151. What is corrosion?
a) The process of metal melting
b) The process of metal rusting
c) The process of metal solidification
d) The process of metal oxidation
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Correct answer: b) The process of metal rusting
Explanation: Corrosion refers to the process of metal deteriorating and forming rust when exposed to atmospheric conditions or other corrosive environments.
152. Which of the following is a common example of corrosion?
a) Formation of ice on metal surfaces
b) Discoloration of metal due to heat exposure
c) Peeling of paint on metal surfaces
d) Rusting of iron
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Correct answer: d) Rusting of iron
Explanation: Rusting of iron is a common example of corrosion where iron reacts with oxygen and water to form iron oxide (rust).
153. What is the primary cause of corrosion in metals?
a) Heat exposure
b) Mechanical stress
c) Moisture and oxygen exposure
d) Chemical exposure
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Correct answer: c) Moisture and oxygen exposure
Explanation: Corrosion occurs when metals are exposed to moisture (water) and oxygen, which react with the metal surface and initiate the corrosion process.
154. Which of the following is an effective method to prevent corrosion?
a) Increasing temperature
b) Reducing mechanical stress
c) Removing moisture
d) Applying protective coatings
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Correct answer: d) Applying protective coatings
Explanation: Applying protective coatings, such as paints, varnishes, or metal plating, forms a barrier between the metal surface and the corrosive environment, preventing direct contact and inhibiting corrosion.
155. Which metal is commonly used as a sacrificial anode to prevent corrosion in structures?
a) Copper
b) Aluminum
c) Zinc
d) Stainless steel
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Correct answer: c) Zinc
Explanation: Zinc is often used as a sacrificial anode in corrosion prevention systems, where it corrodes instead of the protected metal, sacrificing itself to protect the structure from corrosion.
156. Which corrosion prevention method involves the application of a protective layer on the metal surface?
a) Galvanization
b) Cathodic protection
c) Passivation
d) Protective coatings
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Correct answer: d) Protective coatings
Explanation: Protective coatings, such as paints, epoxy coatings, or galvanizing, create a barrier between the metal surface and the corrosive environment, preventing direct contact and corrosion initiation.
157. Which corrosion prevention method involves the use of impressed electrical current to protect the metal from corrosion?
a) Galvanization
b) Cathodic protection
c) Passivation
d) Protective coatings
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Correct answer: b) Cathodic protection
Explanation: Cathodic protection is a corrosion prevention technique where an impressed electrical current is used to create a cathodic (protective) potential on the metal surface, preventing corrosion.
158. Which corrosion prevention method involves the formation of a passive oxide layer on the metal surface?
a) Galvanization
b) Cathodic protection
c) Passivation
d) Protective coatings
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Correct answer: c) Passivation
Explanation: Passivation is a process that promotes the formation of a thin and protective oxide layer on the metal surface, enhancing its resistance to corrosion.
159. Which metal is commonly used for galvanization to prevent corrosion?
a) Copper
b) Aluminum
c) Zinc
d) Stainless steel
View Answer
Correct answer: c) Zinc
Explanation: Zinc is commonly used for galvanization, where a layer of zinc is applied to the metal surface through hot-dip galvanizing or electroplating, providing corrosion protection.
160. Which corrosion prevention method involves the use of inhibitors to reduce the rate of corrosion?
a) Galvanization
b) Cathodic protection
c) Passivation
d) Corrosion inhibitors
View Answer
Correct answer: d) Corrosion inhibitors
Explanation: Corrosion inhibitors are chemical compounds that can be added to the corrosive environment or applied to the metal surface to reduce the corrosion rate and protect the metal from deterioration.
