261. Silicon when added to copper improves
machinability
hardness
hardness and strength
strength and ductility
✅ The correct answer is option C.
Engineering Materials MCQs
262. The type of space lattice found in gamma-iron is
face centred cubic space lattice
body centred cubic space lattice
close packed hexagonal space lattice
none of these
✅ The correct answer is option A.
263. The ability of a material to absorb energy in the plastic range is called
resilience
creep
fatigue strength
toughness
✅ The correct answer is option D.
264. Free carbon in iron makes the metal
soft and gives a coarse grained crystalline structure
soft and gives a fine grained crystalline structure
hard and gives a coarse grained crystalline structure
hard and gives a fine grained crystalline structure
✅ The correct answer is option A.
265. Ferrite and pearlite makes the steel soft and ductile.
Agree
Disagree
✅ The correct answer is option A.
266. The hardness and tensile strength in austenitic stainless steel can be increased by
hardening and cold working
normalising
martempering
full annealing
✅ The correct answer is option A.
267. The lower critical temperature
decreases as the carbon content in steel increases
increases as the carbon content in steel increases
is same for all steels
depends upon the rate of heating
✅ The correct answer is option C.
268. When the steel is normalised, its
yield point increases
ductility decreases
ultimate tensile strength increases
all of these
✅ The correct answer is option D.
269. Tungsten when added to steel __________ the critical temperature.
does not effect
lowers
raises
✅ The correct answer is option C.
270. The dieing down of a white flame during the operation of a bessemer converter indicates that the air is burning out silicon and manganese.
Yes
No
✅ The correct answer is option B.