Currents Latest Update - 80

NACE CP2 Student Manual Chapter 5 Stray Currents Latest Update - 80 Exam Questions with 100% Verified Correct Answers with Guaranteed A+ Verified by Professor

___ stray current can be both a safety hazard and a corrosion problem, ___ stray current causes significant corrosion of most metals.

A) DC , DC

B) AC, DC

C) DC, AC - CORRECT ANSWER: b

____ uses a long term way of recording stray current magnitude over time.

• Rectifier timer
• Stripe Anode
• Current interrupter

D) Data logger - CORRECT ANSWER: d

_____ currents are naturally occurring stray currents that are caused by disturbances in the Earth's magnetic field by sun spot activity.

• natural (telluric) currents
• static (steady state) currents

C) dynamic currents - CORRECT ANSWER: a

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_____ is where AC power is transmitted to ground the underground structure.

• electrostatic coupling
• Resistive coupling

C) Electromagnetic induction - CORRECT ANSWER: b

_____ is where the structure acts as one side of a capacitor with respect to ground, only concern when the structure is _____.

• electrostatic coupling ,above grade
• Resistive coupling, below ground

C) Electromagnetic induction, below ground - CORRECT ANSWER: a

______ allows us to relate the corrosion lost to the amount of current discharged.

• Faraday's Law
• Ohm's Law

C) Kirchoff's Law - CORRECT ANSWER: a

_______ , where the structure acts as the single-turn secondary of an air-core transformer in which the overhead power line is the primary, this type of induction may occur when the structure is _____ .

• electrostatic coupling ,above grade
• Resistive coupling, below ground
• Electromagnetic induction, above or below ground 2 / 3

D) electromagnetic induction, below ground - CORRECT ANSWER: c

_______ are available that block the low-potential DC cathodic protection current from leaking across an insulating device while still providing instant protection from high- voltage spikes and _____.

• polarization cell, induced AC
• solid state devices, induced AC
• polarization cell, conducted AC

D) solid state devices, induced DC - CORRECT ANSWER: b

________ are currents through electrical paths other than the intended circuit.

• Eddy currents
• Stray currents
• Direct currents

D) Alternating currents - CORRECT ANSWER: b

• A DC discharge results in a loss of approximately ___lbs of steel in one year, while

one ampere of AC would consume less than__ lb.

A) 20, 1

B) 1, 20

C) 10, 5

D) 20, 5 - CORRECT ANSWER: a

A metallic bond may not perform properly in the case of a cathodically protected ______ that is causing interference on a _____ pipeline.

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