Arizona C-11 Electrical Contractor Certification
Practice Exam Newest (2026 Update) Actual
Practice Questions – Set 100 Most Common
Exam Questions And Answers In Details 100%
Verified Exam
1. A contractor is installing branch circuits in a residential dwelling. What is the
minimum ampacity required for a 20-ampere branch circuit supplying
continuous load?
A. 16 amps
B. 20 amps
C. 25 amps
D. 30 amps
✔ Correct Answer: C. 25 amps (25 amps)
Explanation: Continuous loads must be calculated at 125% of the load. 20
× 1.25 = 25 amps.
2. Which NEC article covers grounding and bonding requirements?
A. Article 110
B. Article 250
C. Article 300
D. Article 400
✔ Correct Answer: B. Article 250 (Article 250)
Explanation: NEC Article 250 specifically governs grounding and bonding.
3. What is the maximum voltage for low-voltage lighting systems as defined by
NEC?
A. 30 volts
B. 50 volts
, C. 100 volts
D. 120 volts
✔ Correct Answer: B. 50 volts (50 volts)
Explanation: NEC defines low voltage as 50 volts or less.
4. A conductor is rated THHN. What does the "H" indicate?
A. Heat resistant
B. High voltage
C. Heavy duty
D. Hazard rated
✔ Correct Answer: A. Heat resistant (Heat resistant)
Explanation: THHN insulation includes heat-resistant properties.
5. What is the purpose of a ground-fault circuit interrupter (GFCI)?
A. Prevent overload
B. Detect arc faults
C. Protect against shock
D. Increase voltage
✔ Correct Answer: C. Protect against shock (Protect against shock)
Explanation: GFCIs protect people from electrical shock by detecting
imbalance.
6. In a commercial installation, what is the minimum working clearance in
front of a 480V panel?
A. 2 feet
B. 3 feet
C. 4 feet
D. 5 feet
✔ Correct Answer: B. 3 feet (3 feet)
Explanation: NEC requires minimum 3 feet clearance depending on
conditions.
7. What type of conduit is permitted for direct burial?
A. EMT
, B. RMC
C. PVC
D. FMC
✔ Correct Answer: C. PVC (PVC)
Explanation: PVC conduit is approved for direct burial installations.
8. Which device protects against arc faults?
A. GFCI
B. AFCI
C. Breaker
D. Fuse
✔ Correct Answer: B. AFCI (AFCI)
Explanation: AFCIs detect arc faults and prevent fires.
9. What color is typically used for grounded (neutral) conductors?
A. Black
B. Red
C. White
D. Green
✔ Correct Answer: C. White (White)
Explanation: White or gray indicates grounded conductor.
10.What is the maximum number of conductors allowed in a 4-inch square box
without derating?
A. 8
B. 10
C. 12
D. Depends on conductor size
✔ Correct Answer: D. Depends on conductor size (Depends on conductor
size)
Explanation: Box fill is calculated based on conductor gauge.
11.What NEC article governs overcurrent protection?
A. 210
Practice Exam Newest (2026 Update) Actual
Practice Questions – Set 100 Most Common
Exam Questions And Answers In Details 100%
Verified Exam
1. A contractor is installing branch circuits in a residential dwelling. What is the
minimum ampacity required for a 20-ampere branch circuit supplying
continuous load?
A. 16 amps
B. 20 amps
C. 25 amps
D. 30 amps
✔ Correct Answer: C. 25 amps (25 amps)
Explanation: Continuous loads must be calculated at 125% of the load. 20
× 1.25 = 25 amps.
2. Which NEC article covers grounding and bonding requirements?
A. Article 110
B. Article 250
C. Article 300
D. Article 400
✔ Correct Answer: B. Article 250 (Article 250)
Explanation: NEC Article 250 specifically governs grounding and bonding.
3. What is the maximum voltage for low-voltage lighting systems as defined by
NEC?
A. 30 volts
B. 50 volts
, C. 100 volts
D. 120 volts
✔ Correct Answer: B. 50 volts (50 volts)
Explanation: NEC defines low voltage as 50 volts or less.
4. A conductor is rated THHN. What does the "H" indicate?
A. Heat resistant
B. High voltage
C. Heavy duty
D. Hazard rated
✔ Correct Answer: A. Heat resistant (Heat resistant)
Explanation: THHN insulation includes heat-resistant properties.
5. What is the purpose of a ground-fault circuit interrupter (GFCI)?
A. Prevent overload
B. Detect arc faults
C. Protect against shock
D. Increase voltage
✔ Correct Answer: C. Protect against shock (Protect against shock)
Explanation: GFCIs protect people from electrical shock by detecting
imbalance.
6. In a commercial installation, what is the minimum working clearance in
front of a 480V panel?
A. 2 feet
B. 3 feet
C. 4 feet
D. 5 feet
✔ Correct Answer: B. 3 feet (3 feet)
Explanation: NEC requires minimum 3 feet clearance depending on
conditions.
7. What type of conduit is permitted for direct burial?
A. EMT
, B. RMC
C. PVC
D. FMC
✔ Correct Answer: C. PVC (PVC)
Explanation: PVC conduit is approved for direct burial installations.
8. Which device protects against arc faults?
A. GFCI
B. AFCI
C. Breaker
D. Fuse
✔ Correct Answer: B. AFCI (AFCI)
Explanation: AFCIs detect arc faults and prevent fires.
9. What color is typically used for grounded (neutral) conductors?
A. Black
B. Red
C. White
D. Green
✔ Correct Answer: C. White (White)
Explanation: White or gray indicates grounded conductor.
10.What is the maximum number of conductors allowed in a 4-inch square box
without derating?
A. 8
B. 10
C. 12
D. Depends on conductor size
✔ Correct Answer: D. Depends on conductor size (Depends on conductor
size)
Explanation: Box fill is calculated based on conductor gauge.
11.What NEC article governs overcurrent protection?
A. 210
