South Carolina 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+
1. A 240V, single-phase load draws 18A. What is the minimum copper
conductor ampacity required under continuous load conditions?
A. 18A
B. 20A
C. 22.5A
D. 30A
Answer: D ✓ (30A)
Rationale: Continuous loads require 125% sizing; 18A × 1.25 = 22.5A, next
standard conductor rating is 30A.
2. According to NEC grounding rules, the main purpose of grounding is to:
A. Increase voltage stability
B. Provide a low-resistance fault path
C. Reduce conductor size
D. Improve load efficiency
Answer: B ✓ (Provide a low-resistance fault path)
Rationale: Grounding ensures fault current returns safely to the source to trip
overcurrent protection.
3. A 3-phase motor is rated at 10 HP, 230V. Approximate full-load current is:
A. 24A
B. 28A
, C. 32A
D. 40A
Answer: B ✓ (28A)
Rationale: NEC tables list ~28 amps for 10 HP at 230V three-phase.
4. What is the maximum number of current-carrying conductors allowed in a
conduit before derating is required?
A. 2
B. 3
C. 4
D. More than 3
Answer: D ✓ (More than 3)
Rationale: Derating applies when more than 3 current-carrying conductors are
installed together.
5. A GFCI device is primarily designed to protect against:
A. Overload
B. Short circuit
C. Ground-fault shock hazard
D. Voltage drop
Answer: C ✓ (Ground-fault shock hazard)
Rationale: GFCIs detect imbalance between hot and neutral indicating leakage
current.
6. A 120V circuit supplies 1440W. What is the current?
A. 10A
B. 12A
C. 14A
D. 16A
Answer: B ✓ (12A)
Rationale: I = P/V = 1440/120 = 12A.
, 7. Minimum burial depth for a residential 120V PVC conduit is typically:
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: C ✓ (18 inches)
Rationale: NEC typically requires 18 inches for residential branch circuits in PVC.
8. A 30A breaker protects a circuit. Maximum continuous load allowed is:
A. 24A
B. 25A
C. 27A
D. 30A
Answer: B ✓ (24A)
Rationale: 30A × 80% = 24A continuous load limit.
9. Which device protects equipment from overcurrent?
A. GFCI
B. AFCI
C. Circuit breaker
D. Transformer
Answer: C ✓ (Circuit breaker)
Rationale: Breakers interrupt current during overloads or short circuits.
10.Voltage drop becomes most critical in circuits longer than:
A. 50 ft
B. 75 ft
C. 100 ft
D. 200 ft
Answer: D ✓ (200 ft)
Rationale: Long runs increase resistance and voltage drop issues.
Newest (2026 Update) Actual Practice
Questions – Set 100 Most Common Exam
Questions And Answers In Details 100%
Verified Exam Highly Recommendable For
Grade A+
1. A 240V, single-phase load draws 18A. What is the minimum copper
conductor ampacity required under continuous load conditions?
A. 18A
B. 20A
C. 22.5A
D. 30A
Answer: D ✓ (30A)
Rationale: Continuous loads require 125% sizing; 18A × 1.25 = 22.5A, next
standard conductor rating is 30A.
2. According to NEC grounding rules, the main purpose of grounding is to:
A. Increase voltage stability
B. Provide a low-resistance fault path
C. Reduce conductor size
D. Improve load efficiency
Answer: B ✓ (Provide a low-resistance fault path)
Rationale: Grounding ensures fault current returns safely to the source to trip
overcurrent protection.
3. A 3-phase motor is rated at 10 HP, 230V. Approximate full-load current is:
A. 24A
B. 28A
, C. 32A
D. 40A
Answer: B ✓ (28A)
Rationale: NEC tables list ~28 amps for 10 HP at 230V three-phase.
4. What is the maximum number of current-carrying conductors allowed in a
conduit before derating is required?
A. 2
B. 3
C. 4
D. More than 3
Answer: D ✓ (More than 3)
Rationale: Derating applies when more than 3 current-carrying conductors are
installed together.
5. A GFCI device is primarily designed to protect against:
A. Overload
B. Short circuit
C. Ground-fault shock hazard
D. Voltage drop
Answer: C ✓ (Ground-fault shock hazard)
Rationale: GFCIs detect imbalance between hot and neutral indicating leakage
current.
6. A 120V circuit supplies 1440W. What is the current?
A. 10A
B. 12A
C. 14A
D. 16A
Answer: B ✓ (12A)
Rationale: I = P/V = 1440/120 = 12A.
, 7. Minimum burial depth for a residential 120V PVC conduit is typically:
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: C ✓ (18 inches)
Rationale: NEC typically requires 18 inches for residential branch circuits in PVC.
8. A 30A breaker protects a circuit. Maximum continuous load allowed is:
A. 24A
B. 25A
C. 27A
D. 30A
Answer: B ✓ (24A)
Rationale: 30A × 80% = 24A continuous load limit.
9. Which device protects equipment from overcurrent?
A. GFCI
B. AFCI
C. Circuit breaker
D. Transformer
Answer: C ✓ (Circuit breaker)
Rationale: Breakers interrupt current during overloads or short circuits.
10.Voltage drop becomes most critical in circuits longer than:
A. 50 ft
B. 75 ft
C. 100 ft
D. 200 ft
Answer: D ✓ (200 ft)
Rationale: Long runs increase resistance and voltage drop issues.
