Certification Practice Exam Newest (2026
Update) Actual Practice Questions – Set 100
Most Common Exam Questions And Answers
In Details 100% Verified Exam
1. A branch circuit supplies continuous lighting load of 16A. What is the
minimum circuit rating required?
A. 15A
B. 16A
C. 20A
D. 25A
✔ Correct Answer: C (20A)
Explanation: Continuous loads must be calculated at 125%, so 16A × 1.25 =
20A.
2. What is the minimum burial depth for rigid metal conduit under a
residential driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
✔ Correct Answer: B (12 inches)
Explanation: NEC requires 12 inches for RMC under driveways.
3. A 240V circuit draws 24A. What is the minimum conductor size (copper,
75°C)?
A. 14 AWG
B. 12 AWG
C. 10 AWG
, D. 8 AWG
✔ Correct Answer: C (10 AWG)
Explanation: 10 AWG copper is rated for 30A, sufficient for 24A load.
4. What device protects against ground-fault currents in wet locations?
A. AFCI
B. GFCI
C. Fuse
D. Relay
✔ Correct Answer: B (GFCI)
Explanation: Ground-Fault Circuit Interrupters detect imbalance and
protect people.
5. What is the maximum number of conductors in a 4-inch square box with
1.5-inch depth using 12 AWG?
A. 6
B. 8
C. 9
D. 10
✔ Correct Answer: B (8)
Explanation: Box fill calculation per NEC assigns 2.25 in³ per 12 AWG
conductor.
6. What is the standard voltage for a single-phase residential service in the
U.S.?
A. 120V
B. 208V
C. 120/240V
D. 277V
✔ Correct Answer: C (120/240V)
Explanation: Typical residential service is split-phase 120/240V.
7. What is required for all 125–250V receptacles in bathrooms?
A. AFCI
, B. GFCI
C. Isolated ground
D. Surge protector
✔ Correct Answer: B (GFCI)
Explanation: NEC mandates GFCI protection in bathrooms.
8. What is the minimum working clearance in front of electrical panels?
A. 24 inches
B. 30 inches
C. 36 inches
D. 48 inches
✔ Correct Answer: C (36 inches)
Explanation: NEC requires 36-inch depth clearance.
9. Which conductor is typically used for grounding?
A. Black
B. Red
C. Green
D. White
✔ Correct Answer: C (Green)
Explanation: Green or bare conductors are used for grounding.
10.What is the maximum overcurrent protection for 14 AWG copper?
A. 10A
B. 15A
C. 20A
D. 25A
✔ Correct Answer: B (15A)
Explanation: NEC limits 14 AWG to 15A.
11.A motor draws 18A full-load current. What size breaker is typically used?
A. 20A
B. 25A
C. 30A