51. Silicon in cast iron
makes the iron soft and easily machinable
increases hardness and brittleness
makes the iron white and hard
aids fusibility and fl
✅ The correct answer is option A.
Engineering Materials MCQs
52. In the lower part of the blast furnace (zone of fusion), the temperature is
400° to 700°C
800°C to 1000°C
1200°C to 1300°C
1500°C to 1700°C
✅ The correct answer is option C.
53. Gamma-iron occurs between the temperature range of
400°C to 600°C
600°C to 900°C
900°C to 1400°C
1400°C to 1530°C
✅ The correct answer is option C.
54. The alloying element which reduces the formation of iron sulphide in steel is
chromium
nickel
vanadium
manganese
✅ The correct answer is option D.
55. In high speed steels, vanadium adds to the property of red hardness and tungsten and chromium add to high wear resistance.
TRUE
FALSE
✅ The correct answer is option A.
56. The process of inducing carbon to __________ carbon steels in order to give it a hard surface is known as carburising.
low
medium
high
✅ The correct answer is option A.
57. Iron-carbon alloys containing 4.3% carbon are known as hypo-eutectic cast irons.
Correct
Incorrect
✅ The correct answer is option B.
58. Silicon bronze contains
60% copper, 35% zinc and 5% manganese
88% copper, 10% tin and 2% zinc
96% copper, 3% silicon and 1% manganese
76% copper, 20% silico
✅ The correct answer is option C.
59. The austenite is a solid solution of carbon or iron carbide in gamma-iron.
Correct
Incorrect
✅ The correct answer is option A.
60. The ability of a material to undergo large permanent deformation with the application of a tensile force, is called ductility.
Correct
Incorrect
✅ The correct answer is option A.