NACE CP2 STUDENT MANUAL CHAPTER 5: STRAY CURRENTS
EXAM QUESTIONS AND ANSWERS WITH COMPLETE
SOLUTIONS VERIFIED GRADED A++
________ are currents through electrical paths other than the intended circuit.
A) Eddy currents
B) Stray currents
C) Direct currents
D) Alternating currents
b
A mitigation control bond should be designed to ______. (select all that apply)
A) carry the necessary current
B) restrict the current to the level required to mitigate the problem
C) keep the current going in one direction if necessary
D) return the portion on the interfered with structure to its pre-interference state
a, b, c, d
A mitigation bond may cause more problems under which of the following
conditions? (select all that apply)
,A) where the interfering structure bond point is more electropositive than the
interfered with structure.
B) where the interfering structure bond point is more electronegative than the
interfered with structure
C) where there are more than one, or changing current discharge points
D) where the interfering structure bond point potential varies from being more
electronegative to more electropositive than the interfered with structure.
a, c, d
AC voltages on pipelines do NOT result from:
A) resistive (conductive) coupling
B) electrostatic (capacitive) coupling
C) electromagnetic induction coupling
D) thermodynamic coupling
d
On a cathodically protected pipeline, AC corrosion can be expected at which
current densities? (select all that apply)
A) 30 mA/m^2
B) 10 A/m^2
C) 110 A/m^2
D) 200 A/m^2
c, d
, The AC voltage-to-ground on a section of pipeline near a powerline tends to be
__________.
A) highest where the power line and pipeline cross
B) highest where the power line and pipeline separate after a parallel section
C) highest at the ends of the overall pipeline with the parallel section in the
middle
D) the same along the pipeline/power line parallel section
b
Methods of making hazardous AC voltages safe include installing which of the
following? (select all that apply)
A) grounds at the discontinuities between powerline and
B) a bond to the steal powerline tower
C) a gradient mat or a grid around above ground structures
D) a remote ground away from the parallel section
a, c
A polarization cell is used to _________.
A) polarize the pipeline
B) polarize the electrical ground
C) provide DC coupling but block AC
D) provide AC coupling but block DC
EXAM QUESTIONS AND ANSWERS WITH COMPLETE
SOLUTIONS VERIFIED GRADED A++
________ are currents through electrical paths other than the intended circuit.
A) Eddy currents
B) Stray currents
C) Direct currents
D) Alternating currents
b
A mitigation control bond should be designed to ______. (select all that apply)
A) carry the necessary current
B) restrict the current to the level required to mitigate the problem
C) keep the current going in one direction if necessary
D) return the portion on the interfered with structure to its pre-interference state
a, b, c, d
A mitigation bond may cause more problems under which of the following
conditions? (select all that apply)
,A) where the interfering structure bond point is more electropositive than the
interfered with structure.
B) where the interfering structure bond point is more electronegative than the
interfered with structure
C) where there are more than one, or changing current discharge points
D) where the interfering structure bond point potential varies from being more
electronegative to more electropositive than the interfered with structure.
a, c, d
AC voltages on pipelines do NOT result from:
A) resistive (conductive) coupling
B) electrostatic (capacitive) coupling
C) electromagnetic induction coupling
D) thermodynamic coupling
d
On a cathodically protected pipeline, AC corrosion can be expected at which
current densities? (select all that apply)
A) 30 mA/m^2
B) 10 A/m^2
C) 110 A/m^2
D) 200 A/m^2
c, d
, The AC voltage-to-ground on a section of pipeline near a powerline tends to be
__________.
A) highest where the power line and pipeline cross
B) highest where the power line and pipeline separate after a parallel section
C) highest at the ends of the overall pipeline with the parallel section in the
middle
D) the same along the pipeline/power line parallel section
b
Methods of making hazardous AC voltages safe include installing which of the
following? (select all that apply)
A) grounds at the discontinuities between powerline and
B) a bond to the steal powerline tower
C) a gradient mat or a grid around above ground structures
D) a remote ground away from the parallel section
a, c
A polarization cell is used to _________.
A) polarize the pipeline
B) polarize the electrical ground
C) provide DC coupling but block AC
D) provide AC coupling but block DC
