81. Which metal is primarily used for making electrical contacts and connectors in high-power and high-temperature applications due to its high melting point and corrosion resistance?
a) Copper
b) Aluminum
c) Silver
d) Tantalum
82. What is the process of converting iron into steel by heating the iron in a controlled atmosphere to remove impurities called?
a) Refining
b) Smelting
c) Milling
d) Heat-treating
83. Which metal is commonly used for making electrical contacts and connectors in high-power applications due to its low electrical resistance and heat resistance?
a) Copper
b) Aluminum
c) Silver
d) Rhodium
84. What is the process of converting iron into steel by heating the iron with a controlled amount of carbon to adjust its carbon content called?
a) Refining
b) Smelting
c) Milling
d) Carbonization
85. Which metal is primarily used for making electrical contacts and connectors in electronic devices due to its low contact resistance and resistance to corrosion?
a) Copper
b) Aluminum
c) Silver
d) Rhodium
