High silicon iron, silicon rubber, Kel-F and teflon
Mild steel and stainless steel
Cast iron, tin and aluminium
Copper, nickel and monel
✅ The correct answer is option A.
Materials and Construction MCQs
292. Which of the following heat treatment processes is used for softening the hardened material?
Normalising
Tempering
Annealing
None of these
✅ The correct answer is option B.
293. Invar used in thermocouples is an alloy of nickel and
Iron
Copper
Chromium
Lead
✅ The correct answer is option A.
294. A material capable of undergoing large permanent deformation, when subjected to compression is termed as
Malleable
Ductile
Brittle
None of these
✅ The correct answer is option A.
295. Which of the following is not a non-ferrous alloy?
Meehanite
Magnalium
Gun metal
Muntz metal
✅ The correct answer is option A.
296. The softest material in Mho’s scale (for measuring hardness) is
Talc
Gypsum
Rubber
None of these
✅ The correct answer is option A.
297. Light weight metallic alloy used in aircraft industry is
Aluminium
High silicon (14%) iron
Duralumin
Phosphor bronze
✅ The correct answer is option C.
298. Kel-F is a material, which is
Chemically known as polychlorotrifluor-oethylene (PTFE)
Having excellent chemical & high temperature resistance (upto 200°C)
Having elastomeric properties
All of the above
✅ The correct answer is option D.
299. Hot working of lead is carried out at
75° C
373° K
150° C
Room temperature
✅ The correct answer is option D.
300. Ability of a material to absorb energy in deformation in the plastic range is characterised as its
Ductility
Toughness
Creep
Resilience
✅ The correct answer is option B.