Ohio Master Electrician Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
Q1. What is the minimum size copper grounding electrode conductor
required for a 200-amp residential service?
A. 4 AWG
B. 4 AWG
C. 6 AWG
D. 8 AWG
Rationale: NEC Table 250.66 requires a 4 AWG copper grounding electrode
conductor for a 200A service.
Q2. The NEC is updated every how many years?
A. 2 years
B. 3 years
C. 4 years
,D. 5 years
Rationale: The NFPA revises and publishes the NEC on a 3-year cycle.
Q3. What is the maximum number of conductors allowed in a 1-inch EMT
conduit with #12 THHN wires, assuming 90°C insulation?
A. 13
B. 16
C. 26
D. 30
Rationale: NEC Chapter 9, Table 1 and Annex C allow up to 26 #12 THHN
conductors in a 1-inch EMT.
Q4. Which NEC article covers branch circuits?
A. Article 220
B. Article 210
C. Article 240
D. Article 310
Rationale: Branch circuits are addressed in Article 210 of the NEC.
Q5. What is the minimum burial depth for a direct-buried UF cable under
residential property with GFCI protection?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
,Rationale: NEC 300.5 requires UF cable with GFCI protection to be buried at
least 12 inches deep.
Q6. What is the maximum allowed voltage drop on a branch circuit
according to NEC recommendations?
A. 3%
B. 3%
C. 5%
D. 10%
Rationale: NEC recommends not exceeding 3% voltage drop on a branch
circuit for efficiency.
Q7. What is the standard ampacity of #4/0 copper THHN at 75°C?
A. 175A
B. 195A
C. 205A
D. 230A
Rationale: NEC Table 310.16 lists #4/0 copper THHN at 230 amps at 75°C.
Q8. Which overcurrent device is required to protect a motor branch circuit?
A. Switch
B. Fuse only
C. Circuit breaker or fuses
D. GFCI
Rationale: NEC 430.52 permits branch circuits for motors to be protected
by circuit breakers or fuses.
, Q9. What is the maximum load on a 20-amp branch circuit supplying
continuous loads?
A. 20A
B. 18A
C. 16A
D. 15A
Rationale: NEC 210.20(A) requires continuous loads to be derated to 125%,
so max load = 16A.
Q10. A receptacle installed in a bathroom must be protected by which of the
following?
A. AFCI
B. GFCI
C. Dual function breaker
D. Overcurrent relay
Rationale: NEC 210.8 requires GFCI protection in bathrooms.
Q11. What is the maximum height for a residential service disconnect
handle?
A. 5 ft
B. 5 ft 6 in
C. 6 ft 7 in
D. 7 ft
Rationale: NEC 230.70(A)(1) sets the maximum handle height at 6 ft 7 in.
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
Q1. What is the minimum size copper grounding electrode conductor
required for a 200-amp residential service?
A. 4 AWG
B. 4 AWG
C. 6 AWG
D. 8 AWG
Rationale: NEC Table 250.66 requires a 4 AWG copper grounding electrode
conductor for a 200A service.
Q2. The NEC is updated every how many years?
A. 2 years
B. 3 years
C. 4 years
,D. 5 years
Rationale: The NFPA revises and publishes the NEC on a 3-year cycle.
Q3. What is the maximum number of conductors allowed in a 1-inch EMT
conduit with #12 THHN wires, assuming 90°C insulation?
A. 13
B. 16
C. 26
D. 30
Rationale: NEC Chapter 9, Table 1 and Annex C allow up to 26 #12 THHN
conductors in a 1-inch EMT.
Q4. Which NEC article covers branch circuits?
A. Article 220
B. Article 210
C. Article 240
D. Article 310
Rationale: Branch circuits are addressed in Article 210 of the NEC.
Q5. What is the minimum burial depth for a direct-buried UF cable under
residential property with GFCI protection?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
,Rationale: NEC 300.5 requires UF cable with GFCI protection to be buried at
least 12 inches deep.
Q6. What is the maximum allowed voltage drop on a branch circuit
according to NEC recommendations?
A. 3%
B. 3%
C. 5%
D. 10%
Rationale: NEC recommends not exceeding 3% voltage drop on a branch
circuit for efficiency.
Q7. What is the standard ampacity of #4/0 copper THHN at 75°C?
A. 175A
B. 195A
C. 205A
D. 230A
Rationale: NEC Table 310.16 lists #4/0 copper THHN at 230 amps at 75°C.
Q8. Which overcurrent device is required to protect a motor branch circuit?
A. Switch
B. Fuse only
C. Circuit breaker or fuses
D. GFCI
Rationale: NEC 430.52 permits branch circuits for motors to be protected
by circuit breakers or fuses.
, Q9. What is the maximum load on a 20-amp branch circuit supplying
continuous loads?
A. 20A
B. 18A
C. 16A
D. 15A
Rationale: NEC 210.20(A) requires continuous loads to be derated to 125%,
so max load = 16A.
Q10. A receptacle installed in a bathroom must be protected by which of the
following?
A. AFCI
B. GFCI
C. Dual function breaker
D. Overcurrent relay
Rationale: NEC 210.8 requires GFCI protection in bathrooms.
Q11. What is the maximum height for a residential service disconnect
handle?
A. 5 ft
B. 5 ft 6 in
C. 6 ft 7 in
D. 7 ft
Rationale: NEC 230.70(A)(1) sets the maximum handle height at 6 ft 7 in.
