Electrician License Exam (Journeyman / State) NCLEX Prep Practice
Questions & Answers Study Guide Updated 2026 | 250+ Verified
Questions with Detailed Rationales | Electrical Theory and Ohm’s Law, NEC
Code and Regulations, Wiring Methods and Installation, Circuits and Load
Calculations, Electrical Safety and OSHA Standards, Blueprint Reading
and Schematics, Motors and Controls, Troubleshooting Techniques, Tools
and Equipment, State Licensing Exam Prep | Complete Exam Prep
Resource for Journeyman Electrician License Success
Question 1: According to NEC Article 314.16, what is the maximum number of 12
AWG conductors permitted in a 4-inch square box with a depth of 1.5 inches?
A. 6
B. 9
C. 12
D. 15
CORRECT ANSWER: B. 9
RATIONALE:NEC Table 314.16(A) specifies box fill allowances. A 4-inch square box with
1.5-inch depth has a volume of 21.0 cubic inches. Each 12 AWG conductor requires
2.25 cubic inches of fill space. Dividing 21.0 by 2.25 yields 9.33, which must be rounded
down to 9 conductors maximum per NEC requirements.
Question 2: What is the minimum required working clearance in front of electrical
equipment rated 480V, with exposed live parts on one side and grounded surfaces
on the other, per NEC Article 110.26?
A. 3 feet
B. 3.5 feet
C. 4 feet
D. 6 feet
CORRECT ANSWER: A. 3 feet
RATIONALE:NEC Table 110.26(A)(1) specifies working clearances based on voltage and
conditions. For equipment rated 0-150V to ground, Condition 1 (exposed live parts on
one side, grounded on other) requires 3 feet. Since 480V phase-to-phase is 277V to
ground, which exceeds 150V, but the table shows 3 feet for 0-150V, 3.5 feet for 151-600V
Condition 1. Correction: 480V system has 277V to ground, which falls in 151-600V
range. Condition 1 requires 3.5 feet. Let me recalculate: Actually, 480V three-phase wye
has 277V line-to-ground, which is in the 151-600V category. Table 110.26(A)(1)
Condition 1 (exposed live parts on one side, grounded on other) requires 3.5 feet
minimum. Therefore the correct answer is 3.5 feet.
CORRECT ANSWER: B. 3.5 feet
,RATIONALE:NEC Table 110.26(A)(1) specifies that for systems rated 151-600V to
ground, with Condition 1 (exposed live parts on one side and grounded surfaces on the
other), the minimum working clearance is 3.5 feet. A 480V three-phase wye system has
277V line-to-ground, placing it in this voltage category.
Question 3: Which NEC article specifically addresses the installation requirements
for solar photovoltaic systems?
A. Article 690
B. Article 705
C. Article 710
D. Article 720
CORRECT ANSWER: A. Article 690
RATIONALE:NEC Article 690 is titled "Solar Photovoltaic (PV) Systems" and contains
comprehensive requirements for the installation of solar PV equipment, including wiring
methods, overcurrent protection, disconnecting means, grounding, and labeling
specific to photovoltaic power sources.
Question 4: What is the maximum allowable voltage drop for a branch circuit
supplying a single receptacle outlet, as recommended by NEC informational
notes?
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
for branch circuits, Informational Note No. 2 to NEC 210.19(A)(1) recommends that
branch circuit conductors be sized to prevent a voltage drop exceeding 3% for
reasonable efficiency of operation. The combined voltage drop for feeder and branch
circuit should not exceed 5%.
Question 5: Which of the following conductor types is rated for use in wet locations
at temperatures up to 90°C?
A. THHN
B. THWN
C. THWN-2
D. TW
CORRECT ANSWER: C. THWN-2
RATIONALE:Per NEC Table 310.104(A), THWN-2 conductors are rated for both wet and
dry locations at temperatures up to 90°C. THHN is rated for dry locations only at 90°C.
,THWN is rated for wet locations but only at 75°C. TW is rated for wet locations at 60°C.
The "-2" suffix indicates the 90°C wet location rating.
Question 6: What is the minimum size equipment grounding conductor required for
a 60-ampere circuit using copper conductors, per NEC Table 250.122?
A. 10 AWG
B. 8 AWG
C. 6 AWG
D. 4 AWG
CORRECT ANSWER: A. 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 circuit
protected by a 60-ampere overcurrent device, the table requires a minimum 10 AWG
copper equipment grounding conductor.
Question 7: In a dwelling unit, what is the maximum spacing allowed between
receptacle outlets along the floor line of any wall space, per NEC Article 210.52?
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 receptacle outlets be installed so that no
point along the floor line of any wall space is more than 6 feet from a receptacle outlet.
This effectively mandates a maximum spacing of 12 feet between receptacles, as each
receptacle serves 6 feet in either direction.
Question 8: Which of the following is NOT a required characteristic of a grounding
electrode conductor per NEC Article 250.64?
A. Must be continuous without splices
B. Must be securely fastened to the surface
C. Must be protected from physical damage if smaller than 6 AWG
D. Must be insulated with green-colored insulation
CORRECT ANSWER: D. Must be insulated with green-colored insulation
RATIONALE:NEC 250.64 does not require grounding electrode conductors to have
green insulation. While green insulation is required for equipment grounding
conductors per 250.119, grounding electrode conductors may be bare, covered, or
insulated. If insulated, the insulation is not required to be green. The other options are
required: continuity (250.64(C)), secure fastening (250.64(A)), and protection from
physical damage for conductors smaller than 6 AWG (250.64(B)).
, Question 9: What is the minimum ampacity required for branch circuit conductors
supplying a single motor with a full-load current of 24 amperes, per NEC Article
430.22?
A. 24 amperes
B. 30 amperes
C. 48 amperes
D. 60 amperes
CORRECT ANSWER: B. 30 amperes
RATIONALE:NEC 430.22(A) requires that branch circuit conductors supplying a single
motor have an ampacity of not less than 125% of the motor full-load current rating. For
a motor with 24 amperes full-load current, 24 × 1.25 = 30 amperes minimum conductor
ampacity.
Question 10: Which NEC article covers the requirements for emergency systems in
health care facilities?
A. Article 517
B. Article 700
C. Article 701
D. Article 708
CORRECT ANSWER: A. Article 517
RATIONALE:NEC Article 517, "Health Care Facilities," contains specific requirements
for electrical systems in health care environments, including essential electrical
systems (EES) with emergency, critical, and equipment branches. While Articles 700,
701, and 708 cover emergency, legally required standby, and critical operations power
systems respectively, Article 517 specifically addresses health care facility
applications.
Question 11: What is the maximum number of 60-watt incandescent lighting
fixtures permitted on a 20-ampere, 120-volt branch circuit, assuming continuous
load calculations?
A. 24
B. 32
C. 40
D. 48
CORRECT ANSWER: B. 32
RATIONALE:For continuous loads (operating 3 hours or more), NEC 210.20(A) requires
the overcurrent device to be rated at least 125% of the continuous load. A 20-ampere
circuit allows 20A × 120V = 2400VA maximum. For continuous load, maximum
continuous load is 2400VA ÷ 1.25 = 1920VA. Each 60-watt fixture = 60VA. 1920VA ÷ 60VA
= 32 fixtures maximum.
Questions & Answers Study Guide Updated 2026 | 250+ Verified
Questions with Detailed Rationales | Electrical Theory and Ohm’s Law, NEC
Code and Regulations, Wiring Methods and Installation, Circuits and Load
Calculations, Electrical Safety and OSHA Standards, Blueprint Reading
and Schematics, Motors and Controls, Troubleshooting Techniques, Tools
and Equipment, State Licensing Exam Prep | Complete Exam Prep
Resource for Journeyman Electrician License Success
Question 1: According to NEC Article 314.16, what is the maximum number of 12
AWG conductors permitted in a 4-inch square box with a depth of 1.5 inches?
A. 6
B. 9
C. 12
D. 15
CORRECT ANSWER: B. 9
RATIONALE:NEC Table 314.16(A) specifies box fill allowances. A 4-inch square box with
1.5-inch depth has a volume of 21.0 cubic inches. Each 12 AWG conductor requires
2.25 cubic inches of fill space. Dividing 21.0 by 2.25 yields 9.33, which must be rounded
down to 9 conductors maximum per NEC requirements.
Question 2: What is the minimum required working clearance in front of electrical
equipment rated 480V, with exposed live parts on one side and grounded surfaces
on the other, per NEC Article 110.26?
A. 3 feet
B. 3.5 feet
C. 4 feet
D. 6 feet
CORRECT ANSWER: A. 3 feet
RATIONALE:NEC Table 110.26(A)(1) specifies working clearances based on voltage and
conditions. For equipment rated 0-150V to ground, Condition 1 (exposed live parts on
one side, grounded on other) requires 3 feet. Since 480V phase-to-phase is 277V to
ground, which exceeds 150V, but the table shows 3 feet for 0-150V, 3.5 feet for 151-600V
Condition 1. Correction: 480V system has 277V to ground, which falls in 151-600V
range. Condition 1 requires 3.5 feet. Let me recalculate: Actually, 480V three-phase wye
has 277V line-to-ground, which is in the 151-600V category. Table 110.26(A)(1)
Condition 1 (exposed live parts on one side, grounded on other) requires 3.5 feet
minimum. Therefore the correct answer is 3.5 feet.
CORRECT ANSWER: B. 3.5 feet
,RATIONALE:NEC Table 110.26(A)(1) specifies that for systems rated 151-600V to
ground, with Condition 1 (exposed live parts on one side and grounded surfaces on the
other), the minimum working clearance is 3.5 feet. A 480V three-phase wye system has
277V line-to-ground, placing it in this voltage category.
Question 3: Which NEC article specifically addresses the installation requirements
for solar photovoltaic systems?
A. Article 690
B. Article 705
C. Article 710
D. Article 720
CORRECT ANSWER: A. Article 690
RATIONALE:NEC Article 690 is titled "Solar Photovoltaic (PV) Systems" and contains
comprehensive requirements for the installation of solar PV equipment, including wiring
methods, overcurrent protection, disconnecting means, grounding, and labeling
specific to photovoltaic power sources.
Question 4: What is the maximum allowable voltage drop for a branch circuit
supplying a single receptacle outlet, as recommended by NEC informational
notes?
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
for branch circuits, Informational Note No. 2 to NEC 210.19(A)(1) recommends that
branch circuit conductors be sized to prevent a voltage drop exceeding 3% for
reasonable efficiency of operation. The combined voltage drop for feeder and branch
circuit should not exceed 5%.
Question 5: Which of the following conductor types is rated for use in wet locations
at temperatures up to 90°C?
A. THHN
B. THWN
C. THWN-2
D. TW
CORRECT ANSWER: C. THWN-2
RATIONALE:Per NEC Table 310.104(A), THWN-2 conductors are rated for both wet and
dry locations at temperatures up to 90°C. THHN is rated for dry locations only at 90°C.
,THWN is rated for wet locations but only at 75°C. TW is rated for wet locations at 60°C.
The "-2" suffix indicates the 90°C wet location rating.
Question 6: What is the minimum size equipment grounding conductor required for
a 60-ampere circuit using copper conductors, per NEC Table 250.122?
A. 10 AWG
B. 8 AWG
C. 6 AWG
D. 4 AWG
CORRECT ANSWER: A. 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 circuit
protected by a 60-ampere overcurrent device, the table requires a minimum 10 AWG
copper equipment grounding conductor.
Question 7: In a dwelling unit, what is the maximum spacing allowed between
receptacle outlets along the floor line of any wall space, per NEC Article 210.52?
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 receptacle outlets be installed so that no
point along the floor line of any wall space is more than 6 feet from a receptacle outlet.
This effectively mandates a maximum spacing of 12 feet between receptacles, as each
receptacle serves 6 feet in either direction.
Question 8: Which of the following is NOT a required characteristic of a grounding
electrode conductor per NEC Article 250.64?
A. Must be continuous without splices
B. Must be securely fastened to the surface
C. Must be protected from physical damage if smaller than 6 AWG
D. Must be insulated with green-colored insulation
CORRECT ANSWER: D. Must be insulated with green-colored insulation
RATIONALE:NEC 250.64 does not require grounding electrode conductors to have
green insulation. While green insulation is required for equipment grounding
conductors per 250.119, grounding electrode conductors may be bare, covered, or
insulated. If insulated, the insulation is not required to be green. The other options are
required: continuity (250.64(C)), secure fastening (250.64(A)), and protection from
physical damage for conductors smaller than 6 AWG (250.64(B)).
, Question 9: What is the minimum ampacity required for branch circuit conductors
supplying a single motor with a full-load current of 24 amperes, per NEC Article
430.22?
A. 24 amperes
B. 30 amperes
C. 48 amperes
D. 60 amperes
CORRECT ANSWER: B. 30 amperes
RATIONALE:NEC 430.22(A) requires that branch circuit conductors supplying a single
motor have an ampacity of not less than 125% of the motor full-load current rating. For
a motor with 24 amperes full-load current, 24 × 1.25 = 30 amperes minimum conductor
ampacity.
Question 10: Which NEC article covers the requirements for emergency systems in
health care facilities?
A. Article 517
B. Article 700
C. Article 701
D. Article 708
CORRECT ANSWER: A. Article 517
RATIONALE:NEC Article 517, "Health Care Facilities," contains specific requirements
for electrical systems in health care environments, including essential electrical
systems (EES) with emergency, critical, and equipment branches. While Articles 700,
701, and 708 cover emergency, legally required standby, and critical operations power
systems respectively, Article 517 specifically addresses health care facility
applications.
Question 11: What is the maximum number of 60-watt incandescent lighting
fixtures permitted on a 20-ampere, 120-volt branch circuit, assuming continuous
load calculations?
A. 24
B. 32
C. 40
D. 48
CORRECT ANSWER: B. 32
RATIONALE:For continuous loads (operating 3 hours or more), NEC 210.20(A) requires
the overcurrent device to be rated at least 125% of the continuous load. A 20-ampere
circuit allows 20A × 120V = 2400VA maximum. For continuous load, maximum
continuous load is 2400VA ÷ 1.25 = 1920VA. Each 60-watt fixture = 60VA. 1920VA ÷ 60VA
= 32 fixtures maximum.
