1. Ductility of a material can be defined as
(a) ability to undergo large permanent deformations in compression
(b) ability to recover its original form
(c) ability to undergo large permanent deformations in tension
(d) all of the above
(e) none of the above.
Ans: c
2. Malleability of a material can be defined as
(a) ability to undergo large permanent deformations in compression
(b) ability to recover its original form
(c) ability to undergo large permanent deformations in tension
(d) all of the above
(e) none of the above.
Ans: a
3. In compression, a prism of brittle material will break
(a) by forming a bulge (l>) by shearing along oblique plane
(c) in direction perpendcular to application of load
(d) by crushing into thousands of pieces
(e) none of the above.
Ans: b
4. The ability of a material to resist softening at high temperature is known as
(a) creep
(b) hot tempering
(c) hot hardness
(d) fatigue
(e) super hardening.
Ans: c
5. Mild steel belongs to the following category
(a) low carbon steel
(b) medium carbon steel
(c) high carbon steel
(d) alloy steel
(e) special steel.
Ans: a
6. The ultimate tensile strength of low carbon steel by working at a high strain rate will
(a) decrease
(b) increase
(c) remain constant
(d) first increase and then decrease
(e) first decrease and then increase.
Ans: b
7. Slow plastic defoliation of metals under a constant stress is known as
(a) creep
(b) fatigue
(c) endurance
(d) plastic deformation
(e) non-plastic deformation.
Ans: a
8. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to l00°C will
(a) increase
(b) decrease
(c) remain same
(d) first increase and then decrease
(e) show unpredictable behavior.
Ans: a
9. The number of electrons in 1 cm3 of metal would be of the order of
(a) 1010
(b)TO16
(c) 1022
(d) 1040
(e) 1052
Ans: c
10. Stress relaxation is- the phenomenon
(a) in which parts are not loaded
(b) in which stress remains constant on increasing load
(c) in which deformation tends to loosen the joint and produces a stress reduced
(d) stress reduces on increasing load
(e) none of the above.
Ans: c
ll. The elastic stress strain behavior of rubber is
(a) linear
(b) non-linear
(c) plastic
(d) no fixed relationship
(e) unpredictable behavior.
Ans: b
12. 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
(e) density throughout.
Ans: a
13. 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 grow bigger in size
(e) at which crystals are destroyed on heating.
Ans: b
14. 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
(e) none of the above.
Ans: a
15. Delta iron occurs at temperature of
(a) room temperature
(b) above melting point
(c) between 1400°C and 1539°C
(c) between 910°C and 1400°C
(e) none of the above.
Ans: c
16. 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
(e) none of the above.
Ans: b
17. 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
(e) above 1000°C.
Ans: a
18. Which of the following constituents of steels is softest and least strong
(a) austenite
(b) pearlite
(c) ferrite
(d) cementlte
(e) bainite.
Ans: c
19. 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 centered cubic a-iron and face centered cubic a-iron
(d) alpha iron, gamma from and delta iron
(e) none of the above.
Ans: d
20. 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
(e) none of the above.
Ans: a
21. Pure iron is the structure of
(a) ferrite
(b) pearlite
(c) anstenite
(d) ferrite and cementite
(e) ferrite and pearlite.
Ans: a
22. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
(a) 770°C
(b) 910°C
(c) 1050°C
(d) below recrystallization temperature
(e) above recrystallization temperature.
Ans: a
23. 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
(e) none of the above.
Ans: d
24. Ferromagnetic alpha iron exists in temperature range of
(a) below 723°C
(b) 770 – 910°C
(c) 910-1440°C
(d) 1400-1539°C
(e) above 1539°C.
Ans: a
25. Paramagnetic alpha iron changes to gamma iron at
(a) 770°C
(b) 910°C
(c) 1440°C
(d) 1539°C
(e) none of the above.
Ans: b