1. Which of the following does not serve the purpose of using patterns in sand casting?
a) Contain core prints if the casting requires a core and need to be made hollow
b) To give the exact shape and size (in addition to the allowances) to the casting as that of the final object
c) Reduces the cost of production while used in mass production
d) Sometimes used to carry the mechanism to melt the metal/material which is to be poured into the cavity
Explanation: The pattern never carries or includes the mechanism to melt the metal, which needs to be poured into the cavity. This job needs to be done externally.
2. The function of a gated pattern is ___________
a) To produce small castings in mass production
b) To create castings of a very heavy mass
c) To create castings containing complex design
d) To create symmetrical castings
Explanation: Gated pattern manufactures huge no. of products using single time casting using a common gating inlet system. Hence, the casting needs to be small and simple and is only justified for mass production, as the pattern is used for 1-2 times only.
3. Which of the following factors affect the choice of a pattern at most times?
a) Size and complexity of the casting
b) Characteristics of castings
c) Type of molding and castings method to be used
d) Type of cooling rates to be provided
Explanation: The type of cooling rates depends upon the required strength in the casting, which cannot be controlled by the type of any pattern. Proper chills are to be used for that purpose.
4. What is a function of a riser in a sand casting?
a) Provide good mobility to the molten metal
b) Prevent cavities due to shrinkage
c) To develop holes or hollow cavities in the casting
d) To provide differential cooling rates in specific areas of the casting
Explanation: The risers also known as feeders are used to decrease the phenomena of shrinkage during solidification of the molten metal.
5. Runners, gates and risers are attached to the pattern to __________
a) Provide ease of cooling
b) Provide feed to the molten material
c) Provide design to the casting
d) Enhance the finishing of the casting
Explanation: These external elements are added to the pattern or mould cavity to enhance the flow of molten metal, hence, to enhance the casting process.
6. Pattern cannot be constructed out of which of the following materials?
a) Wood
b) Wax
c) Oil
d) Metal
Explanation: Oil is used as fuels for melting metals in various furnaces. It cannot be used for constructing a pattern, while all other materials are used for making patterns.
7. Which of the following is not a criteria for selecting pattern materials?
a) Method of moulding
b) Establishment of parting line
c) Chances of repeat orders
d) Complexity of the casting
Explanation: While selecting a pattern, pattern establishing a part line is counted under functions of the pattern, and not under the criteria for selecting it. Whereas all the other remaining are factors used for choosing the right pattern materials.
8. Which among the following wood is most widely used for making patterns?
a) White Pine
b) Mahogany
c) Teak
d) Maple
Explanation: White Pine is used most widely for making patterns because, white pine wood is soft and it is also observed that, it is comparatively easy to work on this wood. Also, this wood is comparatively cheap.
9. Which of the following is considered to be light wood?
a) Mahogany
b) Maple
c) Birch
d) White Pine
Explanation: Among these four woods, White Pine is considered to be the lightest wood. White Pine is used most widely for making patterns because, white pine wood is soft and it is also observed that, it is comparatively easy to work on this wood.
10. Steel is an alloy of which two elements?
a) Iron and Brass
b) Brass and aluminium
c) Iron and carbon
d) Carbon and aluminium
Explanation: Steel is an alloy of carbon and iron. Carbon is present in the alloy up to 2% by weight and it takes up interstitial sites of the microstructure of iron. There are three types of alloys classified in this, high alloy steel, low alloy steel and medium alloy steel.