81. Beryllium bronze contains September 13, 2025 by Admin 60% copper and 40% beryllium 80% copper and 20% beryllium 97.75% copper and 2.25% beryllium 99% copper and 1% bery ✅ The correct answer is option C.
82. Duplex process of steel making is a combination of September 13, 2025 by Admin basic bessemer and acid open hearth processes acid bessemer and basic open hearth processes acid bessemer and acid open hearth processes basic bessemer and bas ✅ The correct answer is option B.
83. Wrought iron September 13, 2025 by Admin is a ductile material can be easily forged or welded cannot stand sudden and excessive shocks all of these ✅ The correct answer is option D.
84. Cast iron is a ductile material. September 13, 2025 by Admin Correct Incorrect ✅ The correct answer is option B.
85. Duralumin has better strength than Y-alloy at high temperature. September 13, 2025 by Admin TRUE FALSE ✅ The correct answer is option B.
86. The steel scrap added in the charge of cupola controls the grade of cast iron produced. September 13, 2025 by Admin Correct Incorrect ✅ The correct answer is option A.
87. Combined carbon in iron makes the metal September 13, 2025 by Admin soft and gives 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 ✅ The correct answer is option D.
88. The slow cooling of steel from the __________ results in a coarse grained structure. September 13, 2025 by Admin lower critical point upper critical point ✅ The correct answer is option B.
89. Nickel when added to copper improves September 13, 2025 by Admin machinability hardness hardness and strength strength and ductility ✅ The correct answer is option B.
90. The addition of copper to aluminium possesses maximum strength after heat treatment and age-hardening September 13, 2025 by Admin Correct Incorrect ✅ The correct answer is option A.