CP 1 Practice Questions
These CP 1 practice questions focus on cathodic protection fundamentals, corrosion basics, terminology, and basic field understanding.
Study Focus
CP 1-level study should emphasize corrosion cells, anodes, cathodes, electrolytes, metallic paths, galvanic CP, impressed current CP, reference electrodes, and basic measurements.
How to Use These Questions
Answer each question before checking the explanation. The goal is not memorizing letters. The goal is understanding why the correct answer is correct and why the other choices are wrong.
Practice Questions
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In a corrosion cell, where does metal loss occur?
- At the cathode
- At the anode
- In the voltmeter
- In the reference electrode
Answer: B. Metal loss occurs at the anode where oxidation occurs.
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Which four elements are required for electrochemical corrosion?
- Anode, cathode, electrolyte, metallic path
- Rectifier, anode, test station, coating
- Voltage, resistance, coating, pipe
- Soil, water, oxygen, paint
Answer: A. A corrosion cell requires an anode, cathode, electrolyte, and metallic path.
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What is the purpose of cathodic protection?
- To make the protected structure act more anodic
- To eliminate all corrosion permanently
- To reduce corrosion by making the structure act more cathodic
- To remove the electrolyte from the soil
Answer: C. CP reduces corrosion by forcing the protected structure in the cathodic direction.
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Which system uses sacrificial anodes without an external power source?
- Impressed current CP
- Galvanic CP
- AC mitigation
- Continuity bonding only
Answer: B. Galvanic CP uses sacrificial anodes as the current source.
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Which device is commonly used as the DC power source in an impressed current CP system?
- Reference electrode
- Coupon
- Rectifier
- Insulating flange kit
Answer: C. Rectifiers convert AC power to DC output for impressed current CP systems.
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What does a reference electrode provide during CP testing?
- A stable comparison point for potential measurements
- Protective current to the structure
- Coating repair material
- AC power to the rectifier
Answer: A. A reference electrode provides a stable comparison point for measuring structure-to-electrolyte potentials.
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Why does a coating help a CP system?
- It increases the required current
- It reduces exposed metal area and lowers current demand
- It replaces the need for all testing
- It makes soil nonconductive
Answer: B. Coatings reduce the metal area exposed to the electrolyte, which lowers CP current demand.
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What is the electrolyte in a buried pipeline corrosion cell?
- The steel pipe wall only
- The soil or moisture surrounding the pipe
- The rectifier cabinet
- The test lead insulation
Answer: B. Soil and moisture act as the electrolyte for buried pipeline corrosion cells.
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Why is rectifier output alone not proof of adequate protection?
- Because rectifiers never produce DC current
- Because output does not prove current reaches every required structure location
- Because rectifiers are only used with galvanic systems
- Because amperage is never measured in CP work
Answer: B. Rectifier output confirms DC output, not full structure protection or current distribution.
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What happens to galvanic anodes as they operate?
- They are consumed
- They become reference electrodes
- They stop all current flow
- They convert DC to AC
Answer: A. Galvanic anodes corrode sacrificially and are consumed over time.