Engineering Materials 15

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Objective Questions and Answer: Engineering Materials 15

Subject: Engineering Materials 15

Part 15: Objective questions and answers of Engineering Materials

 

Q1. Super conduction by metals is observed in the temperature range of

a) Below 10°K

b) Above 100°K

c) Around 0°C

d) Around 100°C

 

Q2. Which of the following constituents of steels is softest and least strong?

a) Austenite

b) Pearlite

c) Ferrite

d) Cementlte

 

Q3. Which of the following represents the allotropic forms of iron

a) Alpha iron, beta iron and gamma iron

b) Alpha iron and beta iron

c) Body centred cubic a-iron and face centred cubic a-iron

d) Alpha iron, gamma from and delta iron

 

Q4. The following types of materials are usually the most ductile

a) Face-centred cubic lattice

b) Body-centred cubic lattice

c) Hexagonal close-packed lattice

d) All of the above

 

Q5. Pure iron is the structure of

a) Ferrite

b) Pearlite

c) Anstenite

d) Ferrite and cementite

 

Q6. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is

a) 770°C

b) 910°C

c) 1050°C

d) Below recrystallisation temperature

 

Q7. Gamma iron exits at following temperature

a) Room temperature

b) Near melting point

c) Between 1400°C and 1539°C

d) Between 910°C and 1400°C

 

Q8. Ferromagnetic alpha iron exists in temperature range of

a) Below 723°C

b) 770 – 910°C

c) 910-1440°C

d) 1400-1539°C

 

Q9. Paramagnetic alpha iron changes to gamma iron at

a) 770°C

b) 910°C

c) 1440°C

d) 1539°C

 

Q10. A reversible change in the atomic structure of steel with corresponding change in the properties is known as

a) Molecular change

b) Physical change

c) Allotropic change

d) Solidus change

 

Q11. The molecules in a solid move

a) In a random manner

b) In a haphazard way

c) In circular motion

d) Back and forth like tiny pendulums

 

Q12. The crystal structure of gamma iron is

a) Body centred cubic

b) Face centred cubic

c) Hexagonal close packed

d) Cubic structure

 

Q13. The crystal of alpha iron is

a) Body centred cubic

b) Face centred cubic

c) Hexagonal close packed

d) Cubic structure

 

Q14. The metallic structure of mild steel is

a) Body centred cubic

b) Face centred cubic

c) Hexagonal close packed

d) Cubic structure

 

Q15. For the allotropic forms of iron, the points of arrest are

a) The points where no further change oc-curs

b) Constant for all metals

c) The points where there is no further flow of metal

d) The points of discontinuity

 

Q16. The percentage of carbon in pig iron varies from

a) 0.1 to 1.2%

b) 1.5 to 2.5%

c) 2.5 to 4%

d) 4 to 4.5%

 

Q17. The percentage of carbon in grey iron castings usually varies between

a) 0.5 to 1%

b) 1 – 2%

c) 2.5 to 4.5%

d) 5 – 7%

 

Q18. Pig iron is the name given to

a) Raw material for blast furnace

b) Product of blast furnace made by reduction of iron ore

c) Iron containing huge quantities of carbon

d) Iron in molten form in the ladles

 

Q19. The unique property of cast iron is its high

a) Malleability

b) Ductility

c) Surface finish

d) Damping characteristics

 

Q20. Cast iron is characterized by minimum of following %age of carbon

a) 0.20%

b) 0.80%

c) 1.30%

d) 2%

 

Part 15: Objective questions and answers of Engineering Materials

 

Q1. Answer a

Q2. Answer c

Q3. Answer d

Q4. Answer a

Q5. Answer a

Q6. Answer a

Q7. Answer d

Q8. Answer a

Q9. Answer b

Q10. Answer c

Q11. Answer d

Q12. Answer b

Q13. Answer a

Q14. Answer a

Q15. Answer d

Q16. Answer d

Q17. Answer c

Q18. Answer b

Q19. Answer d

Q20. Answer d

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