311. Which has the maximum melting point out of the following?
Steel
Cast iron
Stainless steel
Wrought iron
✅ The correct answer is option D.
Materials and Construction MCQs
312. Silicon percentage in iron castings to have maximum hardness should be about
0.3
0.5
0.8
2.5
✅ The correct answer is option C.
313. Which of the following comprises of hydrocarbons?
Mica flakes
Glass
Rubber
None of these
✅ The correct answer is option C.
314. Karbate is
A mixture of iron dust and saw dust
Carbon impregnated with resin (usually bakelite)
An acid resistant material
Both B and C
✅ The correct answer is option D.
315. The softest material just next to talc in the Mhos scale is
Quartz
Gypsum
Feldspar
Fluorite
✅ The correct answer is option B.
316. Which of the following is an alloy of nickel and copper?
Hastelloy
Duriron
Monel
Inconel
✅ The correct answer is option C.
317. Which metal is protected by the layer of its own oxide?
Iron
Silver
Calcium
Aluminium
✅ The correct answer is option D.
318. Muntz metal is a/an alloys of
Magnesium & tin
Ferrous material
Lead & tin
Copper & zinc
✅ The correct answer is option D.
319. Invar contains the highest percentage of
Vanadium
Iron
Tungsten
Cobalt
✅ The correct answer is option B.
320. Carbon percentage is the same in cast iron and
Wrought iron
Pig iron
Mild steel
High silicon (14%) iron
✅ The correct answer is option B.