This set of Manufacturing Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Fundamentals of Casting”.
1. If we decrease the freezing range then the fluidity of metal will?
c) Will not change
d) Will increase then decrease
Explanation: Fluidity is inversely proportional to freezing range. When freezing range decreases, fluidity of metal will increase.
2. According to Chvorinov’s rule the solidification time is a function of volume and surface area and is given by the relationship between volume, area and some exponential power ‘n’. Here the value of n is
Explanation: n=2 in Chvorinov’s rule. Solidification time is a function of volume and surface area as stated by Chvorinov’s rule.
3. Which one of the following expands during contraction?
a) Mild steel
b) Grey cast iron
Explanation: Grey cast iron expands upon contraction. Mild steel, Aluminium and copper do not expand during contraction process.
4. Dissolved gases may be removed from molten metal by
a) Flushing or purging with inert gas
b) Melting and pouring the metal in vacuum
c) Flushing or purging with inert gas or Melting and pouring the metal in vacuum
d) None of the Mentioned
Explanation: Dissolved gases may be removed from molten metal either by flushing or purging with inert gas or melting and pouring the metal in vacuum.
5. Doubling the time in flat mould will increase the thickness of wall skin by what percentage?
Explanation: Thickness is proportional to √ time. When time is doubled in flat mould, thickness of wall skin will increase by 41%.
6. Solidification of casting does not depend upon which factor?
a) Type of metal
b) Thermal properties of metal
c) Geometric relationship between volume and surface area
d) Surface tension.
Explanation: Surface tension is a fluid property and solidification time of casting does not depend upon any fluid property.
7. The following characteristic of molten metal influence the fluidity
1) Mushy zone
3) Surface tension
Which one of the following is correct?
b) 1 only
Explanation: All the above mention characteristics influence fluidity. Fluidity in casting is used to designate the casting material ability to fill the mould cavity.
8. What is the function of cores used in casting?
a) To remove dissolved gases
b) To avoid defects
c) To form hollow region
d) To reduce shrinkage porosity
Explanation: Cores are used to form hollow region. It is difficult to form hollow region in a material using sand casting.
9. Which one of the statement is correct in metal casting?
a) Rapid cooling produces a solidified skin or shell
b) Those grain that have favorable orientation will grow preferentially
c) Cast iron has wide mushy zones
d) Lack of uniformity in grains size and distribution will cause anisotropic properties
Explanation: Cast iron has low range of mushy zone. Rapid cooling produces a solidified skin or shell and Lack of uniformity in grains size and distribution will cause anisotropic properties.
10. Assertion (A): Chills are used to reduce shrinkage porosity.
Reason (R): the function of chill is to increase the rate of solidification in a critical region.
a) Both A and R is correct and R is a correct explanation for A
b) Both A and R is correct and R is an incorrect explanation for A
c) A is wrong but R is correct
d) A is correct but R is wrong
Explanation: Chills are used to reduce shrinkage porosity and the function of chill is to increase the rate of solidification in critical region.
Sanfoundry Global Education & Learning Series – Manufacturing Engineering.
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