Corrosion Technician Practice Exam
1. Corrosion is best defined as:
A. Rust formation only
B. Deterioration of a material due to reaction with its
environment
C. Cracking caused by high stress
D. Loss of coating adhesion
Answer: B
Explanation: Corrosion is the electrochemical deterioration of
metal in the environment.
2. The four basic elements required for corrosion are:
A. Metal, air, sunlight, coating
B. Anode, cathode, electrolyte, metallic path
C. Water, salt, temperature, pressure
D. Oxygen, nitrogen, hydrogen, CO₂
Answer: B
Explanation: These four components create an
electrochemical cell.
3. The anode in a corrosion cell is where:
A. Reduction occurs
B. Metal loss occurs
,C. Oxygen is produced
D. The cathodic reaction happens
Answer: B
Explanation: Metal is oxidized and released as ions at the
anode.
4. Which metal is MOST active (least noble)?
A. Copper
B. Zinc
C. Stainless steel
D. Platinum
Answer: B
Explanation: Zinc is highly active and often used as a
sacrificial anode.
5. Which environment is MOST corrosive to steel?
A. Dry air
B. Fresh distilled water
C. Moist, oxygen-containing soil
D. Dry nitrogen gas
Answer: C
Explanation: Moisture + oxygen = active corrosion cell.
6. Cathodic protection works by making the protected
structure:
,A. The anode
B. The cathode
C. Electrically isolated
D. A conductor
Answer: B
Explanation: CP stops corrosion by forcing steel to act as the
cathode.
7. Which is an example of a sacrificial anode?
A. Platinum
B. Magnesium
C. Stainless steel
D. Copper
Answer: B
Explanation: Magnesium is highly active and used as a
sacrificial anode, especially in soil.
8. The standard reference electrode used in soil is:
A. Ag/AgCl (seawater)
B. Cu/CuSO₄
C. Zinc
D. Lead-silver
Answer: B
Explanation: Cu/CuSO₄ is the standard for soil potential
measurements.
, 9. A minimum protection criterion for steel in soil is:
A. –500 mV
B. –850 mV
C. +100 mV
D. –200 mV
Answer: B
Explanation: –850 mV vs Cu/CuSO₄ is widely used as CP
criterion.
10. IR drop affects which potential reading?
A. ON reading
B. OFF reading
C. Both ON and OFF
D. None
Answer: A
Explanation: ON potentials include voltage losses through the
soil (IR drop).
11. Instant-OFF potentials are used because:
A. They include IR drop
B. They eliminate most of the IR drop
C. They are easier to measure
D. They use AC current
Answer: B
Explanation: OFF potentials represent true polarization level.
1. Corrosion is best defined as:
A. Rust formation only
B. Deterioration of a material due to reaction with its
environment
C. Cracking caused by high stress
D. Loss of coating adhesion
Answer: B
Explanation: Corrosion is the electrochemical deterioration of
metal in the environment.
2. The four basic elements required for corrosion are:
A. Metal, air, sunlight, coating
B. Anode, cathode, electrolyte, metallic path
C. Water, salt, temperature, pressure
D. Oxygen, nitrogen, hydrogen, CO₂
Answer: B
Explanation: These four components create an
electrochemical cell.
3. The anode in a corrosion cell is where:
A. Reduction occurs
B. Metal loss occurs
,C. Oxygen is produced
D. The cathodic reaction happens
Answer: B
Explanation: Metal is oxidized and released as ions at the
anode.
4. Which metal is MOST active (least noble)?
A. Copper
B. Zinc
C. Stainless steel
D. Platinum
Answer: B
Explanation: Zinc is highly active and often used as a
sacrificial anode.
5. Which environment is MOST corrosive to steel?
A. Dry air
B. Fresh distilled water
C. Moist, oxygen-containing soil
D. Dry nitrogen gas
Answer: C
Explanation: Moisture + oxygen = active corrosion cell.
6. Cathodic protection works by making the protected
structure:
,A. The anode
B. The cathode
C. Electrically isolated
D. A conductor
Answer: B
Explanation: CP stops corrosion by forcing steel to act as the
cathode.
7. Which is an example of a sacrificial anode?
A. Platinum
B. Magnesium
C. Stainless steel
D. Copper
Answer: B
Explanation: Magnesium is highly active and used as a
sacrificial anode, especially in soil.
8. The standard reference electrode used in soil is:
A. Ag/AgCl (seawater)
B. Cu/CuSO₄
C. Zinc
D. Lead-silver
Answer: B
Explanation: Cu/CuSO₄ is the standard for soil potential
measurements.
, 9. A minimum protection criterion for steel in soil is:
A. –500 mV
B. –850 mV
C. +100 mV
D. –200 mV
Answer: B
Explanation: –850 mV vs Cu/CuSO₄ is widely used as CP
criterion.
10. IR drop affects which potential reading?
A. ON reading
B. OFF reading
C. Both ON and OFF
D. None
Answer: A
Explanation: ON potentials include voltage losses through the
soil (IR drop).
11. Instant-OFF potentials are used because:
A. They include IR drop
B. They eliminate most of the IR drop
C. They are easier to measure
D. They use AC current
Answer: B
Explanation: OFF potentials represent true polarization level.
