Question

Monel metal is a metallic alloy of copper and nickel with $5\%$ iron. It is used in making.
A.Locks
B.Strong boxes
C.Amirah
D.Motor parts

Answer 1

Monel alloy is a highly resistant alloy. It is better than stainless steel. It is very expensive. The Monel alloy can be used even under extreme conditions. Even with strong agents like acids and continuous flowing seawater it cannot get corroded.

Complete answer:
Monel metal is a binary alloy of the same proportions of nickel and copper with $5\%$ of iron. It is a cupronickel alloy (an alloy with $60\%$or more of copper contents). This alloy also contains a smaller amount of manganese, carbon, and silicon. It does not get corrode by any agent including rapidly flowing seawater. The Monel alloy is found naturally in the meteoritic nickel ore. This is a very expensive alloy. Because of this, its uses are limited. It is mostly used in those applications where it cannot be replaced with cheaper alternatives. Monel alloy is much stronger than pure Nickel. Being resistant against acids, oxygen, and water the Monel alloy is used for making locks.
Monel alloys are slightly magnetic at room temperature. They are widely used in the oil, chemical, and marine industries. It is much more efficient and expensive than stainless steel. It is commonly used in applications with highly corrosive conditions. Its mechanical properties are excellent at subzero temperatures. The alloy does not undergo a ductile-to-brittle transition even when cooled to the temperature of liquid hydrogen.

Thus the correct option is A.

Note:
Monel alloy is used in processing equipment such as fasteners, valves, shafts, fittings, pumps, and heat exchangers. It is also used as part of metal instruments and frames of eyeglasses. There are $6$types of Monel metal. All of them contain a higher percentage of nickel. With the small addition of titanium and aluminum its strength increases which is useful in aerospace applications.