Cathodic Protection Tester Certification
Exam Practice Questions And Correct
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1. In cathodic protection systems, the primary purpose of applying a
protective current to a buried steel pipeline is best described as:
A. Increasing the pipe’s electrical resistance to reduce current flow
B. Forcing the metal surface to become anodic to accelerate controlled
corrosion
C. Shifting the pipe potential to a more negative value to suppress oxidation
reactions
D. Eliminating soil moisture to prevent electrochemical activity
The correct principle of cathodic protection is to make the structure more
negatively charged so that it behaves as a cathode, thereby reducing or
stopping anodic metal loss through oxidation reactions.
, 2. Which reference electrode is most commonly used for measuring the
potential of underground pipelines in field cathodic protection testing?
A. Silver/Silver Chloride electrode
B. Copper/Copper Sulfate electrode
C. Zinc reference electrode
D. Hydrogen gas electrode
The Copper/Copper Sulfate electrode is the standard field reference
electrode for soil environments due to its stability, portability, and widely
accepted calibration for pipeline potential measurements.
3. A pipe-to-soil potential reading of -0.85 V (Cu/CuSO₄) generally
indicates:
A. Complete corrosion failure of the pipeline
B. Adequate cathodic protection under common industry criteria
C. Overprotection causing hydrogen damage
D. No electrochemical activity occurring
A reading of -0.85 V or more negative is widely used as a minimum
criterion indicating sufficient cathodic protection for steel pipelines in soil.
4. Which factor most directly influences soil resistivity in cathodic
protection design?
A. Pipe diameter
B. Soil moisture content
,C. Steel grade
D. Coating thickness
Soil moisture significantly affects resistivity because water content controls
ionic conduction, making it a key design parameter in cathodic protection
systems.
5. The function of a rectifier in an impressed current cathodic protection
system is to:
A. Convert DC to AC for grounding purposes
B. Increase soil resistivity around the pipeline
C. Convert AC power supply into controlled DC output
D. Measure pipeline corrosion rate
A rectifier converts alternating current to direct current, which is required
to drive protective current in impressed current cathodic protection
systems.
6. An anode in a cathodic protection system is best described as:
A. The protected structure receiving electrons
B. The electrode where oxidation occurs
C. A non-conductive barrier layer
D. A device that measures soil potential
The anode is the site of oxidation reactions where metal loss occurs,
supplying electrons that flow to protect the cathode (structure).
, 7. The “IR drop” in pipe-to-soil measurements refers to:
A. Increase in pipe diameter due to corrosion
B. Voltage loss caused by current flow through soil resistance
C. Temperature variation along pipeline length
D. Magnetic interference from nearby power lines
IR drop is the voltage error introduced when current flows through soil
resistance, affecting accuracy of true pipe-to-soil potential readings.
8. Which coating defect condition most increases cathodic protection
current demand?
A. Smooth, intact coating
B. High dielectric strength coating
C. Holiday (discontinuity) in coating
D. Multi-layer fusion bonded epoxy
Coating holidays expose bare metal to soil, significantly increasing current
demand because the exposed steel requires direct cathodic protection.
9. Stray current corrosion is most commonly associated with:
A. High soil alkalinity
B. Nearby DC transit or welding systems
C. Low pipeline diameter
D. Excessively thick coatings
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. In cathodic protection systems, the primary purpose of applying a
protective current to a buried steel pipeline is best described as:
A. Increasing the pipe’s electrical resistance to reduce current flow
B. Forcing the metal surface to become anodic to accelerate controlled
corrosion
C. Shifting the pipe potential to a more negative value to suppress oxidation
reactions
D. Eliminating soil moisture to prevent electrochemical activity
The correct principle of cathodic protection is to make the structure more
negatively charged so that it behaves as a cathode, thereby reducing or
stopping anodic metal loss through oxidation reactions.
, 2. Which reference electrode is most commonly used for measuring the
potential of underground pipelines in field cathodic protection testing?
A. Silver/Silver Chloride electrode
B. Copper/Copper Sulfate electrode
C. Zinc reference electrode
D. Hydrogen gas electrode
The Copper/Copper Sulfate electrode is the standard field reference
electrode for soil environments due to its stability, portability, and widely
accepted calibration for pipeline potential measurements.
3. A pipe-to-soil potential reading of -0.85 V (Cu/CuSO₄) generally
indicates:
A. Complete corrosion failure of the pipeline
B. Adequate cathodic protection under common industry criteria
C. Overprotection causing hydrogen damage
D. No electrochemical activity occurring
A reading of -0.85 V or more negative is widely used as a minimum
criterion indicating sufficient cathodic protection for steel pipelines in soil.
4. Which factor most directly influences soil resistivity in cathodic
protection design?
A. Pipe diameter
B. Soil moisture content
,C. Steel grade
D. Coating thickness
Soil moisture significantly affects resistivity because water content controls
ionic conduction, making it a key design parameter in cathodic protection
systems.
5. The function of a rectifier in an impressed current cathodic protection
system is to:
A. Convert DC to AC for grounding purposes
B. Increase soil resistivity around the pipeline
C. Convert AC power supply into controlled DC output
D. Measure pipeline corrosion rate
A rectifier converts alternating current to direct current, which is required
to drive protective current in impressed current cathodic protection
systems.
6. An anode in a cathodic protection system is best described as:
A. The protected structure receiving electrons
B. The electrode where oxidation occurs
C. A non-conductive barrier layer
D. A device that measures soil potential
The anode is the site of oxidation reactions where metal loss occurs,
supplying electrons that flow to protect the cathode (structure).
, 7. The “IR drop” in pipe-to-soil measurements refers to:
A. Increase in pipe diameter due to corrosion
B. Voltage loss caused by current flow through soil resistance
C. Temperature variation along pipeline length
D. Magnetic interference from nearby power lines
IR drop is the voltage error introduced when current flows through soil
resistance, affecting accuracy of true pipe-to-soil potential readings.
8. Which coating defect condition most increases cathodic protection
current demand?
A. Smooth, intact coating
B. High dielectric strength coating
C. Holiday (discontinuity) in coating
D. Multi-layer fusion bonded epoxy
Coating holidays expose bare metal to soil, significantly increasing current
demand because the exposed steel requires direct cathodic protection.
9. Stray current corrosion is most commonly associated with:
A. High soil alkalinity
B. Nearby DC transit or welding systems
C. Low pipeline diameter
D. Excessively thick coatings
