AMPP Cathodic Protection Tester (CP1) Practice Questions — 10 Free (2026)

A groundbed of 2.5 ohms is in series with cable and structure resistances totalling 1.5 ohms. A 16.0 V rectifier drives the circuit. What current flows?

• A. 1.60 A
• B. 3.20 A
• C. 4.00 A ✓
• D. 6.40 A
• E. 10.67 A

Series resistances are added first and the driving voltage is then divided by that total. Using only one of the resistances gives the larger values offered. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 1.3

Four anode leads carry 1.2, 0.9, 1.4 and 1.0 A. What is the total groundbed output?

• A. 0.90 A
• B. 1.13 A
• C. 4.50 A ✓
• D. 5.40 A
• E. 18.00 A

Parallel branch currents add to give the total leaving the groundbed. Quoting the smallest branch, the average, or the product is incorrect. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 3.4

Why does anode output usually fall over the life of a galvanic anode installation?

• A. The anode loses mass and surface area while corrosion products build up, raising its resistance to earth and reducing the current it can deliver ✓
• B. The driving voltage of the anode material falls steadily to zero within a few months of it being installed in the ground in every case without exception
• C. The structure becomes more corrosive over time and rejects the current
• D. The soil resistivity around the anode falls as the anode is consumed
• E. The metallic connection between anode and structure improves with age

A shrinking anode with accumulating products presents a higher resistance to earth, so with a fixed driving voltage the current falls, which is why output is monitored. A collapsing driving voltage, a rejecting structure, falling resistivity and an improving connection are wrong. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 1.5

Why should isolation be verified after maintenance work at a station?

• A. Because maintenance work always damages the coating on the pipeline near the isolation joint at that location
• B. Because temporary earths, scaffolding, new pipework and instrument connections can bridge a joint and be left in place ✓
• C. Because maintenance work changes the resistivity of the soil around the station and so alters the isolation performance
• D. Because isolation joints must be replaced after every maintenance shutdown
• E. Because maintenance work reverses the polarity of the rectifier output

Bonds and connections installed for safety or convenience during work are a common cause of a joint being shorted afterwards, so verification closes out the work. Inevitable coating damage, soil resistivity changes, mandatory replacement and polarity reversal are not the reason. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 3.8

What is the practical advantage of a coupon over interrupting the whole system?

• A. A coupon removes the need to record any potential readings at all
• B. Only the coupon has to be disconnected ✓
• C. A coupon lowers the resistivity of the soil at the monitoring location in every case without exception
• D. A coupon raises the driving voltage available from the rectifier there
• E. A coupon removes the need to calibrate the measuring instruments used

Leaving the system running while still obtaining an IR free value is the practical benefit. Records, resistivity, driving voltage and calibration are unaffected. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 3.3

Why is a reference electrode checked against a second electrode before and after a survey?

• A. Because comparison recharges the electrode solution and restores its potential to the correct value for the next survey
• B. Because the comparison establishes the resistivity of the soil at the point where the two electrodes are placed together in every case without exception
• C. Because contamination or a dried plug can shift the electrode potential, and comparison detects a shift that would invalidate the readings ✓
• D. Because two electrodes are required by every survey procedure
• E. Because the comparison sets the polarity convention for the survey

A drifting electrode biases every reading taken with it, so comparing against a clean reference before and after the work shows whether the data can be trusted. Recharging, resistivity measurement, a two-electrode requirement and polarity setting are not the purpose. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 2.2

What information does an alignment sheet typically carry that assists corrosion work?

• A. Pipe size and grade, coating type, depth of cover, crossings, valves, casings and the position of test facilities ✓
• B. Only the geographic coordinates of the pipeline centreline with no other detail of the installation being surveyed
• C. Only the operating pressure history of the pipeline over the previous twelve months of service in the system
• D. Only the names of the landowners along the right of way of the pipeline
• E. Only the results of the most recent potential survey of the section

Alignment sheets combine route geometry with the physical detail that explains survey behaviour, such as a casing that shields or a coating change that alters current demand. Coordinates alone, pressure history, landowner details or previous results alone would not support the interpretation. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 4.2

Why is a site-specific hazard assessment carried out before cathodic protection field work?

• A. Because the assessment determines the criterion that will be applied to the readings taken at that site during the visit
• B. Because the assessment establishes the calibration status of the instruments that are to be used during the work
• C. Because hazards differ from site to site ✓
• D. Because the assessment determines the reference electrode type to be used
• E. Because the assessment determines how many readings must be taken

Traffic, excavations, live plant, confined spaces and electrical hazards vary by location, so the controls have to be chosen for the site rather than applied generically. Criteria, calibration, electrode selection and reading counts are not outputs of a hazard assessment. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 5.1

How does current move through an electrolyte, as distinct from through a metal?

• A. Charged ions migrate through the electrolyte, whereas electrons carry the charge inside a metallic conductor ✓
• B. Electrons travel through the electrolyte in the same way that they travel through a copper conductor connected to it
• C. Current passes through an electrolyte only when the liquid is boiling
• D. Current cannot flow through an electrolyte at all
• E. Current passes as heat rather than as charge in any wet environment

Conduction in soil or water is ionic, with positive and negative ions drifting in opposite directions, while metals conduct by electron movement, and the corrosion cell needs both paths. Electron conduction in solution, boiling requirements, no conduction and heat transport all misdescribe the mechanism. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 1.4

A stray current of 2 A is discharging from a pipeline. Using 9 kg per ampere-year for steel, how much steel is lost in six months?

• A. 1.5 kg
• B. 4.5 kg
• C. 9.0 kg ✓
• D. 18.0 kg
• E. 36.0 kg

Two amperes for half a year is one ampere-year of charge, which corresponds to about 9 kilograms of steel, an alarming loss concentrated at the discharge point. Ignoring the half-year factor, applying it twice or misreading the rate produce the other answers. AMPP/NACE CP 1 Cathodic Protection Tester course manual and exam preparation guide, 1.5