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ABYC CORROSION COMPREHENSIVE TEST
PAPER WITH COMPLETE SOLUTIONS
โโ T/F A galvanic isolator WILL block stray AC. Answer: False. A galvanic isolator WILL NOT block AC. It will only blocks stray DC that is moving through the green grounding conductor. โโ T/F An isolation transformer makes a galvanic isolator unnecessary. Answer: True. โโ An isolation transformer works through electromagnetic _________. Answer: Induction โโ A reverse polarity indicator is placed between which two wires? Why? Answer: White neutral and green grounding. If the black hot and white neutral are reversed, electricity will flow through the white neutral illuminating the indicator light and leaving through the green grounding conductor. โโ Bonding wires shall be at least #__ AWG Answer: #8 AWG
โโ Electrolytic corrosion is commonly known as: Answer: Stray-current corrosion โโ Stray-current corrosion is technically called: Answer: Electrolytic corrosion โโ Matter can exist as a Answer: Solid, liquid, or gas โโ Matter is made from Answer: Molecules โโ Molecules are made of Answer: Atoms โโ Atoms are made of Answer: protons, neutrons, electrons โโ The atom is electrically Answer: Neutral. That's because the particles that comprise an atom balance each other.
E.g. water, H2O โโ In ionic bonds, atoms form chemical bonds by _______ electrons. Answer: Giving up or gaining electrons. The atom giving an electron become a positive ion. The atom gaining an electron becomes a negative ion. Oppositely charged bodies are attracted to each other, bonding them together. E.g. Sodium Chloride, NaCl, table salt. โโ T/F Atoms in the valence shell are involved in the corrosion process? Answer: True โโ What is disassociation with regard to electrolyte? Answer: When an ionic substance (like sodium chloride, table salt) is immersed in water it disassociates, or separates, into positive and negative ions. โโ __________ are electrical conductors in which current is carried by ions rather than by free electrons. Answer: Electrolytes
โโ The three categories of corrosion are: Answer: Electrochemical, galvanic, and electrolytic โโ Single-metal corrosion is technically referred to as Answer: Electrochemical corrosion โโ Electrochemical corrosion is commonly known as Answer: Single-metal corrosion โโ Galvanic corrosion is sometimes referred to as Answer: Two-metal corrosion or bi-metallic corrosion โโ Corrosion is often improperly called Answer: Electrolysis. Electrolysis is what happens to the electrolyte not the metals involved. โโ ____________ is the destructive alteration of metal by reachtion with its environment. Answer: Corrosion
โโ Seawater is normally slightly Answer: Alkaline โโ Water that more basic is called Answer: Alkaline โโ When water is alkaline is it more Answer: Basic โโ If hydroxyl ions are allowed to concentrate in stagnant water the water can become strongly Answer: Alkaline (basic) โโ Strongly alkaline solutions can dissolve the lignin in wood. This is known as Answer: Alkali delignification โโ The speed of electrochemical corrosion is very Answer: Slow โโ What Aren the four things needed in galvanic corrosion? Answer: Anode, cathode, metallic path, electrolyte
โโ With galvanic corrosion, damage to wood is found near the Answer: Cathode โโ What does E-2 cover? Answer: Cathodic Protection โโ Cathode protection systems shall be capable of inducing and mainting a minimum negative shift of Answer: 200mV โโ The electric potential of underwater metals are measured in Answer: Millivolts (mV) โโ A reference potential reading in excess of - 1100 mV indicates what? Answer: Excessive cathodic protection. โโ What color and size conductor should be used for cathodic bonding? Answer: At least #8 AWG, green or green with s yellow stripe. โโ pH: A solution with a pH of 9.5 is: a. Basic
c. Cathode d. Anode Answer: B: Electrolysis โโ Matter is classified as a(n)? a. Element b. Compound c. Mixture d. All of these Answer: D: All of these โโ If an atom's outer shell, the valance ring, is full it's considered to be: a. Stable b. Unstable c. Negatively charged d. Positively charged Answer: A: Stable โโ Covalent bonding is a/an: a. Electrical bonding by sharing protons b. Electrical bonding by sharing electrons c. Chemical bonding by sharing electrons by same or similar elements
d. Chemical bonding by sharing protons by same or similar elements Answer: C: Chemical bonding by sharing electrons by the same or similar elements. โโ Electrochemical cells have electron flow from: a. Cathode to anode b. Anode to cathode c. Cathode to solution d. Anode to solution Answer: B: Anode to cathode โโ In an electrochemical cell, what is likely to lose metal or mass?? a. Anode b. Cathode c. Electrolyte d. Ions Answer: A: Anode โโ When using any of the Galvanic Series scales, what was used for reference? a. Zinc b. Aluminum c. Silver-SilverChloride
d. - 200 mV Answer: D. - 200 mV โโ You have a piece of aluminum that is caused by wet, absorbent material in contact with it. What type of corrosion would this be? a. Simple electrochemical b. Galvanic c. Electrolytic d. Poultice Answer: D: Poultice โโ Which of the following is not a likely source of stray current corrosion (electrolytic)? a. Faulty bilge pump float switch b. Faulty battery charger (ground fault) c. A lifeline failure due to corrosion d. A fault from a neighboring boat Answer: C. A lifeline failure โโ The white wire in a properly wired system will not be grounded at which of the following. a. Source of power b. Onboard generator
c. With the green wire to the engine block d. On board Inverter Answer: C. With the green wire to the engine block. โโ An atom becomes positive ion when it loses a valance electron a. True b. False c. Cannot be determined, need more information Answer: A. True โโ A molecule is two or more combined atoms of a. Different atoms b. The same atom c. Both of these are correct d. Neither of these are correct Answer: C. Both โโ ABYC E2, the potential range, for full protection, of a fiberglass boat is: a. - 500mV to - 900mV b. - 550mV to - 1100mV c. - 800mV to - 1100mV
Answer: B. Moving through metal โโ Simple electrochemical corrosion will occur: a. When a metal is freely corroding b. When metal is fully protected c. When metal has a positive potential difference d. When metal has a negative potential difference Answer: A. When a metal is freely corroding. โโ You are inspecting an old anodized aluminum mast on a sailboat. Anodizing is not: a. A process by which the metal is altered via an electric current or acid treatment b. A dye that can fill in the porous material for color c. A thick oxide layer that protects the mast d. A coating that is easily repairable, but expensive, on a mast Answer: D. A coating that is easily repairable. โโ You have a boat with a home port in a fresh water river that often travels for extended periods into the ocean. What type of sacrificial anode would you recommend? a. Aluminum b. Zinc
c. Magnesium d. Any of these will work, if sized properly Answer: A. Aluminum (E-2.7 Note 4) โโ A galvanic isolator allows AC current to pass through? a. True b. False c. Cannot be determined, need more information Answer: A. True โโ The extent of galvanic corrosion depends on: a. Voltage difference, how far apart on scale b. Relative area of the two metals c. The environment in which they are immersed d. All of these are true Answer: D. All of these โโ Atoms become more stable by sharing electrons. This is called ______ bonding. a. Polar b. Covalent c. Ionic
Answer: A. True โโ Bonding systems should utilize a _____ green wire to ensure all underwater fittings are a the same potential. The vessel does not have a lightning protection system. a. # b. # c. # d. # Answer: B. #8 AWG green โโ The reverse polarity light connects the white and green wires, which we don't want for corrosion & other issues, but must be present for safety reasons. Therefore it should have an impedance of at least ________ ohms. a. 25000 b. 12500 c. 0 d. Less than 5 Answer: A. 25000 ohms (E-11.6.2.2.4.2) โโ We have been referencing the galvanic series. Which of the following best describes it use? a. Inform us of the potential for interaction between metals
b. Predict corrosion rates of metals c. Inform us what type of fastener to select d. Predict what type of electrolyte is needed Answer: A. Inform us of the potential for interaction between metals. โโ What high performance stainless steel is used for propeller shafting? a. Nitronic 50 b. Aquamet 17 c. Aquamet 22 d. Monel Answer: C. Aquamet 22 (Collier Ch 8, pg 69) โโ The level of cathodic protection is determined by a. pH levels b. conductivity measurements c. Potential measurements d. continuity measurements Answer: C. Potential measurements โโ Which of the following is NOT a type of flow and velocity corrosion? a. Impingement corrosion
