Electrician License Exam
(Journeyman/State) Prep 2026 | NEC Code
Practice Questions, Answers & Detailed
Rationales | Electrical Theory & Exam
Success Guide
• This prep guide contains 200 NEC-based multiple choice questions with
highlighted correct answers and detailed EXPERT RATIONALE to reinforce
understanding of every concept tested on the Journeyman Electrician License Exam.
• Read each question carefully, attempt an answer before checking the correct
option, and study the EXPERT RATIONALE thoroughly — this method builds both
knowledge and exam-passing confidence.
1. What is the standard voltage for a single-phase residential service in the
United States?
A. 120/208V
B. 277/480V
C. 120/240V
D. 240/480V
E. 208/240V
C. 120/240V EXPERT RATIONALE: Standard single-phase residential service in the
US is 120/240V. This is a center-tapped transformer system providing 120V for general
receptacles and lighting, and 240V for larger appliances like dryers and ranges per NEC
Article 230.
2. According to the NEC, what is the minimum burial depth for rigid metal
conduit (RMC) under a residential driveway?
A. 6 inches
B. 12 inches
,C. 18 inches
D. 24 inches
E. 36 inches
B. 12 inches EXPERT RATIONALE: Per NEC Table 300.5, RMC installed under a
residential driveway requires a minimum burial depth of 12 inches. RMC's mechanical
strength allows for shallower burial compared to other wiring methods.
3. What is the maximum number of overcurrent devices permitted in a
lighting and appliance branch-circuit panelboard?
A. 30
B. 42
C. 48
D. 60
E. 84
B. 42 EXPERT RATIONALE: NEC 408.15 limits the number of overcurrent devices in a
lighting and appliance branch-circuit panelboard to 42. This applies to the total number
of pole spaces, not the physical size of the panel.
4. Which NEC article covers wiring methods for general installations?
A. Article 110
B. Article 200
C. Article 300
D. Article 400
E. Article 500
, C. Article 300 EXPERT RATIONALE: NEC Article 300 covers the general requirements
for all wiring methods used in electrical installations. It includes rules on protection,
support, and installation practices applicable to most wiring systems.
5. What color is typically used for the grounded (neutral) conductor in a
branch circuit?
A. Green
B. Black
C. Red
D. White
E. Blue
D. White EXPERT RATIONALE: Per NEC 200.6, the grounded (neutral) conductor
must be identified by white or gray insulation, or three white stripes on other than green
insulation. Green is reserved for equipment grounding conductors.
6. A 20-ampere branch circuit is required to supply a continuous load. What is
the minimum circuit rating required?
A. 20A
B. 24A
C. 25A
D. 30A
E. 32A
C. 25A EXPERT RATIONALE: Per NEC 210.20(A), branch circuits supplying continuous
loads must be rated at no less than 125% of the continuous load. 20A × 1.25 = 25A
minimum circuit rating.
, 7. What is the maximum allowable voltage drop for a branch circuit under
NEC recommendations?
A. 1%
B. 2%
C. 3%
D. 5%
E. 7%
C. 3% EXPERT RATIONALE: NEC 210.19(A) informational note recommends a
maximum voltage drop of 3% for branch circuits and 5% total for feeders and branch
circuits combined to ensure efficient operation of equipment.
8. Which of the following conductor insulation types is rated for use in wet
locations?
A. TW
B. THHN
C. THW
D. RHH
E. XHHW
C. THW EXPERT RATIONALE: THW insulation is rated for use in both wet and dry
locations and is rated at 75°C. THHN is only rated for dry and damp locations. THW's
"W" designation indicates wet location suitability per NEC Table 310.4.
9. According to the NEC, what is the minimum height for service entrance
conductors above a residential roof with a slope of 4/12 or greater?
A. 3 feet
B. 8 feet
(Journeyman/State) Prep 2026 | NEC Code
Practice Questions, Answers & Detailed
Rationales | Electrical Theory & Exam
Success Guide
• This prep guide contains 200 NEC-based multiple choice questions with
highlighted correct answers and detailed EXPERT RATIONALE to reinforce
understanding of every concept tested on the Journeyman Electrician License Exam.
• Read each question carefully, attempt an answer before checking the correct
option, and study the EXPERT RATIONALE thoroughly — this method builds both
knowledge and exam-passing confidence.
1. What is the standard voltage for a single-phase residential service in the
United States?
A. 120/208V
B. 277/480V
C. 120/240V
D. 240/480V
E. 208/240V
C. 120/240V EXPERT RATIONALE: Standard single-phase residential service in the
US is 120/240V. This is a center-tapped transformer system providing 120V for general
receptacles and lighting, and 240V for larger appliances like dryers and ranges per NEC
Article 230.
2. According to the NEC, what is the minimum burial depth for rigid metal
conduit (RMC) under a residential driveway?
A. 6 inches
B. 12 inches
,C. 18 inches
D. 24 inches
E. 36 inches
B. 12 inches EXPERT RATIONALE: Per NEC Table 300.5, RMC installed under a
residential driveway requires a minimum burial depth of 12 inches. RMC's mechanical
strength allows for shallower burial compared to other wiring methods.
3. What is the maximum number of overcurrent devices permitted in a
lighting and appliance branch-circuit panelboard?
A. 30
B. 42
C. 48
D. 60
E. 84
B. 42 EXPERT RATIONALE: NEC 408.15 limits the number of overcurrent devices in a
lighting and appliance branch-circuit panelboard to 42. This applies to the total number
of pole spaces, not the physical size of the panel.
4. Which NEC article covers wiring methods for general installations?
A. Article 110
B. Article 200
C. Article 300
D. Article 400
E. Article 500
, C. Article 300 EXPERT RATIONALE: NEC Article 300 covers the general requirements
for all wiring methods used in electrical installations. It includes rules on protection,
support, and installation practices applicable to most wiring systems.
5. What color is typically used for the grounded (neutral) conductor in a
branch circuit?
A. Green
B. Black
C. Red
D. White
E. Blue
D. White EXPERT RATIONALE: Per NEC 200.6, the grounded (neutral) conductor
must be identified by white or gray insulation, or three white stripes on other than green
insulation. Green is reserved for equipment grounding conductors.
6. A 20-ampere branch circuit is required to supply a continuous load. What is
the minimum circuit rating required?
A. 20A
B. 24A
C. 25A
D. 30A
E. 32A
C. 25A EXPERT RATIONALE: Per NEC 210.20(A), branch circuits supplying continuous
loads must be rated at no less than 125% of the continuous load. 20A × 1.25 = 25A
minimum circuit rating.
, 7. What is the maximum allowable voltage drop for a branch circuit under
NEC recommendations?
A. 1%
B. 2%
C. 3%
D. 5%
E. 7%
C. 3% EXPERT RATIONALE: NEC 210.19(A) informational note recommends a
maximum voltage drop of 3% for branch circuits and 5% total for feeders and branch
circuits combined to ensure efficient operation of equipment.
8. Which of the following conductor insulation types is rated for use in wet
locations?
A. TW
B. THHN
C. THW
D. RHH
E. XHHW
C. THW EXPERT RATIONALE: THW insulation is rated for use in both wet and dry
locations and is rated at 75°C. THHN is only rated for dry and damp locations. THW's
"W" designation indicates wet location suitability per NEC Table 310.4.
9. According to the NEC, what is the minimum height for service entrance
conductors above a residential roof with a slope of 4/12 or greater?
A. 3 feet
B. 8 feet
