21. A heating element that is resistant in air upto 1700°C is
22. Match the non-ferrous alloy in Group 1 with their applications in Group 2.
Group 1
Group 2
P. Ti alloy
1. Nuclear reactors
Q. Zr alloy
2. Bells
R. Ni alloy
3. Dental implants
S. Cu alloy
4. Gas turbines
| Group 1 | Group 2 |
| P. Ti alloy | 1. Nuclear reactors |
| Q. Zr alloy | 2. Bells |
| R. Ni alloy | 3. Dental implants |
| S. Cu alloy | 4. Gas turbines |
23. An alloy of Fe-0.4% C is
24. Select the incorrect statement related to the effect of a small amount of carbon addition on mechanical properties of iron.
25. As temperature increases, the electrical resistivities of pure metals $$\left( {\rho m} \right)$$ and intrinsic semiconductors $$\left( {\rho s} \right)$$ vary as follows
26. Which of the following materials do not respond well to induction hardening?
27. Match the properties in Group 1 with materials in Group 2.
Group 1
Group 2
P. Diamagnetic
1. Aluminium
Q. Paramagnetic
2. Copper
R. Ferromagnetic
3. Yittrium iron garnet
S. Ferrimagnetic
4. Cobalt
| Group 1 | Group 2 |
| P. Diamagnetic | 1. Aluminium |
| Q. Paramagnetic | 2. Copper |
| R. Ferromagnetic | 3. Yittrium iron garnet |
| S. Ferrimagnetic | 4. Cobalt |
28. Match the materials in Group 1 with their functional applications in Group 2.
Group 1
Group 2
P. Nb3Sn
1. Dielectric
Q. Ga. As
2. Soft magnet
R. Fe - 4% Si alloy
3. Super conductor
S. SiO2
4. Semi-conductor
| Group 1 | Group 2 |
| P. Nb3Sn | 1. Dielectric |
| Q. Ga. As | 2. Soft magnet |
| R. Fe - 4% Si alloy | 3. Super conductor |
| S. SiO2 | 4. Semi-conductor |
29. Match the following components to their material.
P. Bush bearings
1. Tungsten-silver
Q. Incandescent lamp filaments
2. Copper-tin
R. Cutting tools
3. Thoria doped tungsten
S. Heavy duty electrical contacts
4. Tungsten carbide-13% cobalt
| P. Bush bearings | 1. Tungsten-silver |
| Q. Incandescent lamp filaments | 2. Copper-tin |
| R. Cutting tools | 3. Thoria doped tungsten |
| S. Heavy duty electrical contacts | 4. Tungsten carbide-13% cobalt |