NACE CP2 ACTUAL FINALS ANSWERS AND
QUESTIONS SURE A+
✔✔an electrolytic couple between a pipe and a casing
A. shields CP current from the pipeline.
B. causes a high current demand due to the casing.
C. allows CP current to access the pipeline.
D. causes corrosion on the outside of the casing - ✔✔C. allows CP current to access
the pipeline
✔✔With sufficient current applied to a pipeline which has an electrolytic couple to the
casing, the potentials will
A. shift electropositively on the outside of the casing
B. shift electropositively on the pipe inside the casing
C.shift electropositively on the inside of the casing
D. will be the same on the pipe and the casing - ✔✔C.shift electropositively on the
inside of the casing ?????
✔✔A stray current is a current that
A. goes back and forth
B. goes in an unintended path
C. goes only to a pipeline
D. does not complete a circuit - ✔✔B. goes in an unintended path
✔✔a mitigation control bond should be designed to
I. carry the necessary current.
II. restrict the current to that required to mitigate the problem.
III. keep the current going in one direction if necessary
IV. return the potential on the interfered with structure to its pre-interference state - ✔✔I,
II, III, and IV
, ✔✔a mitigation bond may cause more problems under which of the following
conditions?
I where the interfering structure bond point is more electropositive than the interfered
with structure.
II. where the interfering structure bond point is more electronegative than the interfered
with structure
III. where there are more than one, or changing, current discharge points
IV. where the interfering structure bond point potential varies from being more
electronegative to more electropositive than the interfered with structure. - ✔✔I, III, and
IV only
?????
✔✔AC voltages on pipelines do NOT result from
A. resistive (conductive) coupling
B. electrostatic (capacitive) coupling
C. electromagnetic induction coupling
D. thermodynamic coupling - ✔✔D. thermodynamic coupling
✔✔on a cathodically protected pipeline, AC corrosion can be expected at which current
densities?
I. 20 mA/m^2
II. 10 A/m^2
III. 110 A/m^2
IV. 200 A/m^2 - ✔✔III and IV only
i ac < 20 A/m^2 ..... no corrosion
20 A/m^2 < i ac < 100 A/m^2 ... corrosion unpredictable
i ac > 100 A/m^2 .... corrosion expected
✔✔The AC voltage-to-ground on a section of pipeline paralleling AND crossing a power
line tends to be highest
I. where the power line and pipeline cross
II. point where the power line and pipeline seperate
III. A gradient mat or a grid around above ground structures
IV. A remote ground away from the parallel section - ✔✔I and II only
✔✔Methods of lowering hazardous AC voltages include installing which of the
following?
QUESTIONS SURE A+
✔✔an electrolytic couple between a pipe and a casing
A. shields CP current from the pipeline.
B. causes a high current demand due to the casing.
C. allows CP current to access the pipeline.
D. causes corrosion on the outside of the casing - ✔✔C. allows CP current to access
the pipeline
✔✔With sufficient current applied to a pipeline which has an electrolytic couple to the
casing, the potentials will
A. shift electropositively on the outside of the casing
B. shift electropositively on the pipe inside the casing
C.shift electropositively on the inside of the casing
D. will be the same on the pipe and the casing - ✔✔C.shift electropositively on the
inside of the casing ?????
✔✔A stray current is a current that
A. goes back and forth
B. goes in an unintended path
C. goes only to a pipeline
D. does not complete a circuit - ✔✔B. goes in an unintended path
✔✔a mitigation control bond should be designed to
I. carry the necessary current.
II. restrict the current to that required to mitigate the problem.
III. keep the current going in one direction if necessary
IV. return the potential on the interfered with structure to its pre-interference state - ✔✔I,
II, III, and IV
, ✔✔a mitigation bond may cause more problems under which of the following
conditions?
I where the interfering structure bond point is more electropositive than the interfered
with structure.
II. where the interfering structure bond point is more electronegative than the interfered
with structure
III. where there are more than one, or changing, current discharge points
IV. where the interfering structure bond point potential varies from being more
electronegative to more electropositive than the interfered with structure. - ✔✔I, III, and
IV only
?????
✔✔AC voltages on pipelines do NOT result from
A. resistive (conductive) coupling
B. electrostatic (capacitive) coupling
C. electromagnetic induction coupling
D. thermodynamic coupling - ✔✔D. thermodynamic coupling
✔✔on a cathodically protected pipeline, AC corrosion can be expected at which current
densities?
I. 20 mA/m^2
II. 10 A/m^2
III. 110 A/m^2
IV. 200 A/m^2 - ✔✔III and IV only
i ac < 20 A/m^2 ..... no corrosion
20 A/m^2 < i ac < 100 A/m^2 ... corrosion unpredictable
i ac > 100 A/m^2 .... corrosion expected
✔✔The AC voltage-to-ground on a section of pipeline paralleling AND crossing a power
line tends to be highest
I. where the power line and pipeline cross
II. point where the power line and pipeline seperate
III. A gradient mat or a grid around above ground structures
IV. A remote ground away from the parallel section - ✔✔I and II only
✔✔Methods of lowering hazardous AC voltages include installing which of the
following?
