering temperature, the rate of shrinkage will be higher for finer powder size.
R. Full density parts can be produced in a finite time by solid state sintering
S. Sintered compacts will have a higher strength than those made by metal working
55. Match the operations listed in Group I with the type of processes listed in Group II.
Group-I
Group-II
P. Blast Furnace Iron making
1. Refining
Q. BOF Steel making
2. Electrolysis
R. Hall-Heroult Process
3. Smelting
S. Bayer Process
4. Leaching
| Group-I | Group-II |
| P. Blast Furnace Iron making | 1. Refining |
| Q. BOF Steel making | 2. Electrolysis |
| R. Hall-Heroult Process | 3. Smelting |
| S. Bayer Process | 4. Leaching |
56. A rod of a metal with Young's modulus of 200 GPa is pulled in tension to a stress of 400 MPa. What is the elastic strain (in %) that is recovered, when the rod is completely unloaded?
57. Match the following:
Group 1
Group 2
P. Dulong formula
1. Ultimate analysis
Q. Carbon
2. Gray body
R. Dwight-Lloyd machine
3. Sintering
S. Radiation
4. Refractory
| Group 1 | Group 2 |
| P. Dulong formula | 1. Ultimate analysis |
| Q. Carbon | 2. Gray body |
| R. Dwight-Lloyd machine | 3. Sintering |
| S. Radiation | 4. Refractory |
58. Match the following:
Group 1
Group 2
P. Hall petch relation
1. Bulk diffusion between grain boundaries
Q. Orowan mechanism
2. Fracture of brittle materials
R. Nabarro-Herring creep
3. Grain boundary strengthening
S. Griffith criterion
4. Dispersion strengthening
| Group 1 | Group 2 |
| P. Hall petch relation | 1. Bulk diffusion between grain boundaries |
| Q. Orowan mechanism | 2. Fracture of brittle materials |
| R. Nabarro-Herring creep | 3. Grain boundary strengthening |
| S. Griffith criterion | 4. Dispersion strengthening |
59. For the following electrochemical reaction Sn + 2H+= Sn2+ + H2 if the solution has Sn2+ concentration 10-2 M and pH 5 at 298 K, which of the following is true?
Given: standard reduction potential for Sn2+ + 2e- → Sn is - 0.136 V versus SHE; pH2 = 1 atm
Given: standard reduction potential for Sn2+ + 2e- → Sn is - 0.136 V versus SHE; pH2 = 1 atm