1. On decreasing the grain size of a polycrys talline material, the property most likely to deteriorate is
2. Most important property of steels for use in automoblie bodies is
3. p-type semi-conductor can be obtained by doping silicon with
4. Liquid nitrogen containers can be made, from
5. Match the types of corrosion in Group 1 with their examples in Group 2.
Group 1
Group 2
P. Galvanic corrosion
1. Season cracking in brass
Q. Filiform corrosion
2. Nut-bolt assembly with gasket
R. Stress corrosion cracking
3. Brass fittings joined with lead-tin solder
S. Crevice corrosion
4. Painted food can
| Group 1 | Group 2 |
| P. Galvanic corrosion | 1. Season cracking in brass |
| Q. Filiform corrosion | 2. Nut-bolt assembly with gasket |
| R. Stress corrosion cracking | 3. Brass fittings joined with lead-tin solder |
| S. Crevice corrosion | 4. Painted food can |
6. With respect to the matrix of Al-Cu alloys, G-P zones are
7. Which one of the following microstructures of a Ni-base superalloy imparts the highest creep resistance?
8. Titanium is added to molten aluminium alloys before casting for the purpose of
9. To obtain super-plasticity, the alloy should
P. have a fine grain structure that is also stable at high temperature
Q. be deformed at low temperature
R. be deformed at low strain rates
S. be deformed at high strain rates
P. have a fine grain structure that is also stable at high temperature
Q. be deformed at low temperature
R. be deformed at low strain rates
S. be deformed at high strain rates
10. Match the cast irons in Group 1 with the distinguishing microstructural features in Group 2.
Group 1
Group 2
P. Grey cast iron
1. Temper graphite
Q. Ductile cast iron
2. Pearlite
R. Malleable cast iron
3. Graphite flakes
S. White cast iron
4. Massive cementite
5. Nodular graphite
| Group 1 | Group 2 |
| P. Grey cast iron | 1. Temper graphite |
| Q. Ductile cast iron | 2. Pearlite |
| R. Malleable cast iron | 3. Graphite flakes |
| S. White cast iron | 4. Massive cementite |
| 5. Nodular graphite |