1) In metallography, microscopic method provides information about _____
a. impurities in a metal
b. location and extent of segregation
c. uniformity of structure
d. all of the above
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2) The study of metallographic includes ____
a. alloy constituents
b. failure analysis
c. metal structure
d. all of the above
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3) In microscopy, which illumination parameter is used for producing images with dark non-flat structure and bright back ground?
a. Bright field illumination
b. Dark field illumination
c. Both a. and b.
d. None of the above
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4) What is meant by recalescence in cooling curves?
a. Time required for liquefying solid components
b. Time required for completely solidifying the casted components
c. The cooling curve formed due to latent heat of fission
d. Liberated heat increases temperature of an under cooled liquid metal during nucleation
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Answer
Explanation
Related Ques
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ANSWER: Liberated heat increases temperature of an under cooled liquid metal during nucleation
Explanation:
No explanation is available for this question!
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5) The cooling curve formed when a material is solidified due to latent heat of fusion is called as ______.
a. Undercooling
b. Solidification
c. Thermal arrest
d. Thermometry
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6) Austenite phase in Iron-Carbon equilibrium diagram _______
a. is face centered cubic structure
b. has magnetic phase
c. exists below 727 oC
d. all of the above
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7) What is the crystal structure of δ-ferrite?
a. Body centered cubic structure
b. Face centered cubic structure
c. Orthorhomic crystal structure
d. None of the above
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8) Which of the following phases has a complex orthorhomic crystal structure?
a. δ-ferrite
b. α-ferrite
c. Austenite
d. Cementite
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9) In Iron-Carbon equilibrium diagram, at which temperature cementite changes from ferromagnetic to paramagnetic character?
a. 190 oC
b. 210 oC
c. 276 oC
d. None of the above
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10) Which of the following statements is/are true about Iron in Iron-Carbon equilibrium diagram ?
1. It is soft and ductile
2. It is allotropic in nature
3. It is magnetic above curie temperature
4. Below the temperature of 1539 oC, iron is in liquid state
a. 1 and 2
b. 2 and 3
c. 3 and 4
d. All of the above
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11) Which transformation starts after the nucleation of ferrite phase?
a. Bainite transformation
b. Pearlite transformation
c. Both a. and b.
d. None of the above
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12) The process of decomposing martensitic structure, by heating martensitic steel below its critical temperature is called as _______
a. Austenitizing
b. Quenching
c. Tempering
d. None of the above
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13) Which of the following processes permit the transformation of austenite to martensite, throughout the cross-section of a component without cracking or distortion?
a. Martempering
b. Marquenching
c. Both a. and b.
d. None of the above
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14) Which of the following methods measure hardenability of a metal?
a. Brinell hardness method
b. Gross Man's method
c. Rockwell hardness method
d. All of the above
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15) In which of the following methods, surface of a steel component becomes hard due to phase transformation austenite to martensite?
a. Carbonitriding
b. Flame hardening
c. Both a. and b.
d. None of the above
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16) Chemical action during corrosion converts metal into metallic component as ________
a. hydroxide
b. oxide
c. sulphate
d. all of the above
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17) What is meant by corrosion?
a. Chemical reaction between anode, cathode and electrolyte, which leads to loss of metal
b. Deterioration of metals due to reaction with its environment
c. Both a. and b.
d. None of the above
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18) Which type of chemical reaction is observed at cathode, in electrochemical corrosion?
a. Oxidation reaction
b. Peretectic reaction
c. Reduction reaction
d. None of the above
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19) Which of the following corrosions are caused due to velocity of fluid flow in pipes?
a. Bimetal corrosion
b. Cavitation corrosion
c. Galvanic corrosion
d. Intergranular corrosion
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20) Corrosion fatigue is a combined effect of _____
a. Corrosive environment and mechanical stresses
b. Cyclic loading and corrosion
c. Velocity and mechanical stresses
d. None of the above
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21) The gray cast iron has ____
a. high melting point
b. high thermal conductivity
c. low compressive strength
d. all of the above
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22) In mottled cast iron, slow cooling rate is used to obtain ______
a. white cast iron
b. gray cast iron
c. Both a. and b.
d. None of the above
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23) What is the effect of silicon on the structure of cast iron?
1. Blowholes are present in the castings
2. Increases fluidity
3. Influences the solidification of liquid alloys
4. Reacts with iron to form iron sulphide
a. 1 and 2
b. 2 and 3
c. 3 and 4
d. All of the above
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24) Nodules of graphite are observed in the microstructure of _______
a. white cast iron
b. malleable cast iron
c. spheroidal cast iron
d. all of the above
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25) Which of the following parameters is/are false for steel?
a. High carbon content
b. High melting point
c. Low damping capacity
d. None of the above
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26) Which of the following is α – β brass?
a. Admiralty brass
b. Brazing brass
c. Cartridge brass
d. All of the above
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27) In Muntz metal, if 1% of tin is added it forms _____
a. admiralty brass
b. naval brass
c. both a. and b.
d. none of the above
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28) What is the composition of cartridge brass?
a. 50 % Cu and 50 % Zn
b. 60 % Cu and 40 % Zn
c. 70 % Cu and 30 % Zn
d. 20 % Cu and 80 % Zn
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29) In precipitation hardening, at 540o C when θ phase (CuAl2) completely dissolves at grain boundaries the single phase α is obtained known as ____
a. saturated solid solution
b. homogeneous solid solution
c. heterogeneous solid solution
d. supersaturated solid solution
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30) At room temperature, hardness of precipitation hardening alloys ______
a. increases with time
b. decreases with time
c. remains constant
d. none of the above
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