MCQ
21. কোর ক্যাভিটির উপর গঠিত গ্যাস পকেটকে কী বলে?
ব্লো-হোল
হটটিয়ার
কোর ব্লো
শিফট
22. The shrinkage allowance for metal casting varies by the type of-
pattern
material
mould
metal
23. Core boxes are made out of which pattern?
Plaster pattern
Metal patterns
Polystyrene pattern
Wax pattern
24. How is the die used in injection molding cooled?
Oil
Air
Water
Contact with cold surface
25. The designing of a pattern does not include which of the following feature?
To locate the direction of the parting line and adjust the component accordingly
To determine regions and measurement of draft angles and radii of the sharp edges where allowances are to be given
To recognize and abolish the region of or where the defects could take place during casting
To 3D print the design for making the pattern.
26. What is the minimum temperature allowed to be given to the injection molding process?
120°C
130°C
140°C
150°C
27. Which of the following factors is not considered in a ram type injection molding?
Inner pressure of material
Outer pressure of material
Volume of material
Temperature of material
28. What is meant by drag in casting process?
Upper part of casting flask
Molten metal
Lower part of casting flask
Upper and lower part of casting flask
29. Which of the following pattern making machine makes wooden board?
Jointer
Mortiser
Drill press
Scroll saw
30. The axis of the cylindrical boss should be in the parting plane to have satisfactorily use of boss in casting.
True
False
31. Which of the following is not a source of moulding sand?
Sea
Lakes
Desert
Forests
32. Where does the granular molding material get loaded into?
Barrel
Hopper
Pellets
Split
33. In solid casting method, the resin mixture is kept for how much time for hardening and curing?
1-2 hours
2-3 hours
3-4 hours
4-5 hours
34. Nitriding process is used to increase surface hardness for which of the following materials?
Alloy steels
Low carbon steels
Medium carbon steels
High carbon steels
35. পারমিয়্যাবিলিটির একক কী?
m/kg
mg/m²
cc/min
কোনোটিই নয়
36. What is the minimum pressure allowed to be given to the injection molding process?
90 MPa
140 MPa
100 MPa
170 MPa
37. Which of the following material is not made by injection molding?
Nuts
Car handles
Tubes
Electrical fittings
38. নিচের কোনটি কুশন অ্যাডিটিভস-এর উপাদান?
কাঠের গুঁড়া
সিলিকা
সী-করলা
গ্রাফাইট
39. Which of the following non-metallic material is not used in the synthesis of molds?
Magnesite
Zircon
Silimanite
Valcanised rubber
40. ঢালাইলোহার ক্ষেত্রে বালির পারমিয়্যাবিলিটি কত হওয়া উচিত?
20-30.cc/min
40-50 cc/min
30-40 cc/min
50-60 cc/min