AMPP Cathodic Protection Technician (CP2) Practice Questions — 10 Free (2026)

A coating defect of 5 square centimetres discharges 1.0 mA. What is the current density at the defect in milliamperes per square metre?

• A. 20
• B. 200
• C. 2000 ✓
• D. 5000
• E. 20000

Five square centimetres is 0.0005 square metres, and 1.0 milliampere divided by that area gives 2000 milliamperes per square metre, an extremely high density that removes metal quickly. Errors in the area conversion produce the other options. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 1.2

What effect does a bare foreign structure connected to a protected line have?

• A. It reduces the current demand of the system because the two structures share the current already being supplied in every case without exception
• B. It adds a large bare surface to the protected system, so current demand rises sharply and the intended structure may lose protection ✓
• C. It has no effect provided the two structures are made from the same grade of steel at the point where they meet
• D. It raises the resistivity of the soil between the two structures
• E. It reverses the polarity of the rectifier serving that section

An unintended metallic contact makes the foreign structure part of the system, and its bare area soaks up current that the pipeline needs. Reduced demand, no effect, resistivity change and polarity reversal are all incorrect. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 2.1

Why is a deep bed often chosen in a congested urban corridor?

• A. Because a deep bed requires no electrical supply and can be installed where no power is available in every case without exception
• B. Because a deep bed consumes no anode material and so never requires replacement in service
• C. Because discharging from depth weakens the surface gradients that would otherwise interfere with nearby services ✓
• D. Because a deep bed always costs less to install than a shallow bed does
• E. Because a deep bed removes the need for any interference testing at commissioning

Moving the discharge away in depth flattens the potential gradients at the surface where other buried services lie, and it also gives a more even current spread. No power requirement, no consumption, lower cost and removing the testing obligation are all incorrect. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 7.2

Why is a rectifier with a blown fuse still worth recording in detail?

• A. Because the record determines the pipeline wall thickness
• B. Because the record determines the pipeline coating colour
• C. Because the record determines the resistivity of the local soil
• D. Because the record determines the calibration of the panel meters
• E. Because the structure has been unprotected since it failed ✓

An outage leaves the structure exposed and its length is part of the integrity picture. Wall thickness, colour, resistivity and calibration are unrelated. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 3.2

Why are readings taken in both directions or repeated over some sections?

• A. Because standards require every close interval survey to be walked twice along its full length in every case without exception
• B. Because repeatability confirms that a feature is real rather than an artefact of contact or operator technique ✓
• C. Because walking in the opposite direction reverses the polarity of the readings obtained
• D. Because a second pass is needed to calibrate the instrument being used
• E. Because a second pass measures the soil resistivity along the section

Confirming that an anomaly reappears distinguishes a genuine defect from a momentary poor contact. A universal requirement, polarity reversal, calibration and resistivity are not the reason. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 6.1

Why are separate test leads brought out from both the casing and the carrier pipe?

• A. Because separate leads determine the wall thickness of the carrier
• B. Because separate leads determine the coating colour of the carrier
• C. Because separate leads determine the internal pressure of the carrier in every case without exception
• D. Because the two potentials have to be measured independently before a short can be identified ✓
• E. Because separate leads determine the calibration of the survey meter

Without separate access the two structures cannot be compared and a short cannot be detected. Wall thickness, colour, pressure and calibration are unrelated. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 4.1

A remote site needs 0.5 A at 12 V continuously. What average power must the source supply?

• A. 0.5 W
• B. 2.4 W
• C. 6.0 W ✓
• D. 12.0 W
• E. 24.0 W

Multiplying 12 volts by 0.5 amperes gives 6.0 watts, which with allowances for losses and dark periods sizes the panel and battery. Dividing the values or misreading them produces the other answers. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 8.2

Why can a pipeline running parallel to overhead power lines carry a hazardous alternating voltage?

• A. Because the external coating conducts alternating current from the overhead conductors down to the steel in every case without exception
• B. Because the magnetic field of the conductors couples with the pipeline, which behaves like the secondary of a transformer ✓
• C. Because the cathodic protection rectifier converts part of its output back into alternating current
• D. Because the soil above the pipeline becomes charged during wet weather at that location
• E. Because the pipeline is earthed at both ends of the parallel section

Inductive coupling along a parallel run induces a voltage that can reach hazardous levels at above-ground appurtenances. Coating conduction, rectifier conversion, charged soil and earthing at the ends do not explain it. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 10.1

Why can an interfered structure read more negative at one place and less negative at another?

• A. Because current is picked up at one place and discharged at another ✓
• B. Because the wall thickness varies between the two locations
• C. Because the coating colour varies between the two locations
• D. Because the internal pressure varies between the two locations
• E. Because the instrument calibration varies between the locations in every case without exception

The pick up area is effectively cathodic while the discharge area is anodic, so the potentials move in opposite directions. Wall thickness, colour, pressure and calibration are unaffected. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 5.1

When is a clamp-on meter the right choice for a current measurement?

• A. Whenever the current to be measured is only a few milliamperes at the installation being surveyed that day
• B. Whenever a shunt is already fitted in the circuit and can be read with a voltmeter instead of a clamp
• C. Whenever the conductor to be measured is inside a bundle with several others at the location concerned
• D. Whenever the circuit has been opened for maintenance work at the site
• E. When a reading is needed on a single conductor without breaking the circuit ✓

Clamping suits single conductors carrying currents within the resolution of the instrument, and it avoids interrupting protection or a bond. Milliampere currents, an existing shunt, cable bundles and open circuits all point away from a clamp measurement. AMPP/NACE CP 2 Cathodic Protection Technician course manual, 3.2