31. What are the bonding theories?
32. What are the materials used for pattern making?
33. At the mould exit of a continuous caster, the metal consisting of a solidified shell with a liquid metal core exits at the rate of 35 kg S-1. Given that the latent heat of fusion is 3 × 105 J kg-1 and the total rate of heat removal by the mould is 4.2 × 106 W, the mass fraction of solid at the mould exit is . . . . . . . .
Assume that both while solid and liquid remain at the melting point, they are in the mould.
Assume that both while solid and liquid remain at the melting point, they are in the mould.
34. . . . . . . . . is the tendency of the matter to change its shape, area and volume in response to a change in temperature
35. What are the tests done for molding sand?
36. Riser are not required for casting
37. What are the parameters that amount of taper depends?
38. In a sound casting the last liquid to solidify is in the
39. Match the defects in Group 1 with possible causes in Group 2.
Group 1
Group 2
P. Misruns
1. Sand expansion
Q. Shifts
2. Molding materials
R. Blowholes
3. Improper heating of metals
S. Scabs
4. Molding and core making
| Group 1 | Group 2 |
| P. Misruns | 1. Sand expansion |
| Q. Shifts | 2. Molding materials |
| R. Blowholes | 3. Improper heating of metals |
| S. Scabs | 4. Molding and core making |