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GEORGIA CORROSION CONTROL TECHNICIAN
EXAM QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS) Q & A 2026 |INSTANT
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1. What is corrosion? A. Mechanical wear of metals B. Chemical or electrochemical deterioration of metals C. Heat deformation of materials D. Magnetic breakdown of metals Rationale: Corrosion is primarily an electrochemical reaction between metal and environment. Correct answer: B 2. Which metal is most resistant to corrosion? A. Iron B. Copper C. Aluminum D. Gold Rationale: Gold is a noble metal and does not easily oxidize. Correct answer: D 3. The main cause of rusting in steel is:
A. Oxygen and moisture B. Nitrogen C. Carbon dioxide only D. Hydrogen gas Rationale: Rust forms due to oxidation of iron in presence of oxygen and water. Correct answer: A
4. What is galvanic corrosion? A. Corrosion due to heat B. Corrosion between dissimilar metals in contact C. Corrosion caused by paint failure D. Corrosion due to radiation Rationale: It occurs when two different metals form an electrochemical cell. Correct answer: B 5. In a galvanic cell, the anode is where: A. Reduction occurs B. Oxidation occurs C. No reaction occurs D. Metal is protected Rationale: Oxidation (metal loss) happens at the anode. Correct answer: B
Rationale: Electrolytes like saltwater accelerate corrosion. Correct answer: C
9. What is an electrolyte? A. A solid metal B. A non-conductive plastic C. A medium that conducts ions D. A vacuum space Rationale: Electrolytes allow ionic movement necessary for corrosion. Correct answer: C 10. The purpose of coating steel is to: A. Increase weight B. Prevent contact with environment C. Increase conductivity D. Make steel brittle Rationale: Coatings act as a barrier against oxygen and moisture. Correct answer: B 11. pH measures:
A. Temperature B. Acidity or alkalinity C. Electrical current D. Metal hardness Rationale: pH indicates hydrogen ion concentration. Correct answer: B
12. Which environment is most corrosive? A. Dry desert B. Fresh air C. Marine environment D. Vacuum Rationale: Saltwater accelerates electrochemical reactions. Correct answer: C 13. Corrosion is fastest in: A. Dry gases B. Wet electrolytic conditions C. Frozen metals D. Pure vacuum Rationale: Moisture enables ionic conduction. Correct answer: B
17. Which is NOT a form of corrosion? A. Pitting B. Galvanic C. Erosion D. Welding Rationale: Welding is a joining process, not corrosion. Correct answer: D 18. Pitting corrosion is: A. Uniform surface attack B. Localized hole formation C. Paint peeling only D. Surface heating Rationale: It creates small deep pits in metal surfaces. Correct answer: B 19. Rust is mainly composed of: A. Iron oxide B. Iron chloride C. Iron carbide D. Iron nitrate
Rationale: Rust is hydrated iron oxide. Correct answer: A
20. The cathode in corrosion: A. Loses electrons B. Gains electrons C. Dissolves metal D. Is always destroyed Rationale: Reduction occurs at the cathode. Correct answer: B 21. Which factor does NOT affect corrosion rate? A. Temperature B. Moisture C. Metal color D. Salinity Rationale: Color has no electrochemical effect. Correct answer: C 22. Sacrificial protection involves: A. Painting metal B. Using a more reactive metal
A. More noble metal B. Less reactive metal C. More reactive metal D. Both equally Rationale: The more reactive (anodic) metal corrodes first. Correct answer: C
26. Corrosion occurs due to: A. Pure mechanical force B. Electrochemical reactions C. Sound waves D. Light exposure only Rationale: Corrosion is driven by electrochemical processes. Correct answer: B 27. Which metal is commonly used for galvanizing steel? A. Copper B. Zinc C. Nickel D. Lead Rationale: Zinc provides sacrificial protection. Correct answer: B 28. The purpose of impressed current cathodic protection is to:
A. Increase corrosion B. Provide controlled electrical current C. Heat the structure D. Remove coating Rationale: External current protects metal structures. Correct answer: B
29. A reference electrode used in corrosion testing is: A. Steel rod B. Copper wire C. Copper/copper sulfate electrode D. Aluminum plate Rationale: Cu/CuSO₄ is standard for field measurements. Correct answer: C 30. Corrosion potential is measured in: A. Ohms B. Volts C. Amperes D. Watts Rationale: Electrical potential is measured in volts. Correct answer: B
34. Stress corrosion cracking requires: A. Only stress B. Only corrosion C. Stress and corrosive environment D. Low temperature only Rationale: Both mechanical stress and corrosion must be present. Correct answer: C 35. Crevice corrosion occurs in: A. Open surfaces B. Tight spaces C. Air only D. Clean polished metal Rationale: Oxygen depletion in gaps causes corrosion. Correct answer: B 36. The main function of protective coatings is to: A. Increase conductivity B. Prevent environmental contact C. Add weight D. Increase oxidation
Rationale: Coatings isolate metal from environment. Correct answer: B
37. Cathodic protection current is measured in: A. Ohms B. Volts C. Amperes D. Hertz Rationale: Current is measured in amperes. Correct answer: C 38. Which is a non-destructive testing method? A. Cutting sample B. Visual inspection C. Melting metal D. Grinding surface Rationale: Visual inspection does not damage structure. Correct answer: B 39. pitting corrosion is dangerous because it: A. Is visible easily B. Causes deep hidden damage
A. Increase corrosion B. Prevent current flow C. Increase conductivity D. Heat pipelines Rationale: They stop stray current movement. Correct answer: B
43. Which soil type is most corrosive? A. Dry sand B. Clay with moisture C. Gravel D. Rock Rationale: Moist clay retains electrolytes. Correct answer: B 44. Electrical resistance in corrosion systems is measured in: A. Volts B. Ohms C. Amperes D. Joules Rationale: Resistance is measured in ohms. Correct answer: B
45. Anode in cathodic protection system is usually: A. Protected structure B. Sacrificial material C. Plastic coating D. Paint layer Rationale: Anodes corrode instead of structure. Correct answer: B 46. Stray current corrosion is caused by: A. Gravity B. External electrical currents C. Heat only D. Wind Rationale: External currents leave pipelines or structures. Correct answer: B 47. Which is a corrosion inhibitor type? A. Acid only B. Organic and inorganic compounds C. Water only D. Oxygen only Rationale: Inhibitors reduce reaction rate. Correct answer: B
Rationale: Anode loses electrons (oxidation). Correct answer: B
51. The cathode reaction is: A. Oxidation B. Reduction C. Dissolution D. Evaporation Rationale: Cathode gains electrons. Correct answer: B 52. Corrosion in pipelines is commonly controlled by: A. Painting only B. Cathodic protection C. Heating D. Cooling Rationale: CP is standard pipeline protection. Correct answer: B 53. A dielectric coating is: A. Conductive layer B. Insulating layer
C. Metallic wire D. Salt layer Rationale: It prevents electrical flow. Correct answer: B
54. Corrosion rate is highest in: A. Dry air B. Saltwater environment C. Vacuum D. Frozen metal Rationale: Saltwater increases conductivity. Correct answer: B 55. Which is a physical corrosion protection method? A. Painting B. Alloying C. Sacrificial anodes D. Electroplating Rationale: Painting creates a physical barrier. Correct answer: A 56. Electroplating is used to:
