281. Duralumin is an alloy of
Aluminium, copper and manganese
Aluminium, nickel and silicon
Aluminium and nickel
None of these
✅ The correct answer is option A.
Materials and Construction MCQs
282. In the Contact process of sulphuric acid manufacture, 98% acid cooler is made of
Stainless steel
Cast iron
Lead lined steel
Rubber lined steel
✅ The correct answer is option B.
283. Hydrochloric acid is __________ corrosive to common metals.
Least
Not
Mildly
Highly
✅ The correct answer is option D.
284. Addition of tungsten to steel imparts
Magnetic properties
Cutting hardness
Corrosion resistance
Ductility
✅ The correct answer is option B.
285. Cementite is
Fe₃C chemically
A compound of carbon and iron
Characterised by an orthorhombic crystal structure
All of the above
✅ The correct answer is option D.
286. Dead mild steel, which contains 0.10 to 0.15 percent carbon is used for making
Shafts
Flanges
Gears
Shear blades
✅ The correct answer is option B.
287. Babbit metal is not a
Tin base alloy
White metal
Lead base alloy
Pure metal
✅ The correct answer is option D.
288. Most common stainless steel type 316, which is highly resistant to corrosion contains
16-13% Cr 10-14% Ni and 2-3% Mo
20-22% Cr, and 8-10% Ni
2-4% Cr, 22% NI and 2-4% Mo
None of these
✅ The correct answer is option A.
289. __________ does not contain copper as an alloying element,
Nichrome
Manganin
Perminivar
Monel metal
✅ The correct answer is option A.
290. Presence of high phosphorous in cast iron increases its
Fluidity
Melting point
Shrinkage
Tensile strength
✅ The correct answer is option A.