Wisconsin Master Electrician Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. According to the National Electrical Code (NEC), what is the primary
purpose of overcurrent protection?
A. Prevent voltage drop
B. Improve power factor
C. Protect conductors and equipment from excessive current
D. Increase circuit efficiency
Answer: C. Protect conductors and equipment from excessive current
Rationale: Overcurrent protective devices safeguard conductors and
equipment from overheating and damage caused by overloads, short
circuits, and ground faults.
2. Which NEC article primarily covers grounding and bonding
requirements?
,A. Article 250
B. Article 110
C. Article 300
D. Article 430
Answer: A. Article 250
Rationale: NEC Article 250 establishes requirements for grounding,
bonding, grounding electrodes, and equipment grounding conductors.
3. What is the minimum working space depth for equipment operating at
151–600 volts with exposed live parts on one side and grounded
surfaces on the other?
A. 2 feet
B. 3 feet
C. 4 feet
D. 5 feet
Answer: B. 3 feet
Rationale: NEC 110.26 specifies a minimum working clearance of 3 feet
under these conditions.
4. Conductors used for grounding are generally identified by which
insulation color?
,A. Black
B. Red
C. Green or bare
D. Blue
Answer: C. Green or bare
Rationale: Equipment grounding conductors are identified by green
insulation, green with yellow stripes, or no insulation.
5. Which device protects people primarily from electric shock?
A. Standard circuit breaker
B. Fuse
C. Ground-Fault Circuit Interrupter (GFCI)
D. Disconnect switch
Answer: C. Ground-Fault Circuit Interrupter (GFCI)
Rationale: GFCIs detect ground-fault currents and quickly disconnect power
to reduce shock hazards.
6. The ampacity of a conductor is primarily determined by:
A. Voltage rating
B. Size, insulation type, and installation conditions
, C. Manufacturer's warranty
D. Circuit length only
Answer: B. Size, insulation type, and installation conditions
Rationale: Ampacity depends on conductor size, insulation temperature
rating, ambient temperature, and installation method.
7. What does "continuous load" mean?
A. Any load lasting over 30 minutes
B. A load expected to continue for 3 hours or more
C. A temporary construction load
D. A load connected permanently
Answer: B. A load expected to continue for 3 hours or more
Rationale: NEC defines a continuous load as one expected to operate at
maximum current for three hours or longer.
8. Branch circuits supplying continuous loads must generally be sized to
at least:
A. 100%
B. 110%
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. According to the National Electrical Code (NEC), what is the primary
purpose of overcurrent protection?
A. Prevent voltage drop
B. Improve power factor
C. Protect conductors and equipment from excessive current
D. Increase circuit efficiency
Answer: C. Protect conductors and equipment from excessive current
Rationale: Overcurrent protective devices safeguard conductors and
equipment from overheating and damage caused by overloads, short
circuits, and ground faults.
2. Which NEC article primarily covers grounding and bonding
requirements?
,A. Article 250
B. Article 110
C. Article 300
D. Article 430
Answer: A. Article 250
Rationale: NEC Article 250 establishes requirements for grounding,
bonding, grounding electrodes, and equipment grounding conductors.
3. What is the minimum working space depth for equipment operating at
151–600 volts with exposed live parts on one side and grounded
surfaces on the other?
A. 2 feet
B. 3 feet
C. 4 feet
D. 5 feet
Answer: B. 3 feet
Rationale: NEC 110.26 specifies a minimum working clearance of 3 feet
under these conditions.
4. Conductors used for grounding are generally identified by which
insulation color?
,A. Black
B. Red
C. Green or bare
D. Blue
Answer: C. Green or bare
Rationale: Equipment grounding conductors are identified by green
insulation, green with yellow stripes, or no insulation.
5. Which device protects people primarily from electric shock?
A. Standard circuit breaker
B. Fuse
C. Ground-Fault Circuit Interrupter (GFCI)
D. Disconnect switch
Answer: C. Ground-Fault Circuit Interrupter (GFCI)
Rationale: GFCIs detect ground-fault currents and quickly disconnect power
to reduce shock hazards.
6. The ampacity of a conductor is primarily determined by:
A. Voltage rating
B. Size, insulation type, and installation conditions
, C. Manufacturer's warranty
D. Circuit length only
Answer: B. Size, insulation type, and installation conditions
Rationale: Ampacity depends on conductor size, insulation temperature
rating, ambient temperature, and installation method.
7. What does "continuous load" mean?
A. Any load lasting over 30 minutes
B. A load expected to continue for 3 hours or more
C. A temporary construction load
D. A load connected permanently
Answer: B. A load expected to continue for 3 hours or more
Rationale: NEC defines a continuous load as one expected to operate at
maximum current for three hours or longer.
8. Branch circuits supplying continuous loads must generally be sized to
at least:
A. 100%
B. 110%
