Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) on “Pattern Materials”.
1. Pattern cannot be constructed out of which of the following materials?
a) Wood
b) Wax
c) Oil
d) Metal
Answer: c
Clarification: 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.
2. 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
Answer: b
Clarification: 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.
3. Which among the following wood is most widely used for making patterns?
a) White Pine
b) Mahogany
c) Teak
d) Maple
Answer: a
Clarification: 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.
4. Which of the following is considered to be light wood?
a) Mahogany
b) Maple
c) Birch
d) White Pine
Answer: d
Clarification: 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.
5. Steel is an alloy of which two elements?
a) Iron and Brass
b) Brass and aluminium
c) Iron and carbon
d) Carbon and aluminium
Answer: c
Clarification: 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.
6. Which of the following is not a limitation of wooden patterns?
a) Get abraded easily
b) Absorb moisture
c) Difficult machining
d) Poor wear resistance
Answer: c
Clarification: Wooden patterns are the easiest to get machined than all the other materials which are used for making patterns, and hence is counted as one of its advantage and not limitation.
7. Metal patterns have a longer life than wooden pattern.
a) True
b) False
Answer: a
Clarification: It is true that, metal patterns have a longer life than wooden patterns, as metal patterns are stronger and accurate as compared to wooden patterns.
8. Which of the following is not a limitation of metal patterns?
a) Get rusted
b) Obtain rough surface finish
c) Expensive
d) Heavy
Answer: b
Clarification: In metal patterns, it is extremely easy to obtain a smooth surface finish. To achieve a smooth surface finish, it is counted as an advantage in metal patterns over wooden patterns.
9. Which of the following patterns do not withstand rough handling?
a) Aluminium
b) Cast iron
c) Brass
d) Steel
Answer: a
Clarification: It is one of the limitation of aluminium pattern that, it cannot withstand rough handling, while all other metal and alloy patterns can withstand it. Aluminium is the lightest metal known.
10. Which of the following has the lowest melting point?
a) Cast Iron
b) Steel
c) White Metal
d) Brass
Answer: c
Clarification: Among the given metals and metal alloys, white metal (tin base alloy) has the lowest melting point which is approximately 260 degrees Celsius.
11. Which of the following is the heaviest?
a) White
b) Brass
c) Cast Iron
d) Aluminium
Answer: b
Clarification: Aluminium and White metal are considered to be one of the lightest metals and alloys, whereas brass and cast irons are considered to be heavy materials. But, even among the two, brass is heavier than cast iron.
12. In Solid casting method, the resin mixture is kept for how much time for hardening and curing?
a) 1-2 hours
b) 2-3 hours
c) 3-4 hours
d) 4-5 hours
Answer: b
Clarification: A mould of Plaster of Paris is made, into which the resin mixture is poured, in solid casting. This mixture takes up 2-3 hours to harden and get cured.
13. Core boxes are made out of which pattern?
a) Plaster pattern
b) Wax pattern
c) Metal patterns
d) Polystyrene patterns
Answer: a
Clarification: A pattern is basically a duplicate of the object that has to be casted. It is one of the applications of plaster pattern to make core boxes and other small and intricate patterns.
14. What should the sulphur level in foam plastic be?
a) More than 1%
b) Between 0.5% to 1%
c) Less than 0.1%
d) Between 0.1% to 0.5%
Answer: c
Clarification: In foam plastic, for making pattern, the sulphur level must be below 0.1%. If the levels are higher than mentioned, it can be deleterious in manufacturing.
15. Which of the following patterns has high compressive strength?
a) Plastic pattern
b) Wax pattern
c) Polystyrene pattern
d) Plaster pattern
Answer: d
Clarification: Among plastic patterns, wax patterns and polystyrene pattern, it is plaster pattern which has the highest compressive strength. The calculated compressive strength is as high as up to 285kg/cm2.