NACE CP1 Quizzes, Practical with correct Answers

Ohm's Law relates the following... - ANSWER-volts, amps, resistance Resistance to current flow is lowest for a) low conductivity media b) small cross sectional area media c) short length of conductor d) high resistivity media - ANSWER-c In a series circuit a) voltage drops are always equal b) total resistance equals the sum of individual resistances c) current varies through resistors d) total current is equal to the sum of the current through each resistor - ANSWER-b According to Ohm's Law, an electrical circuit with a driving voltage of 12 Volts and a resistance of 10 Ohms produces a current of...(Amps) - ANSWER-1.2 A Kirchoff's Current Law - ANSWER-the total current entering a circuit branch must equal the current leaving the branch Kirchoff's Voltage Law - ANSWER-the sum of the voltage drops in a series circuit must equal the circuit's total voltage In a series electrical circuit a) current is different across each resistor b) Kirchoff's Voltage Law is obeyed c) voltage is the same across each resistor d) total resistance is the sum of the reciprocal of each resistance - ANSWER-b In a parallel electrical circuit a) total resistance is the sum of all of the resistors b) current is the same through each resistor c) voltage is different across each resistor d) voltage is the same across each resistor - ANSWER-d The driving voltage of an electrical circuit with a resistance of 1 Ohm and 100 mA is...(Volts) - ANSWER-0.1 V What is the total resistance in a series circuit consisting of three resistances: 1 Ohm, 2 Ohms, and 10 Ohms? - ANSWER-13 Ohms If a resistance of 0.17 Ohms was measured across a conductive material L = 1 m, D = 10 cm, what is its resistivity? - ANSWER-0.13 Ohm-cm Cations are _____ charged ions - ANSWER-positively Anions are ______ charged ions - ANSWER-negatively Which of the follow is true about an electrochemical cell? a) as polarization decreases, current will decrease b) as polarization increases, current will decrease c) as polarization increases, there is no change in current d) as polarization decreases, there is a decrease in driving voltage - ANSWER-b Why does corrosion rate decrease as polarization increases? - ANSWER-polarization lowers potential difference between anode and cathode, causing a reduction in corrosion current and corrosion rate The weight of any material deposited on the cathode or released from the anode is a) directly proportional to the current b) directly proportional to the total resistance c) inversely proportional to the current d) inversely proportional to the resistance - ANSWER-a Oxidation a) increases the negative charge of an atom or compound b) decreases the positive charge of an atom or compound c) is independent of reduction d) occurs when the electrons are lost from an atom or compound - ANSWER-d Electrochemical corrosion requires a) an anode and electronic path b) a cathode and electrolyte c) an anode, a cathode, and an electronic path d) an anode, a cathode, an electrolyte, and an electronic path - ANSWER-d In an anodic process a) positively charged ions leave the anode and enter the electrolyte b) electrons flow through the electronic path from cathode to anode c) negatively charged ions leave the anode and enter the electrolyte d) positively charged ions leave the cathode and enter the electrolyte - ANSWER-a An electrochemical reaction consists of a) an oxidation half reaction and electron movement in the metallic path b) a reduction half reaction and ionic movement in the electrolyte c) an oxidation half reaction, a reduction half reaction, and electron movement in the metallic path d) an oxidation half reaction, a reduction half reaction, ionic movement in the electrolyte, and electron movement in the metallic path - ANSWER-d Resistance is measured in... - ANSWER-Ohms In a corrosion cell, electrons flow in the direction of ______ through the _____ - ANSWER-anode to cathode, metallic (electronic) path Conventional current is in the direction of...(for electrolyte, for metallic path) - ANSWER-anode to cathode, cathode to anode The reduction reaction that occurs in an electrochemical reaction a) occurs at the anode b) occurs at the cathode c) occurs at the anode and involves the loss of electrons d) occurs at the cathode and involves the gain of electrons - ANSWER-d In the galvanic series, the more active metals a) are more cathodic metals than noble metals b) will corrode if connected to a less active metal c) will not corrode if connected to a less active metal d) are generally resistant to corrosion - ANSWER-b In a corrosion cell, which of the following is NOT required? a) oxygen b) cathode c) anode d) electrolyte - ANSWER-a The portion of the metal that is corroding is called the... - ANSWER-anode At the anode in an electrochemical corrosion cell a) electrons leave the anode and enter the electrolyte b) positively charged ions leave the anode and enter the electrolyte c) electrons leave the cathode and enter the electrolyte d) negatively charged ions leave the anode and enter the electrolyte - ANSWER-b Reactions in the electrochemical corrosion cell consist of... - ANSWER-oxidation, reduction, electron transfer through electronic path, ion transfer through the electrolyte In a galvanic series, compared to noble metals, the more active metals a) are resistant to corrosion b) are cathodic to the noble metals c) have a tendency to corrode more easily d) have a less negative potential - ANSWER-c Compared to an impressed current system, a galvanic anode system has the following advantage a) no external power is required b) current can easily be adjusted c) more suitable for high resistivity soil d) high current capacity - ANSWER-a Compared to magnesium anodes, zinc anodes tend to have a a) lower efficiency b) less negative open circuit potential c) higher current in higher soil resistivity d) lower life expectancy - ANSWER-b In an impressed current system, what rectifier terminal is connected to the anodes? - ANSWER-positive The quantity of polarization is determined by which structure to electrolyte potential? a) on b) off c) difference between on and off d) difference between off and native - ANSWER-d What is the difference between off and native structure to electrolyte potentials? - ANSWER-polarized potential The polarized potential criterion of -850 mVCSE for cathodic protection is for what metal? - ANSWER-steel The criterion of -850 mV is referenced to which electrode? - ANSWER-copper-copper sulfate A commonly used galvanic anode material for steel is... - ANSWER-magnesium Galvanic anodes are generally used where a) a large amount of current is required b) soil resistivity is high c) a small amount of current is required d) control of current is required - ANSWER-c The criterion for cathodic