I. Multiple Choice Questions, 1 point per question.
1. A low pouring temperature can lead to slag holes.
A. Correct; B. Incorrect.
2. Sand cores are primarily positioned and supported in the mold by core prints.
A. Correct; B. Incorrect.
3. The sand core is a component that forms the internal cavity of the casting. How is it made?
A. In a core box; B. Using patterns; C. Shaped manually by workers.
4. Split-pattern molding is suitable for complex-shaped castings such as cylinders, sleeves, and valve bodies.
A. Correct; B. Incorrect.
5. For the two-way junction plate part as shown in Figure 105, with single-piece or small batch production, which manual molding method should be selected?
A. Solid pattern molding; B. Split-pattern molding; C. Squeeze molding.
6. Machine molding cannot use squeeze molding.
A. Correct; B. Incorrect.
7. Oxygen tanks and regulators must not come into contact with grease.
A. Correct; B. Incorrect.
8. When using acidic electrodes, which method should be adopted:
A. Direct Current (DC) with straight polarity; B. Direct Current (DC) with reverse polarity;
C. Direct Current (DC) with either straight or reverse polarity; D. Alternating Current (AC) or Direct Current (DC).
9. The internal quality of joints produced by flash butt welding is better than that of resistance butt welding.