با شرکت در آزمون حفاظت کاتدیک سازه های دریایی انجمن NACE سال 2007 خودرا بيازماييد
CP2 Marine Final Exam Version 1A, January, 2007
CP2-CATHODIC
PROTECTION TECHNICIAN
Marine
FINAL WRITTEN EXAM
2.5 HOUR MAXIMUM
OPEN BOOK
100 QUESTIONS
(7/1/05 - time was increased from 2 hrs to 2.5 hrs to allow ample time for ADA and ESL
requests. No additional time should be granted for special requests.)
CP2 Marine Final Exam Version 1A, January, 2007
NACE INTERNATIONAL
All NACE exams are the sole possession of NACE International. Any copying or sharing of any
portions of the exam(s) without the express written consent of NACE International is prohibited.
In the event of suspected cheating, NACE has the right to invalidate exam results, fail the
applicant and prohibit applicant from pursing any NACE certification or taking a NACE course/
exam for a period of five (5) years or take such other action as provided for by NACE policies and
procedures. Determinations regarding cheating shall be made in accordance with NACE policies
and procedures, which NACE may amend in its sole discretion. Applicants acknowledge and
agree that they are subject to these terms and conditions when taking any NACE exam.
I have read and understood the information stated above.
____________________________________________________
Applicant’s Signature
____________________________________________________
Please PRINT Name
___________________________________________
Date
CP2 Marine Final Exam Version 1A, January, 2007
Cathodic Protection Technician-Marine
ATTESTATION
I hereby:
۱. Recognize and acknowledge that the proper control of cathodic protection can be critical to
the safety and welfare of the general public and industrial facilities.
2. Recognize and acknowledge that the control of cathodic protection is obligatory to maximize
conservation of our material resources, to reduce economic losses, and to protect the environment.
3. Recognize and acknowledge that the entire field of cathodic protection and its control encompasses
the application of the knowledge and experience of many diverse disciplines and levels
of technical competence which must often be consulted.
4. Recognize and acknowledge that only through continual association and cooperation with
others in this field can the safest and most economical solutions be found to the many
cathodic protection problems.
5. Recognize and acknowledge that the quality of my work reflects on the entire profession of
corrosion control.
For these reasons I:
1. Agree to give first consideration in my cathodic protection work to public safety and welfare
and to protection of the environment.
2. Agree to apply myself with diligence and responsibility to the cathodic protection work that
lies within my area of competence.
3. Agree to pursue my work with fairness, honesty, integrity and courtesy, ever mindful of the
best interests of the public, my employer, and of fellow workers.
4. Agree to not represent myself to be proficient or make recommendations in phases of cathodic
protection work in which I am not qualified by knowledge and experience.
5. Agree to avoid and discourage untrue, sensational, exaggerated, and/or unwarranted statements
regarding my work in oral presentations, written text, and/or advertising media.
6. Agree to treat as confidential my knowledge of the business affairs and/or technical process of
clients, employers, or customers when their interests so require.
7. Agree to inform clients or employers of any business affiliations, interests, and/or connections
which might influence my judgment.
8. Agree to uphold, foster and contribute to the achievement of the objectives of NACE International.
I understand that my failure to comply with these requirements could result in disciplinary
action.
____________________________________________________
Applicant’s Signature
____________________________________________________
Please PRINT Name
___________________________________________
Date
Name: __________________________ Date: ___________________
CP2 Marine Final Exam Page 1 of 22 Version 1A, January, 2007
CP2-Cathodic Protection
Technician-Marine
Final Exam
1. Iron anodes can be used for the protection of ______________
a)copper alloys.
b)aluminum.
c)magnesium.
d)zinc.
2. The advantages of impressed current cathodic protection (ICCP) systems include
which of the following?
I. Low hull profile reducing drag and noise.
II. Remote monitoring of system operation.
III.Does not require log keeping.
IV.System operation automation.
a)I, II, and III only
b)I, II, III, and IV
c)I, II, and IV only
d)I and IV only
3. Hull cathode (current) demand is a functi اااا...م۷۶۹اا
I. coating condition.
II. surface preparation method.
III.resistivity of the water.
IV.hull speed.
a)I, III, and IV only
b)II and IV only
c)I and IV only
d)I, II, III, and IV
4. How are ship’s hull reference cells installed?
a)Adjacent to each anode(s) powered by the same controller-power supply.
b)Approximately halfway between anode(s) powered by the same controllerpower
supply.
c)Randomly between anode(s) powered by the same controller-power supply.
d)Adjacent to every third anode(s) powered by the same controller-power
supply.
5. The presence of bleaching of the coatings on a ships hull is an indication of an
ICCP system that is________________
a)working properly.
b)shorted out.
c)providing too much current.
d)providing too little current.
6. Rates of dezincification of brass are directly related to___________
I. increased content of zinc.
II. increased water temperature.
III.increased chloride concentration.
IV.decreased water speed.
a)I, II, and III only
b)I, II, III, and IV
c)I, II, and IV only
d)I and IV only
7. The three conditions that need to exist for hydrogen embrittlement of titanium are
I. metal temperatures above 80°C.
II. metal temperatures below 80°C.
III.a mechanism for generating hydrogen.
IV.solution pH less than3 or greater than 12.
a)I, II, and III only
b)I, II, III, and IV
c)I, III, and IV only
d)I and IV only
8. Currents through electrical paths other than the intended circuit are referred to
as__________________
a)telluric currents.
b)stray currents.
c)galvanic currents.
d)corrosion currents.
9. During a waterborne(seawater) ship hull potential survey, all readings were found
to be more electropositive than –0.55 V (re Ag/AgCl). This means/
requires__________________
I. the ICCP system is operating correctly.
II. there is stray current affecting system.
III.the ICCP system is not operating.
IV.notification the Chief Engineer.
a)I and IV only
b)I and III only
c)II and III only
d)II, III, and IV only
10. When conducting a waterborne ship hull potential survey, in order to obtain meter
deflection, the negative terminal of the voltmeter is connected
to________________________
a)a Ag/AgCl reference cell.
b)a Cu/CuSO4 reference cell.
c)the ship’s hull.
d)convenient metal object on pier.
11. __________________ are detrimental to aluminum hull ships do to the alkaline
conditions generated.
a)Potentials more electronegative than +1.1
b)Potentials more electronegative than +0.55
c)Potentials more electronegative than –0.55
d)Potentials more electronegative than –1.1
12. When conducting a waterborne ship hull potential survey, measurements are
recorded________________________
I. at 125-foot intervals.
II. at 25-foot intervals.
III.with reference cell 10-15 feet below waterline.
IV.with the reference cell just below the water surface.
a)I and IV only
b)I and III only
c)II and III only
d)II and IV only
13. The back-EMF test is used to determine whether there is a problem with
___________________________
a)the hull-mounted reference cell.
b)the ICCP power supply.
c)the hull-mounted anode.
d)the ICCP controller.
14. A __________________reading during a back-EMF test indicates a problem, such
as shorted lead
a)low/ less than1.0 V.
b)high/more than 5.0 V.
c)low/1.0 to 2.0 V.
d)high/2.0 to 5.0 V.
15. During ICCP System troubleshooting, the anode current on the power supply
ammeter suddenly increases while the control reference electrode check indicates
0.80 to 0.85 V. This indicates which of the following conditions?
I. Ship speed increasing
II. Ship speed decreasing
III.Paint has been removed from hull
IV.Ship moving from fresh to saltwater
a)I or III only
b)I and IV only
c)I, III or IV only
d)II, III or IV only
16. What is the minimum number of galvanic anodes required to protect a 2000 square
foot portion of the underwater hull (12% coating damage, design current demand
is 15 mA/ft2, design anode output is 420 mA)?
a)4
b)9
c)12
d)15
17. Overprotection has a detrimental effect on ____________
a)atmospheric materials.
b)aliphatic materials.
c)amphoteric materials.
d)aqueous materials.
18. A Galvanic Series represents________________-
a)a ranking of metals and alloys based on actual measured potentials in any
environment.
b)a ranking of metals and alloys based on actual measured potentials in a
specific environment.
c)a ranking of metals and alloys based on theoretical potentials in any
environment.
d)a ranking of metals and alloys based on theoretical potentials in a specific
environment.
19. __________ metal is one that is active in the EMF series but which corrodes at a
much lower rate than one would predict.
a)A passive
b)An immune
c)An amphoteric
d)An active
20. The most common marine alloy that exhibits passive behavior in aerated seawater
is________________________
a)mild steel.
b)zinc.
c)stainless steel.
d)aluminum.
21. The disadvantages of galvanic cathodic protection systems include__________
I. turbulent flow and noise is increased on ships.
II. hull drag and increased weight cause increased fuel consumption.
III.the protection current is not controllable.
IV.external source of power required.
a)I, II, and III only
b)I, II, III, and IV
c)I, II, and IV only
d)II and IV only
22. __________ monitors signals from the reference electrode and controls power
supply outputs that maintain the hull at preset potentials.
a)The reference electrode
b)The shaft ground
c)The dielectric shield
d)The controller
23. The dielectric shield is a high-solids epoxy coating applied to the hull around each
anode that prevents________________
a)bleaching and aids in wider current distribution.
b)shorting of current to hull and aids in wider current distribution.
c)shorting of current to hull and aids in minimizing current distribution.
d)calcareous deposits and aids in wider current distribution.
24. NACE Standard RP0176 addresses
a)corrosion control of steel fixed offshore structures associated with petroleum
production.
b)corrosion control of underground pipelines.
c)cathodic protection of aboveground storage tanks.
d)cathodic protection of ships.
25. According to NACE Standard RP0176, the most common for evaluating the CP
level is
a)to measure the potential between the structure and a suitable reference
electrode.
b)to determine depolarization rate.
c)to measure cathodic current.
d)to measure anodic current.
26. Exposed areas of the steel hull or other anodic materials tend to provide protection
to copper alloys and experience accelerated corrosion. The most common
examples of this situation are
I. the large areas of copper alloy associated with the ship’s propellers.
II. areas adjacent to ICCP anodes.
III.uncoated copper/nickel alloy piping in tanks.
IV.areas associated with sonar domes.
a)I, II, and III only
b)I and III only
c)I, II, and IV only
d)II and IV only
27. Aluminum alloys that have been extruded or otherwise worked heavily, with a
microstructure of elongated, flattened grains, are particularly prone
to__________________
a)selective leaching.
b)crevice corrosion.
c)exfoliation corrosion.
d)general corrosion.
28. Normal operating procedures require maintaining a Cathodic Protection Log of the
ICCP system operation on NAVSEA Form 9633/1. Readings are required
__________ and logs are submitted to NAVSEA _________
a)monthly/annually.
b)daily/weekly.
c)hourly/monthly.
d)daily/monthly.
29. An example of dynamic stray current on a ship is__________
a)CP current from a shore facility.
b)CP current from another ship.
c)an improperly grounded welding machine.
d)a properly grounded welding machine.
30. Structure-to-electrolyte potential profile surveys are used to____________
I. determine the effectiveness of cathodic protection.
II. determine remaining life of anodes.
III.locate stray currents.
IV.locate coating holidays.
a)I, II, and IV only
b)I and III only
c)I, III, and IV only
d)I, II, III, and IV
31. A waterborne ship hull potential survey determined that all potentials ranged from
–0.75 to –0.95 V (re Ag/AgCl). The action required is which of the choices
below?
a)Investigate for source of stray current.
b)Reduce voltage to anodes.
c)Increase voltage to anodes.
d)None.
32. During a drydock hull inspection after a ship has been waterborne for 5 years,
several galvanic anodes show no loss of material. This situation
indicates____________________
a)normal conditions.
b)proper operation of the anode.
c)problems with anode attachment or material.
d)the need to remove all galvanic anodes.
33. ____________will typically occur in the stern of a ship because of the bronze or
CRES alloy propellers and shafts
a)Less negative hull potential
b)A positive hull potential
c)Less CP current demand
d)Fewer anodes
34. The concept of cathodic protection involves reducing the potential difference
between the local ______
a)steel and copper sites to zero, resulting in zero corrosion current flow.
b)steel and copper sites to zero, resulting in increased corrosion current flow.
c)anodic and cathodic sites to zero, resulting in zero corrosion current flow.
d)anodic and cathodic sites to zero, resulting in increased corrosion current
flow.
35. In the event that coupling of dissimilar metals is required, what is the desired
situation from a corrosion control point of view?
a)Large anode/small cathode
b)Small anode/large cathode
c)Small coated anode/large cathode
d)Areas do not affect corrosion rates
36. If a particular zinc anode had an actual capacity of 275 amp-hrs/yr, its efficiency
would be which of the following?
a)47%.
b)65%.
c)74%.
d)105%.
37. A combination of coatings and cathodic protection is required and beneficial for
the following reasons
I. defect free coatings cannot be produced or maintained during service.
II. cathodic protection of a bare substrate requires more current.
III.coatings may be damaged by CP.
IV.coating service life in increased.
a)I, II and IV only
b)I, II, and III only
c)I, III, and IV only
d)I, II, III, and IV
38. Cathodic disbondment is normally only associated with ______________.
a)impressed current CP systems.
b)galvanic CP systems.
c)intergranular corrosion.
d)intragranular corrosion.
39. Anodes used in the ICCP system are constructed of a single continuous
_________-coated tantalum or ________ wire rod woven through an insulating
glass-reinforced polyester holder.
a)niobium/platinum
b)platinum/niobium
c)platinum/zirconium
d)zirconium/platinum
40. The most commonly used reference electrode in marine environments is
the.________________
a)copper/copper sulfate (CCS) reference electrode.
b)silver/silver chloride (SSC) reference electrode.
c)zinc reference electrode.
d)calomel reference electrode.
41. SJ and LJ Ag/AgCl electrodes may have different potentials relative to the SHE.
Potentials of SJ Ag/AgCl electrodes are affected by the.____________
a)KCl solution adjacent to the active element.
b)orientation with electrolyte.
c)chloride concentration of electrolyte.
d)NaCl solution adjacent to the active element.
42. The shaft grounding assembly electrically connects the rotating propeller shaft to
the ______. The assembly allows for a _________
a)hull/reduction of CP currents.
b)hull/return path of CP currents.
c)hull/cancellation of CP currents.
d)power supply./reduction of CP currents.
43. The controller measures the potential of the hull versus the reference electrode and
signals the ______________ to adjust current output, to reduce the potential
difference between the _______ potential and the preset desired potential.
a)technician/hull
b)Power supply/reference
c)Shaft ground/hull
d)Power supply/hull
44. The CP current demand _____________
a)remains constant as ship speed increases.
b)decreases as ship speed increases.
c)increases as ship speed increases.
d)remains constant as ship speed decreases.
45. When a ship moves from saltwater to fresh water, CP current demand __________
a)decreases.
b)increases.
c)remains the same.
d)is unstable.
46. Cathodic protection occurs at the point where current______________________
a)leaves the metal from the anode.
b)enters the metal from the cathode.
c)enters the metal from the electrolyte.
d)leaves the metal from cathode.
47. Concerning the “minimum of 100 mV of cathodic polarization” criterion listed in
NACE RP0169 (latest revision), polarization can be measured by which of the
following?
I. Formation
II. Determining the IR drop in the metal path
III.Decay
IV.Determining the “on” potential
a)I only
b)III only
c)I and III
d)II and IV
48. Which of the following forms of corrosion is likely to occur when an old steel pipe
is welded to a new steel pipe and the assembly is placed in a common electrolyte?
a)Environmental cracking
b)Uniform attack
c)Galvanic attack
d)Intergranular attack
49. Increased movement of the submerged structure or the electrolyte adjacent to the
structure will result in___________________
a)an increase in polarization and a decrease in current.
b)a decrease in polarization and an increase in current.
c)an increase of hydrogen and a decrease in anodic sites.
d)a decrease of anodic sites and an increase of cathodic sites.
50. An increase in temperature on the structure will affect the polarization of the
_____________
a)anodic locations only.
b)cathodic locations only.
c)anodic and cathodic locations.
d)high resistivity areas.
51. Dezincification is an example of which of the following types of corrosion?
a)Selective leaching
b)Velocity phenomena
c)Galvanic attack
d)Intergranular attack
52. If current increases in a cathodic protection system,
polarization_________________
a)passivates.
b)decreases.
c)increases.
d)remains dormant.
53. Hydrogen embrittlement is an example of which of the following forms of
corrosion?
a)Intergranular attack
b)Selective leaching
c)Environmental cracking
d)Crevice corrosion
54. When dealing with cathodic polarization an increase in dissolved oxygen will
result in_____________________
a)an increase in anaerobic bacteria.
b)an increased risk of hydrogen damage.
c)an increase in the passive film.
d)a decrease in polarization.
55. Polarization occurs___________________________
a)in the metal paths between the anode and the cathode.
b)in the bulk electrolyte between the anode and the cathode.
c)at the surface of the anodic and cathodic sites.
d)across the porous plug of a copper-copper sulfate reference electrode.
56. In a metal ion concentration cell, the surface in contact with the lower
concentration of metal ions acts as the________________
a)polarized portion.
b)reduction site.
c)cathode.
d)anode.
57. In an oxygen concentration cell the area of the submerged structure which has little
or no oxygen is the________________________
a)cathode.
b)anode.
c)electrolyte.
d)noble site.
58. When the voltage difference between the anode and the cathode increases, the
corrosion rate will_______________ (Corrosion Theory)
a)decrease.
b)increase.
c)polarize.
d)passivate.
59. Which of the following sacrificial anodes is the most active? (Corrosion Theory,
EMF and Galvanic Series)
a)Zinc
b)Aluminum
c)Aluminum-zinc-indium
d)Magnesium
60. When electrically interconnecting two different metals in a common electrolyte,
the more active metal will tend to become________________
a)passive.
b)cathodic.
c)anodic.
d)protected.
61. An DC ohmmeter is NOT suitable for testing__________________
a)circuit continuity.
b)resistor panels.
c)casing-to-pipe resistance.
d)huntington trap resistance
62. Direct current flow is considered to be_______________
a)bi-directional.
b)multi-directional.
c)uni-directional.
d)non-directional.
Given: E=12 volts, R1 = 1 ohm, and R2 = 2 ohms
for the following circuit, answer questions 63 and 64.
63. Current I2 is____________
a)4.0 A.
b)6.0 A.
c)12.0 A.
d)24.0 A.
64. Current from battery IT is___________________
a) 4 A.
b) 8 A.
c)18 A.
d)36 A.
65. Resistivity is usually defined as the resistance between two parallel faces of a cube
each measuring________________
a)1 foot.
b)1 inch.
c)1 centimeter.
d)1 millimeter.
Given: E1=40 volts, E2 = 40 volts R1 = 6 ohms, R2 = 6 ohms, R3 = 6 ohms and R4 = 22 ohms for
the following circuit, answer question 66.
66. IWhat is the current measured across R2?
a)3.33 amps
b)6.87 amps
c)13.33 amps
d)40.00 amps
67. Which of the following forms of corrosion can be the result of excessive levels of
cathodic protection?
a)Selective leaching
b)Hydrogen embrittlement
c)Galvanic corrosion
d)Concentration cell corrosion
68. Reduction is the________________
a)loss of cations.
b)gaining of electrons.
c)loss of electrons.
d)loss of conductivity.
I1 R1 I2 R2 I3 R3
IT
IT
E1
E2
I4 R4
69. According to Faraday’s Law the rate of corrosion is directly proportional
to_____________
a)voltage drop.
b)current.
c)resistance.
d)pH.
70. Criteria for cathodic protection of submerged steel according to the latest revision
of NACE RP0169 include which of the following?
I. A negative (cathodic) potential of at least 850 millivolts relative to a saturated
copper/copper sulfate reference electrode
II. with cathodic protection applied (considering IR drop)
III.A negative polarized potential of at least 850 millivolts relative to a saturated
copper/copper sulfate reference electrode
IV.A minimum of 100 millivolts of cathodic polarization between the structure
surface and a stable reference electrode contacting the electrolyte.
a)III only
b)I and II only
c)II and III only
d)I, II and III
71. Voltage drop errors in the measuring circuit are minimized under which of the
following conditions?
I. Good metal/metal contacts are made.
II. A high-input impedance meter is used.
III.Soil resistivity is high.
IV.Cathodic protection current density is low.
a)IV only
b)II and III only
c)I,II, and IV only
d)I,II, III and IV
72. The IR drop across the electrolyte can be reduced to near zero
by________________
a)placing the reference electrode 3 feet (1 meter) from the structure being
monitored.
b)using the Pearson survey method.
c)interrupting the current.
d)using the 4-pin Wenner method.
73. Which of the following is an example of detrimental effects due to excessive
cathodic protection on a structure?
a)Atomic hydrogen at the anode will diffuse into the metal
b)Buildup of hydrogen gas can cause coating adhesion
c)Coating blistering may occur
d)pH values of 1 to 3 will occur
74. Which of the following are associated with anaerobic bacteria corrosion?
I. Abundance of oxygen
II. Consumption of hydrogen at the structure surface
III.Absence of oxygen
IV.Presence of chlorine
a)I only
b)I & II only
c)I and IV only
d)II and III only
75. In addition to steel, NACE RP0169 (latest revision) also includes cathodic
protection criteria for which of the following?
I. Aluminum
II. Cast iron
III.Dissimilar metal piping
IV.Copper
a)I and IV only
b)II and III only
c)I, II, and IV only
d)I, II, III, and IV
76. Which of the following is NOT caused by the excessive application of cathodic
protection current?
a)Coating disbondment
b)Corrosion of aluminum
c)Hydrogen embrittlement
d)Increased bacteria activity
77. Concerning the “negative polarized potential of at least 850 mV” criterion listed
in NACE RP0169 (latest revision), structure-to-electrolyte potentials must be
recorded using a_________________
a)zinc reference electrode.
b)silver/silver chloride reference electrode.
c)calomel reference electrode.
d)copper/copper sulfate reference electrode.
78. A polarized potential is defined as the potential across the structure/electrolyte
interface that is the _____________________
a)difference between the corrosion potential and the cathodic polarization.
b)sum of the corrosion potential and the cathodic polarization.
c)sum of the corrosion potential and the native potential.
d)difference between the corrosion potential and the native potential.
79. What must be considered for valid interpretation of the NACE RP0169 ” -0.85V
ON” criteria?
a)Voltage drops other than those across the structure-to-electrolyte boundary.
b)All voltage drops.
c)Voltage drops in the measuring circuit.
d)Voltage drops across the structure-to-electrolyte boundary only.
80. A structure may be shielded and prevented from receiving adequate cathodic
protection when_______________
a)baffles in vessels are not installed.
b)there is proper shaft grounding.
c)the ship is in close proximity to pier.
d)structural members are not installed in tanks.
81. Which of the following is decreased as a result of increasing temperature?
a)Corrosion rate
b)Cathodic protection current requirement
c)Activation polarization
d)Diffusion rate of reducible species to the cathodic sites
82. Which of the following metals or alloys is most susceptible to overprotection?
a)Copper
b)Cast iron
c)Low-strength carbon steel
d)Aluminum
83. Amphoteric materials can be damaged by high alkalinity conditions created
by_____________
a)low levels of cathodic protection.
b)high levels of cathodic protection.
c)highly acidic environments.
d)near neutral acidic environments.
84. Which of the following are environments in which anodes and cathodes on steel
can coexist?
I. Freshwater (less than 500 ppm sodium chloride [NaCl])
II. Brackish water (more than 500 ppm sodium chloride [NaCl]
III.Concrete
a)III only
b)I and II only
c)II and III only
d)I,II and, III
85. Stress corrosion cracking can occur when______________________
a)atomic hydrogen diffuses into the metal.
b)carbonates and bicarbonates have not formed at the steel surface.
c) metal is under an applied tensile load in the presence of a corrosive
environment.
d)the potential range is (–300 to –500 mV CSE) at a pH between 8 and 10.5.
86. A rectifying stack for a single-phase bridge rectifier circuit has how many legs?
a)2
b)4
c)6
d)8
87. The effectiveness of cathodic protection can be determined by which of the
following techniques?
a)Diver visual inspection
b)ROV visual inspection
c)Review of cathodic protection logs
d)Ultrasonic hull thickness survey
88. Which of the following is a disadvantage of using cathodic protection coupons?
a)IR-drop free potentials can be obtained without interrupting multiple power
sources
b)Depolarization test can be conducted without de-energizing the CP system
c)Structure-to-reference potentials can be measured with direct-coupled
galvanic anodes
d)A discrepancy may exist between the polarized potential of the coupon and
that of the structure
89. As a structure remains protected for an extended period in full strength sea water
the current demand of the structure will _____________________________
a)decreases due to increased temperature.
b)decreases due to calcareous deposit growth.
c)decreases due to loss of paint.
d)decreases due to increased velocity.
90. Stainless steel grades which are relatively immune to stress corrosion cracking
include which of the following?
a)Ausentic and ferretic
b)Ausentic and martensitic
c)Ferretic and martensitic
d)Martensitic and precipitation hardened
91. A vessel with an aluminum hull is outfitted win a NAB propeller and Cu/Ni
through hull fittings. What is the best choice for a Cathodic Protection System?
I. ICCP
II. Zn System
III.Mg System
IV.Al System
a)I or III
b)I or II
c)I or IV
d)I only
92. When a ship moves from sea water to fresh water current output and driving
voltage____________
a)decreases.
b)increases.
c)remains the same.
d)is unstable.
93. Upon inspection of a cathodically protected ship, luminous white products are
noted on the ship’s propellers. The luminous white products are
likely_____________
a)NAB corrosion products.
b)marine growth.
c)calcareous deposits.
d)aluminum oxide.
94. Aluminum anodes should not be used for cathodic protection in or
of______________
a)sea water.
b)fresh water.
c)brackish water
d)low carbon steel.
95. On impressed current cathodically protected surfaces the following are true facts.
I. Chlorine gas is generated at the anode.
II. Hydrogen gas is generated at the anode.
III.Hydrogen gas is generated at the cathode.
IV.Oxygen gas is reduced at the anode.
a)I only
b)II and IV
c)I and III
d)I and IV
96. The lack of what element or compound generates the driving force for localized
crevice corrosion attack?
a)H
b)O2
c)N
d)Cl
97. As a painted structure remains protected for an extended period in full strength sea
water the current demand of the structure will___________________.
a)decrease due to increased temperature.
b)decrease due to calcareous deposit growth.
c)decrease due to loss of paint.
d)decrease due to increased velocity.
98. Which reference electrode is most commonly used to calibrate a silver/silver
chloride reference electrode for seawater use?
a)Zinc
b)Copper-copper sulfate
c)Silver/silver chloride
d)Manganese dioxide
99. Which of the following levels of measured AC-to-ground voltages is considered
hazardous on metallic structures?
a)5 volts
b)10 volts
c)12 volts
d)15 volts
100. Sources of dynamic stray currents include which of the following?
I. Cathodic protection systems
II. HVDC ground electrodes
III.Telluric currents
IV.DC electric railway systems
a)II only
b)IV only
c)I and II
d)III and IV
