Cathodic Protection Technologist
Certification Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationale 2026 Q&A| Instant
Download Pdf
1. In the context of Cathodic Protection applied to buried steel pipelines,
which statement best describes the fundamental principle by which
corrosion is mitigated when using impressed current systems?
A. The metal surface is coated to prevent electrolyte contact, eliminating all
electrochemical reactions
B. The structure is polarized to a more negative potential, forcing it to
become the cathode and suppressing anodic dissolution
C. Corrosion products are chemically neutralized by injected inhibitors,
stopping electron transfer
D. Oxygen is completely removed from the soil environment, stopping all
electrochemical activity
,B
The correct principle of impressed current cathodic protection is that
external current is applied to shift the metal’s potential in the negative
direction, making it the cathode so oxidation reactions are suppressed
while reduction reactions dominate.
2. A technologist measures a pipe-to-soil potential of -720 mV vs
Cu/CuSO₄ reference electrode. According to commonly accepted
criteria for steel in soil, what is the most appropriate interpretation of
this reading?
A. The structure is overprotected and at risk of hydrogen damage
B. The structure is inadequately protected and corrosion is likely ongoing
C. The structure meets the minimum protection criterion for cathodic
protection
D. The reading is invalid because Cu/CuSO₄ electrodes cannot be used in soil
B
A potential of -720 mV is generally more positive than the commonly
accepted -850 mV protection criterion for steel in soil, indicating
insufficient polarization and possible corrosion activity.
3. Which factor most significantly affects the current requirement in a
buried pipeline cathodic protection design?
,A. Ambient air humidity above ground
B. Pipe coating quality and holiday density
C. Pipe wall thickness variation
D. Steel grade tensile strength
B
Coating quality and defects directly determine exposed metal area; more
coating damage increases exposed surface requiring higher protective
current.
4. In galvanic (sacrificial anode) cathodic protection systems, which
material is most commonly used to protect steel structures in
seawater environments?
A. Copper
B. Aluminum alloy
C. Stainless steel
D. Cast iron
B
Aluminum alloys are widely used in seawater due to their favorable
electrochemical potential and high current capacity per unit mass.
5. Which phenomenon is most associated with overprotection in
cathodic protection systems?
, A. Graphitization of steel
B. Hydrogen embrittlement in high-strength steels
C. Increased anodic dissolution
D. Loss of coating adhesion due to oxidation
B
Excessively negative potentials can generate hydrogen atoms that diffuse
into high-strength steels, leading to embrittlement and cracking.
6. What is the primary function of a Cu/CuSO₄ reference electrode in
field surveys?
A. To supply protective current
B. To measure soil resistivity directly
C. To provide a stable reference potential for accurate voltage measurement
D. To neutralize stray current interference
C
Reference electrodes provide a stable electrochemical baseline against
which structure-to-electrolyte potentials are measured.
7. Which soil condition generally requires higher cathodic protection
current density?
A. High moisture clay soil
B. Dry sandy soil with high resistivity
Certification Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationale 2026 Q&A| Instant
Download Pdf
1. In the context of Cathodic Protection applied to buried steel pipelines,
which statement best describes the fundamental principle by which
corrosion is mitigated when using impressed current systems?
A. The metal surface is coated to prevent electrolyte contact, eliminating all
electrochemical reactions
B. The structure is polarized to a more negative potential, forcing it to
become the cathode and suppressing anodic dissolution
C. Corrosion products are chemically neutralized by injected inhibitors,
stopping electron transfer
D. Oxygen is completely removed from the soil environment, stopping all
electrochemical activity
,B
The correct principle of impressed current cathodic protection is that
external current is applied to shift the metal’s potential in the negative
direction, making it the cathode so oxidation reactions are suppressed
while reduction reactions dominate.
2. A technologist measures a pipe-to-soil potential of -720 mV vs
Cu/CuSO₄ reference electrode. According to commonly accepted
criteria for steel in soil, what is the most appropriate interpretation of
this reading?
A. The structure is overprotected and at risk of hydrogen damage
B. The structure is inadequately protected and corrosion is likely ongoing
C. The structure meets the minimum protection criterion for cathodic
protection
D. The reading is invalid because Cu/CuSO₄ electrodes cannot be used in soil
B
A potential of -720 mV is generally more positive than the commonly
accepted -850 mV protection criterion for steel in soil, indicating
insufficient polarization and possible corrosion activity.
3. Which factor most significantly affects the current requirement in a
buried pipeline cathodic protection design?
,A. Ambient air humidity above ground
B. Pipe coating quality and holiday density
C. Pipe wall thickness variation
D. Steel grade tensile strength
B
Coating quality and defects directly determine exposed metal area; more
coating damage increases exposed surface requiring higher protective
current.
4. In galvanic (sacrificial anode) cathodic protection systems, which
material is most commonly used to protect steel structures in
seawater environments?
A. Copper
B. Aluminum alloy
C. Stainless steel
D. Cast iron
B
Aluminum alloys are widely used in seawater due to their favorable
electrochemical potential and high current capacity per unit mass.
5. Which phenomenon is most associated with overprotection in
cathodic protection systems?
, A. Graphitization of steel
B. Hydrogen embrittlement in high-strength steels
C. Increased anodic dissolution
D. Loss of coating adhesion due to oxidation
B
Excessively negative potentials can generate hydrogen atoms that diffuse
into high-strength steels, leading to embrittlement and cracking.
6. What is the primary function of a Cu/CuSO₄ reference electrode in
field surveys?
A. To supply protective current
B. To measure soil resistivity directly
C. To provide a stable reference potential for accurate voltage measurement
D. To neutralize stray current interference
C
Reference electrodes provide a stable electrochemical baseline against
which structure-to-electrolyte potentials are measured.
7. Which soil condition generally requires higher cathodic protection
current density?
A. High moisture clay soil
B. Dry sandy soil with high resistivity
