Wisconsin Master Electrician Exam
Newest (2026 Update) Actual Practice
Questions – Set 100 Most Common
Exam Questions And Answers In Details
100% Verified Exam Highly
Recommendable For Grade A+
Question 1
A 240V single-phase load draws 18A. What is the minimum circuit breaker rating
required under standard sizing rules?
A. 18A
B. 20A
C. 25A
D. 30A
Answer: ✔ B [20A]
Rationale: A circuit breaker is selected at 125% for continuous loads and must
match standard sizes; 18A rounds up to the next standard rating of 20A.
Question 2
A 1-phase transformer has a primary voltage of 480V and secondary voltage of
240V. What is the turns ratio?
A. 1:1
B. 2:1
C. 3:1
D. 4:1
Answer: ✔ B [2:1]
,Rationale: Voltage ratio equals turns ratio; 480/240 = 2, so the transformer is
2:1.
Question 3
Which conductor is typically required to be insulated in a grounded system?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper
D. Ground rod conductor
Answer: ✔ B [Neutral conductor]
Rationale: The neutral (grounded conductor) must be insulated in most systems
except specific grounding points.
Question 4
A motor draws 22A continuous load. What is the minimum conductor ampacity
required?
A. 22A
B. 25A
C. 27.5A
D. 30A
Answer: ✔ C [27.5A]
Rationale: Motor conductors are sized at 125% of full load current: 22 × 1.25 =
27.5A.
Question 5
What is the primary purpose of a GFCI device?
A. Overcurrent protection
B. Arc fault protection
C. Ground-fault protection for personnel
D. Surge suppression
Answer: ✔ C [Ground-fault protection for personnel]
Rationale: GFCIs protect people by detecting imbalance in current between hot
and neutral.
, Question 6
A 120V circuit supplies 1440W load. What is the current?
A. 10A
B. 12A
C. 14A
D. 16A
Answer: ✔ B [12A]
Rationale: I = P/V = 1440/120 = 12A.
Question 7
What is the maximum voltage drop recommended for branch circuits?
A. 1%
B. 3%
C. 5%
D. 10%
Answer: ✔ B [3%]
Rationale: NEC recommends 3% max voltage drop for branch circuits for
efficiency.
Question 8
Which device protects against arc faults in dwelling units?
A. AFCI
B. GFCI
C. MCCB
D. SPD
Answer: ✔ A [AFCI]
Rationale: Arc Fault Circuit Interrupters detect dangerous arcing conditions.
Question 9
A 3-phase system has line voltage of 208V. What is phase voltage in wye
connection?
A. 120V
B. 127V
C. 208V
Newest (2026 Update) Actual Practice
Questions – Set 100 Most Common
Exam Questions And Answers In Details
100% Verified Exam Highly
Recommendable For Grade A+
Question 1
A 240V single-phase load draws 18A. What is the minimum circuit breaker rating
required under standard sizing rules?
A. 18A
B. 20A
C. 25A
D. 30A
Answer: ✔ B [20A]
Rationale: A circuit breaker is selected at 125% for continuous loads and must
match standard sizes; 18A rounds up to the next standard rating of 20A.
Question 2
A 1-phase transformer has a primary voltage of 480V and secondary voltage of
240V. What is the turns ratio?
A. 1:1
B. 2:1
C. 3:1
D. 4:1
Answer: ✔ B [2:1]
,Rationale: Voltage ratio equals turns ratio; 480/240 = 2, so the transformer is
2:1.
Question 3
Which conductor is typically required to be insulated in a grounded system?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper
D. Ground rod conductor
Answer: ✔ B [Neutral conductor]
Rationale: The neutral (grounded conductor) must be insulated in most systems
except specific grounding points.
Question 4
A motor draws 22A continuous load. What is the minimum conductor ampacity
required?
A. 22A
B. 25A
C. 27.5A
D. 30A
Answer: ✔ C [27.5A]
Rationale: Motor conductors are sized at 125% of full load current: 22 × 1.25 =
27.5A.
Question 5
What is the primary purpose of a GFCI device?
A. Overcurrent protection
B. Arc fault protection
C. Ground-fault protection for personnel
D. Surge suppression
Answer: ✔ C [Ground-fault protection for personnel]
Rationale: GFCIs protect people by detecting imbalance in current between hot
and neutral.
, Question 6
A 120V circuit supplies 1440W load. What is the current?
A. 10A
B. 12A
C. 14A
D. 16A
Answer: ✔ B [12A]
Rationale: I = P/V = 1440/120 = 12A.
Question 7
What is the maximum voltage drop recommended for branch circuits?
A. 1%
B. 3%
C. 5%
D. 10%
Answer: ✔ B [3%]
Rationale: NEC recommends 3% max voltage drop for branch circuits for
efficiency.
Question 8
Which device protects against arc faults in dwelling units?
A. AFCI
B. GFCI
C. MCCB
D. SPD
Answer: ✔ A [AFCI]
Rationale: Arc Fault Circuit Interrupters detect dangerous arcing conditions.
Question 9
A 3-phase system has line voltage of 208V. What is phase voltage in wye
connection?
A. 120V
B. 127V
C. 208V
