Engineering Materials objective questions with answers part2

Q1. Isotropic materials are those which have the same
(A) elastic properties in all directions
(B) stresses induced in all directions
(C) thermal properties in all directions
(D) electric and magnetic properties in all directions

Q2. Recrystallization temperature is one
(A) at which crystals first start forming from molten metal when it is cooled
(B) at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated
(C) at which change of allotropic form takes place
(D) at which crystals are destroyed on heating

Q3. Points of arrest for iron correspond to
(A) stages at which allotropic forms change
(B) stages at which further heating does not increase temperature for some time
(C) stages at which properties do not change with increase in temperature
(D) there is nothing like points of arrest

Q4. Delta iron occurs at temperature of
(A) room temperature
(B) above melting point
(C) between 1400°C and 1539°C
(D) between 900°C and 1300°C

Q5. A material is known as allotropic or polymorphic if it
(A) has a fixed structure under all conditions
(B) exists in several crystal forms at different temperatures
(C) responds to heat treatment
(D) has its atoms distributed in a random pattern

Q6. Super conduction by metals is observed in the temperature range of
(A) below 10°K
(B) above 100°K
(C) around 100°C
(D) around 1000°C

Q7. Which of the following constituents of steels is softest and least strong
(A) austenite
(B) pearlite
(C) ferrite
(D) cementlte

Q8. 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

Q9. 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

Q10. Pure iron is the structure of
(A) ferrite
(B) pearlite
(C) ferrite and cementite
(D) ferrite and pearlite.

Q11. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
(A) 770°C
(B) 920°C
(C) 1150°C
(D) above recrystallization temperature.

Q12. Gamma iron exits at following temperature
(A) room temperature
(B) near melting point
(C) between 1410°C and 1549°C
(D) between 910°C and 1400°C

Q13. Ferromagnetic alpha iron exists in temperature range of
(A) below 723°C
(B) 780 – 910°C
(C) 1400-1539°C
(D) above 1539°C.

Q14. Paramagnetic alpha iron changes to gamma iron at
(A) 770°C
(B) 910°C
(C) 1440°C
(D) 1539°C

Q15. 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) atomic change.

Q16. 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

Q17. The crystal structure of gamma iron is
(A) body centred cubic
(B) face centred cubic
(C) hexagonal close packed
(D) orthorhombic crystal

Q18. The crystal of alpha iron is
(A) body centred cubic
(B) face centred cubic
(C) hexagonal close packed
(D) cubic structure

Q19. The metallic structure of mild steel is
(A) body centred cubic
(B) face centred cubic
(C) hexagonal close packed
(D) orthorhombic crystal.

Q20. question
(A) option2
(B) option3
(C) option4
(D) answer