| 1. |
Permeability of moulding sand is increased due to/by |
| A. | Hard ramming |
| B. | Soft ramming |
| D. | Clay |
| Answer» B. Soft ramming | |
| 2. |
In small castings which of the following allowance can be ignored? |
| A. | Machining allowance |
| B. | Rapping allowance |
| C. | Draft allowance |
| E. | Shrinkage allowance |
| Answer» B. Rapping allowance | |
| 3. |
The design of gate should be such as to |
| A. | avoid erosion of cores and mould cavity |
| B. | prevent scum, slag and eroded sand particles from entering the mould cavity |
| C. | minimize turbulence and dross formation |
| D. | all of the above |
| Answer» D. all of the above | |
| 4. |
Mixing coal dust with moulding sand results in |
| A. | blackening of the mould |
| B. | strong mould |
| C. | good air venting |
| D. | none of the above |
| Answer» A. blackening of the mould | |
| 5. |
The order of dimensional accuracy in die casting is nearly |
| B. | 4 percent |
| C. | 0.4 percent |
| D. | 0.04 percent |
| E. | 0.004 percent |
| Answer» C. 0.4 percent | |
| 6. |
Hairlines in die casted materials result from |
| A. | chemical attack |
| B. | mechanical erosion |
| C. | thermal fatigue |
| D. | all of the above |
| Answer» C. thermal fatigue | |
| 7. |
Flux used in cupola while melting cast iron is |
| A. | lime stone |
| B. | coke slurry |
| C. | molasses |
| D. | any of the above |
| Answer» A. lime stone | |
| 8. |
Which heat treatment is applicable to aluminium alloy castings? |
| A. | Stabilizing |
| B. | Solution heat treatment |
| C. | Artificial ageing |
| D. | all of the above |
| Answer» D. all of the above | |
| 9. |
Die casting is generally not used for |
| A. | cast iron |
| B. | zinc base alloys |
| C. | aluminium base alloys |
| E. | non-ferrous metals |
| Answer» A. cast iron | |
| 10. |
The principal ingredients of moulding sands are |
| B. | silica sand, carbon, hydrocarbons and moisture |
| C. | silica sand, clay and water |
| D. | silica sand, dust and crabon |
| E. | silica sand, carbon and water |
| Answer» C. silica sand, clay and water | |
| 11. |
The function of ejection pin in die casting is to |
| A. | pushout casting off the die |
| B. | provide movable core spaces |
| C. | facilitate die casting of several components |
| D. | none of the above |
| Answer» A. pushout casting off the die | |
| 12. |
Which of the following process is used for melting of steel? |
| A. | L D process |
| B. | Kaldo process |
| C. | Duplex process |
| D. | All of the above |
| Answer» D. All of the above | |
| 13. |
Slag and dross can be removed by |
| A. | skimming from the molten metal |
| B. | using bottom pouring ladle |
| C. | using pouring basin in place of a pouring cup |
| D. | any of the above |
| Answer» D. any of the above | |
| 14. |
Sand acquires a predetermined shape under pressure and retains the same when pressure is removed. This is due to the property of sand known as |
| A. | Cohesiveness |
| B. | Plasticity |
| C. | Refractoriness |
| D. | none of the above |
| Answer» B. Plasticity | |
| 15. |
Refractoriness in the moulding sand is due to the presence of |
| A. | Clay |
| B. | Additives and Binders |
| C. | Silica |
| Answer» C. Silica | |
| 16. |
Heat treatment of castings is usually done for |
| A. | refinement of grain structure |
| B. | improving machinability |
| C. | relieving internal stress |
| D. | any of the above |
| Answer» D. any of the above | |
| 17. |
Average amount of sand required in a foundry for making one tonne of casting is nearly |
| B. | 2 tonnes |
| C. | 20 tonnes |
| D. | 0.1 tonne |
| E. | 0.2 tonne |
| Answer» B. 2 tonnes | |
| 18. |
On drying, wood |
| A. | expands |
| C. | shrinks |
| D. | changes colour |
| Answer» C. shrinks | |
| 19. |
Aluminium is not a very good material for die casting because |
| A. | it is very light but strong |
| B. | its melting point is high, it erodes the die surface and tends to react chemically with die |
| C. | it cools much slowly |
| D. | none of the above |
| Answer» B. its melting point is high, it erodes the die surface and tends to react chemically with die | |
| 20. |
Warped castings may be produced due to |
| A. | poor collapsibility of cores |
| B. | non-provision of camber allowance on the pattern |
| C. | weak flasks |
| D. | any of the above |
| Answer» D. any of the above | |
| 21. |
The most efficient shape of a series is that which |
| A. | given a minimum heat loss |
| B. | keeps the metal in molten state for longer period |
| C. | both (A) and (B) above |
| Answer» C. both (A) and (B) above | |
| 22. |
The purpose of clay in a moulding sand is to |
| A. | Act as a binder in the mould |
| B. | Make the mould refractory |
| E. | Mak the mould permeable |
| Answer» A. Act as a binder in the mould | |
| 23. |
A defect in castings in which a discontinuity is formed due to the imperfect fusion of two streams of metal in the mould cavity is known as |
| A. | scabs |
| B. | hot tears |
| C. | cold shut |
| E. | drops |
| Answer» C. cold shut | |
| 24. |
Of the following metals, the pouring rate should be minimum for |
| A. | brass |
| B. | cast iron |
| C. | aluminium |
| D. | steel |
| Answer» C. aluminium | |
| 25. |
Which of the following metal can be cast in plaster moulds? |
| A. | Yellow brass |
| B. | Manganese |
| C. | Aluminium bronzes |
| D. | All of the above |
| Answer» D. All of the above | |