Electrician License Exam (Journeyman / State) Prep – Real Practice
Questions, Answers & Detailed Rationales (Updated 2026) | NEC
Code Requirements, Electrical Theory & Ohm’s Law, Wiring Methods &
Installation, Circuit Calculations & Load Sizing, Residential & Commercial
Systems, Motors & Controls, Blueprint Reading, Troubleshooting, OSHA
Safety & Licensing Review
Question 1: According to NEC Article 110.26, what is the minimum required working
space depth in front of electrical equipment operating at 480V to ground with
exposed live parts on one side and grounded parts on the other side?
A. 3 feet
B. 4 feet
C. 6 feet
D. 8 feet
CORRECT ANSWER: A. 3 feet
Rationale: NEC Table 110.26(A)(1) specifies minimum working space depths based on
voltage and conditions. For equipment operating at 480V (nominal) to ground with
Condition 1 (exposed live parts on one side and grounded parts on the other), the
minimum depth required is 3 feet. This ensures safe access for qualified personnel
during maintenance and operation.
Question 2: What is the maximum allowable voltage drop for a branch circuit
supplying power to a receptacle outlet, as recommended by the NEC for efficient
operation?
A. 2%
B. 3%
C. 5%
D. 10%
CORRECT ANSWER: B. 3%
Rationale: While the NEC does not enforce voltage drop as a mandatory requirement,
Informational Note No. 2 to NEC 210.19(A) recommends that branch circuit conductors
be sized to prevent a voltage drop exceeding 3%. This recommendation ensures
efficient operation of connected equipment and prevents performance issues,
particularly for motors and sensitive electronics.
Question 3: Which NEC Article specifically addresses the installation requirements
for grounding and bonding of electrical systems?
A. Article 210
B. Article 230
C. Article 250
D. Article 310
CORRECT ANSWER: C. Article 250
,Rationale: NEC Article 250 is dedicated entirely to grounding and bonding
requirements. It covers system grounding, equipment grounding, grounding electrode
systems, bonding of enclosures and raceways, and sizing of grounding conductors.
Mastery of Article 250 is critical for journeyman electricians to ensure safety and code
compliance.
Question 4: When installing Type NM cable (Romex) through a bored hole in a wood
framing member, what is the minimum distance the cable must be maintained
from the nearest edge of the stud to avoid requiring a steel protection plate?
A. 1 inch
B. 1¼ inches
C. 1½ inches
D. 2 inches
CORRECT ANSWER: B. 1¼ inches
Rationale: NEC 300.4(A)(1) requires that cables or raceways installed through holes in
framing members be protected from damage by nails or screws. If the cable is installed
less than 1¼ inches from the nearest edge of the stud, a steel plate at least 1/16 inch
thick must be installed to protect the cable. Maintaining 1¼ inches or more eliminates
this requirement.
Question 5: What is the minimum size copper equipment grounding conductor
required for a 60-ampere circuit protected by a circuit breaker, according to NEC
Table 250.122?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
CORRECT ANSWER: C. 10 AWG
Rationale: NEC Table 250.122 specifies the minimum size equipment grounding
conductors based on the rating of the overcurrent protective device. For a 60-ampere
circuit, the table requires a minimum 10 AWG copper equipment grounding conductor.
This ensures adequate fault-current carrying capacity to facilitate overcurrent device
operation during a ground fault.
Question 6: In a dwelling unit, what is the maximum spacing allowed between
receptacle outlets along the floor line of any wall space, as required by NEC
210.52(A)(1)?
A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
,CORRECT ANSWER: D. 12 feet
Rationale: NEC 210.52(A)(1) requires that in dwelling units, receptacle outlets be
installed so that no point along the floor line of any wall space is more than 6 feet from a
receptacle. This effectively limits the maximum spacing between receptacles to 12 feet,
ensuring convenient access to power and reducing the need for extension cords.
Question 7: Which of the following conductor insulation types is suitable for use in
wet locations according to NEC Table 310.104(A)?
A. THHN
B. THWN-2
C. XHHW
D. Both B and C
CORRECT ANSWER: D. Both B and C
Rationale: NEC Table 310.104(A) lists conductor insulation types and their permitted
uses. THWN-2 and XHHW are both rated for wet locations. THHN alone is only rated for
dry locations unless dual-rated as THHN/THWN-2. Journeyman electricians must verify
insulation ratings before installing conductors in damp or wet environments to ensure
code compliance and safety.
Question 8: What is the required ampacity adjustment factor when installing nine
current-carrying conductors in a single raceway, according to NEC Table
310.15(C)(1)?
A. 50%
B. 70%
C. 80%
D. 90%
CORRECT ANSWER: B. 70%
Rationale: NEC Table 310.15(C)(1) provides adjustment factors for more than three
current-carrying conductors in a raceway or cable. For 7-9 current-carrying conductors,
the adjustment factor is 70%. This derating accounts for increased heat buildup,
preventing conductor insulation damage and ensuring safe operation under load.
Question 9: Which NEC article governs the installation requirements for motors
and motor circuits?
A. Article 420
B. Article 430
C. Article 440
D. Article 450
CORRECT ANSWER: B. Article 430
, Rationale: NEC Article 430 comprehensively covers motors, motor circuits, controllers,
and overcurrent protection. It includes requirements for motor branch circuits, feeder
calculations, overload protection, disconnecting means, and grounding. Mastery of
Article 430 is essential for journeyman electricians working with motor-driven
equipment.
Question 10: What is the minimum burial depth for direct-buried UF cable
supplying a 120V residential branch circuit under a residential driveway, per NEC
Table 300.5?
A. 12 inches
B. 18 inches
C. 24 inches
D. 30 inches
CORRECT ANSWER: B. 18 inches
Rationale: NEC Table 300.5 specifies minimum cover requirements for underground
installations. For UF cable supplying a residential branch circuit rated 120V or less with
GFCI protection, the minimum cover under a residential driveway is 18 inches. This
depth protects the cable from physical damage due to vehicle traffic while maintaining
safety and code compliance.
Question 11: When sizing branch-circuit conductors for a continuous load, what
multiplier must be applied to the load calculation per NEC 210.19(A)(1)?
A. 100%
B. 125%
C. 150%
D. 200%
CORRECT ANSWER: B. 125%
Rationale: NEC 210.19(A)(1) requires that branch-circuit conductors supplying
continuous loads (operating for 3 hours or more) be sized at no less than 125% of the
continuous load. This accounts for sustained heat generation and prevents conductor
insulation degradation, ensuring long-term safety and reliability.
Question 12: Which of the following is NOT an acceptable method for identifying an
equipment grounding conductor per NEC 250.119?
A. Green insulation
B. Green with yellow stripe insulation
C. Bare copper
D. White insulation with green tape at terminations
CORRECT ANSWER: D. White insulation with green tape at terminations
Rationale: NEC 250.119 permits equipment grounding conductors to be identified by
green insulation, green with one or more yellow stripes, or bare construction. Using
Questions, Answers & Detailed Rationales (Updated 2026) | NEC
Code Requirements, Electrical Theory & Ohm’s Law, Wiring Methods &
Installation, Circuit Calculations & Load Sizing, Residential & Commercial
Systems, Motors & Controls, Blueprint Reading, Troubleshooting, OSHA
Safety & Licensing Review
Question 1: According to NEC Article 110.26, what is the minimum required working
space depth in front of electrical equipment operating at 480V to ground with
exposed live parts on one side and grounded parts on the other side?
A. 3 feet
B. 4 feet
C. 6 feet
D. 8 feet
CORRECT ANSWER: A. 3 feet
Rationale: NEC Table 110.26(A)(1) specifies minimum working space depths based on
voltage and conditions. For equipment operating at 480V (nominal) to ground with
Condition 1 (exposed live parts on one side and grounded parts on the other), the
minimum depth required is 3 feet. This ensures safe access for qualified personnel
during maintenance and operation.
Question 2: What is the maximum allowable voltage drop for a branch circuit
supplying power to a receptacle outlet, as recommended by the NEC for efficient
operation?
A. 2%
B. 3%
C. 5%
D. 10%
CORRECT ANSWER: B. 3%
Rationale: While the NEC does not enforce voltage drop as a mandatory requirement,
Informational Note No. 2 to NEC 210.19(A) recommends that branch circuit conductors
be sized to prevent a voltage drop exceeding 3%. This recommendation ensures
efficient operation of connected equipment and prevents performance issues,
particularly for motors and sensitive electronics.
Question 3: Which NEC Article specifically addresses the installation requirements
for grounding and bonding of electrical systems?
A. Article 210
B. Article 230
C. Article 250
D. Article 310
CORRECT ANSWER: C. Article 250
,Rationale: NEC Article 250 is dedicated entirely to grounding and bonding
requirements. It covers system grounding, equipment grounding, grounding electrode
systems, bonding of enclosures and raceways, and sizing of grounding conductors.
Mastery of Article 250 is critical for journeyman electricians to ensure safety and code
compliance.
Question 4: When installing Type NM cable (Romex) through a bored hole in a wood
framing member, what is the minimum distance the cable must be maintained
from the nearest edge of the stud to avoid requiring a steel protection plate?
A. 1 inch
B. 1¼ inches
C. 1½ inches
D. 2 inches
CORRECT ANSWER: B. 1¼ inches
Rationale: NEC 300.4(A)(1) requires that cables or raceways installed through holes in
framing members be protected from damage by nails or screws. If the cable is installed
less than 1¼ inches from the nearest edge of the stud, a steel plate at least 1/16 inch
thick must be installed to protect the cable. Maintaining 1¼ inches or more eliminates
this requirement.
Question 5: What is the minimum size copper equipment grounding conductor
required for a 60-ampere circuit protected by a circuit breaker, according to NEC
Table 250.122?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
CORRECT ANSWER: C. 10 AWG
Rationale: NEC Table 250.122 specifies the minimum size equipment grounding
conductors based on the rating of the overcurrent protective device. For a 60-ampere
circuit, the table requires a minimum 10 AWG copper equipment grounding conductor.
This ensures adequate fault-current carrying capacity to facilitate overcurrent device
operation during a ground fault.
Question 6: In a dwelling unit, what is the maximum spacing allowed between
receptacle outlets along the floor line of any wall space, as required by NEC
210.52(A)(1)?
A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
,CORRECT ANSWER: D. 12 feet
Rationale: NEC 210.52(A)(1) requires that in dwelling units, receptacle outlets be
installed so that no point along the floor line of any wall space is more than 6 feet from a
receptacle. This effectively limits the maximum spacing between receptacles to 12 feet,
ensuring convenient access to power and reducing the need for extension cords.
Question 7: Which of the following conductor insulation types is suitable for use in
wet locations according to NEC Table 310.104(A)?
A. THHN
B. THWN-2
C. XHHW
D. Both B and C
CORRECT ANSWER: D. Both B and C
Rationale: NEC Table 310.104(A) lists conductor insulation types and their permitted
uses. THWN-2 and XHHW are both rated for wet locations. THHN alone is only rated for
dry locations unless dual-rated as THHN/THWN-2. Journeyman electricians must verify
insulation ratings before installing conductors in damp or wet environments to ensure
code compliance and safety.
Question 8: What is the required ampacity adjustment factor when installing nine
current-carrying conductors in a single raceway, according to NEC Table
310.15(C)(1)?
A. 50%
B. 70%
C. 80%
D. 90%
CORRECT ANSWER: B. 70%
Rationale: NEC Table 310.15(C)(1) provides adjustment factors for more than three
current-carrying conductors in a raceway or cable. For 7-9 current-carrying conductors,
the adjustment factor is 70%. This derating accounts for increased heat buildup,
preventing conductor insulation damage and ensuring safe operation under load.
Question 9: Which NEC article governs the installation requirements for motors
and motor circuits?
A. Article 420
B. Article 430
C. Article 440
D. Article 450
CORRECT ANSWER: B. Article 430
, Rationale: NEC Article 430 comprehensively covers motors, motor circuits, controllers,
and overcurrent protection. It includes requirements for motor branch circuits, feeder
calculations, overload protection, disconnecting means, and grounding. Mastery of
Article 430 is essential for journeyman electricians working with motor-driven
equipment.
Question 10: What is the minimum burial depth for direct-buried UF cable
supplying a 120V residential branch circuit under a residential driveway, per NEC
Table 300.5?
A. 12 inches
B. 18 inches
C. 24 inches
D. 30 inches
CORRECT ANSWER: B. 18 inches
Rationale: NEC Table 300.5 specifies minimum cover requirements for underground
installations. For UF cable supplying a residential branch circuit rated 120V or less with
GFCI protection, the minimum cover under a residential driveway is 18 inches. This
depth protects the cable from physical damage due to vehicle traffic while maintaining
safety and code compliance.
Question 11: When sizing branch-circuit conductors for a continuous load, what
multiplier must be applied to the load calculation per NEC 210.19(A)(1)?
A. 100%
B. 125%
C. 150%
D. 200%
CORRECT ANSWER: B. 125%
Rationale: NEC 210.19(A)(1) requires that branch-circuit conductors supplying
continuous loads (operating for 3 hours or more) be sized at no less than 125% of the
continuous load. This accounts for sustained heat generation and prevents conductor
insulation degradation, ensuring long-term safety and reliability.
Question 12: Which of the following is NOT an acceptable method for identifying an
equipment grounding conductor per NEC 250.119?
A. Green insulation
B. Green with yellow stripe insulation
C. Bare copper
D. White insulation with green tape at terminations
CORRECT ANSWER: D. White insulation with green tape at terminations
Rationale: NEC 250.119 permits equipment grounding conductors to be identified by
green insulation, green with one or more yellow stripes, or bare construction. Using
