1. Permeability of molding sand does not depend on which of the following factors?
a) Grain distribution
b) Degree of ramming
c) Binder contents
d) Amount of wax present
Explanation: Permeability of molding sand allows the hot gases and steams to escape out. This property does not depend on the amount of wax present.
2. Which of the following is not a function of a core?
a) It is used to form internal cavities
b) It is used to form a part of green sand mould
c) It is used as a part of gating system
d) It is used as a part of furnace
Explanation: All of the above functions are that of a core except that the core is never a part of the furnace. somehow it may be used to a path to enhance the flow of molten metal
3. Cores are subjected to severe thermal and mechanical conditions.
a) Completely true
b) Partially true
c) Completely false
d) Partially false
Explanation: Due to the direct pouring of molten metal (of elevated temperature) the cores are subjected to severe thermal and mechanical conditions and proper steps must be taken to avoid pattern or mold spoliation.
4.Which of the following is a function of a core in casting?
a) Interior cavitational passages in a casting
b) To shape an external part of a more intricate casting
c) To strengthen and improve inner and outer surface of the mold
d) All of the mentioned
Explanation: A core has versatility of its functions, all the listed functions a core can perform. Moreover, a core has more functions as well
5. A permeability of a core should be _________
a) Low
b) Moderate
c) High
d) Has no effect on casting
Explanation: The permeability of the material should be high so as to ease the flow of fluids through it during solidification, may work as gas exchanger or water absorber.
6. If a web of internal passageways and chambers is to be constructed which of the following element is most obsolete for use?
a) Cores
b) Core prints
c) Core boxes
d) Chaplets
Explanation: Core has a variety of uses. For the making of long passageways in a casting core a best suitable and cheap.
7. Which of the following statement is true?
a) Cores are permanent
b) Cores are semi-permanent
c) Cores are permanent & semi-permanent
d) Cores are not permanent
Explanation: Cores can be permanent and sometimes they can also be semi-permanent and are destroyed in order to remove the casting from mold
8.Why are core prints added to the patterns when cores are used?
a) They provide different cooling rates to the core
b) They provide support to the cores and strength to the mould and core itself
c) They are used to ease the removal of a core
d) They are used to manufacture cores
Explanation: Core prints provide support to the cores which are not stable by themselves.
9. Which of the following is not a core machine?
a) Jolt machine
b) Core blower
c) Sand slinger
d) Mill setter
Explanation: Among the following, mill setter is not any type of a core machine, while the other three are few of the types of core machine.
10. Which cores are made manually in hand filled core boxes?
a) Small sized-mass production
b) Small sized-limited production
c) Large sized-mass production
d) Large sized-limited production
Explanation: Small sized cores are made manually in the hand filled core boxes. For making large sized products for mass production, these cores cannot be employed.