1. Which of the following statement is true?
a) Casting is the replica of the object to be cast
b) Pattern is the replica of the casting object
c) Casting and the pattern are same things
d) Molten material is casted into the casting cavity
Explanation: Pattern is the replica of the object. Except for the core prints and allowances, the pattern exactly resembles the casting.
2. Which of the following carries the mould cavity where the metal is to be poured?
a) Casting
b) Pattern
c) Sand
d) Core
Explanation: For casting to be made, the pattern is filled with the molten material and then it is allowed to be solidified, using proper cooling rates before it is extracted out.
3. Which of the following is ‘not’ an allowance given to the pattern for casting?
a) Shrinkage
b) Draft
c) Hole
d) Machining
Explanation: A hole is made during the machining or finishing of the casting and is not a type of allowance given to the pattern.
4. What will be the machining allowance for a bore of a 405mm cast iron object to be casted?
a) 1.0mm
b) 2.0mm
c) 3.0mm
d) 5.0mm
Explanation: The machining allowance for cast iron of various dimensions is shown in the table below.
| DIMENSIONS(mm) | ALLOWANCE(mm) | ||
|---|---|---|---|
| BORE | SURFACE | COPE SIDE | |
| upto 300 | 3.0 | 3.0 | 5.5 |
| 301-500 | 5.0 | 4.0 | 6.0 |
| 501-900 | 6.0 | 5.0 | 6.0 |
5. The quality of the final product is not dependent on _______________
a) Method of withdrawal of pattern
b) Allowance provided to the pattern
c) The complexity of the casting
d) The metal used in Casting
Explanation: Metal used in casting is a concern till its viscosity affect the flow or occupation to the cavity. This does not affect the final product physically, once the metal has solidified.
6. The life of a pattern is most likely to depend upon which of the following term?
a) Number of castings produced
b) Type of cooling rate of the casting
c) Size of the casting
d) Size of the pattern
Explanation: Obviously, the more casting produced means more exposure of the pattern to the elevated temperature of molten metals and hence, slowly causing distortion to the sand grains as well as the pattern material.
7. What is the function of cores in the casting process?
a) To support the pattern
b) To provide differential cooling rates at specific portions
c) To make holes and cavities
d) For ease of flow of the molten material
Explanation: Cores are the elements used to provide hollow cavities and holes in the pattern which are difficult or non profitable to be given after the casting is done by machining.
8. Which of the following is ‘not’ an advantage of the usage of pattern in a casting of metals?
a) Using patterns to cast objects, less time is consumed for mass production
b) It is cost efficient and profitable for mass production
c) Production of the pattern requires extra effort to cast the object
d) Cores in the pattern could be used to decrease the amount of machining done for making cavities
Explanation: Production of patterns requires additional efforts but is justified for mass production only, where more products are formed in less time and overcomes the effort and cost of making patterns.
9. A draft allowance is provided to ___________
a) All linear faces
b) Only the interior dimensions
c) Only the exterior dimensions
d) Only the dimensions that are perpendicular to the parting plane
Explanation: The draft allowance is used for those dimensions which are perpendicular to the parting plane, to give out a tapered face which is machined later.
10. Which of the following is not a part of the pattern at most times?
a) Mould cavity
b) Cope
c) Molten metal
d) Core
Explanation: Molten material is poured into the mould cavity to make a casting, after solidification and hence, it does not constitute the pattern.