NYC Master Electrician Licensing
Examination ACTUAL EXAM 2026/2027 |
Complete Exam Material | Verified Q&A |
Pass Guaranteed - A+ Graded
Section 1: General Electrical Theory & Calculations (Questions 1-20)
Q1: What is the total resistance when three 12-ohm resistors are connected in parallel?
A. 36 ohms
B. 9 ohms
C. 4 ohms [CORRECT]
D. 12 ohms
Correct Answer: C
Rationale: For parallel resistors, 1/Rt = 1/R1 + 1/R2 + 1/R3 = 1/12 + 1/12 + 1/12 = 3/12 = 1/4. Therefore
Rt = 4 ohms. Distractor A (36 ohms) incorrectly adds resistances in series. Distractor B (9 ohms) uses
wrong formula 12 × 3/4.
Q2: A single-phase motor draws 25A at 240V with a power factor of 0.85. What is the apparent power?
A. 4.25 kW
B. 6.0 kVA [CORRECT]
C. 5.1 kVA
D. 6.0 kW
Correct Answer: B
Rationale: Apparent power (S) = V × I = 240V × 25A = 6,000 VA = 6.0 kVA. Note that real power (P) = V × I
× pf = 5.1 kW. Distractor C (5.1 kVA) confuses apparent power with real power. Distractor A (4.25 kW)
incorrectly applies power factor twice.
Q3: According to NEC 2023, what is the minimum size THHN copper conductor permitted for a 20A
branch circuit?
,A. 14 AWG
B. 12 AWG [CORRECT]
C. 10 AWG
D. 8 AWG
Correct Answer: B
Rationale: NEC Table 310.16 shows 20A circuits require minimum 12 AWG copper for general branch
circuits. Distractor A (14 AWG) is only rated for 15A. Distractor C (10 AWG) is oversized and
unnecessary cost.
Q4: In a DC circuit, a 10-ohm resistor carries 5A. What is the power dissipated?
A. 50W
B. 250W [CORRECT]
C. 500W
D. 25W
Correct Answer: B
Rationale: P = I² × R = (5A)² × 10Ω = 25 × 10 = 250W. Alternatively, V = I×R = 50V, then P = V×I = 250W.
Distractor A (50W) incorrectly calculates V×I with wrong values. Distractor C (500W) doubles the correct
answer.
Q5: Three-phase power calculation: A 480V three-phase system supplies a load drawing 30A per phase
with 0.9 power factor. What is the real power?
A. 12.47 kW
B. 22.46 kW [CORRECT]
C. 24.94 kW
D. 14.4 kW
Correct Answer: B
Rationale: P = √3 × V × I × pf = 1.732 × 480V × 30A × 0.9 = 22,455 W ≈ 22.46 kW. Distractor C (24.94 kW)
calculates apparent power without power factor. Distractor A (12.47 kW) uses single-phase formula
incorrectly.
Q6: What is the voltage drop percentage for a 120V circuit with 3V drop?
A. 4%
B. 2.5% [CORRECT]
,C. 3%
D. 5%
Correct Answer: B
Rationale: %VD = (VD / Source Voltage) × 100 = (3V / 120V) × 100 = 2.5%. Distractor A (4%) incorrectly
uses 240V as denominator. Distractor C (3%) confuses drop value with percentage.
Q7: A transformer has 480V primary and 120V secondary with 40 primary turns. How many secondary
turns?
A. 160 turns
B. 10 turns [CORRECT]
C. 20 turns
D. 40 turns
Correct Answer: B
Rationale: Turns ratio = Voltage ratio. Ns/Np = Vs/Vp. Ns = Np × (Vs/Vp) = 40 × (120/480) = 40 × 0.25 =
10 turns. Distractor A (160) inverts the ratio. Distractor C (20) uses square root incorrectly.
Q8: What is the total capacitance of two 100μF capacitors in series?
A. 200μF
B. 100μF
C. 50μF [CORRECT]
D. 25μF
Correct Answer: C
Rationale: For series capacitors, 1/Ct = 1/C1 + 1/C2 = 1/100 + 1/100 = 2/100. Ct = 50μF. Distractor A
(200μF) is parallel connection. Distractor D (25μF) incorrectly divides by 4.
Q9: A 15kW, 240V single-phase load operates continuously. What is the minimum branch circuit
ampacity required?
A. 62.5A
B. 78.125A [CORRECT]
C. 52.08A
D. 90A
Correct Answer: B
Rationale: I = P/V = 15,000W/240V = 62.5A. Continuous load requires 125%: 62.5A × 1.25 = 78.125A
, (NEC 210.19(A)(1)). Distractor A (62.5A) ignores continuous load multiplier. Distractor C (52.08A) inverts
the calculation.
Q10: What is the impedance of a series R-L circuit with R=30Ω and XL=40Ω?
A. 70Ω
B. 50Ω [CORRECT]
C. 10Ω
D. 1200Ω
Correct Answer: B
Rationale: Z = √(R² + XL²) = √(900 + 1600) = √2500 = 50Ω. Distractor A (70Ω) adds values directly.
Distractor D (1200Ω) multiplies values incorrectly.
Q11: A 3-phase, 480V delta-connected motor draws 50A line current. What is the phase current?
A. 50A
B. 86.6A
C. 28.87A [CORRECT]
D. 100A
Correct Answer: C
Rationale: In delta connection, I_line = √3 × I_phase. Therefore I_phase = I_line/√3 = 50/1.732 = 28.87A.
Distractor A (50A) confuses line and phase current. Distractor B (86.6A) multiplies instead of divides.
Q12: What is the reactance of a 0.1H inductor at 60Hz?
A. 37.7Ω [CORRECT]
B. 6.28Ω
C. 377Ω
D. 60Ω
Correct Answer: A
Rationale: XL = 2πfL = 2 × 3.1416 × 60 × 0.1 = 37.7Ω. Distractor B (6.28Ω) uses 10Hz. Distractor C (377Ω)
uses 1H instead of 0.1H.
Q13: A 100kVA transformer at 80% power factor delivers how much real power?
Examination ACTUAL EXAM 2026/2027 |
Complete Exam Material | Verified Q&A |
Pass Guaranteed - A+ Graded
Section 1: General Electrical Theory & Calculations (Questions 1-20)
Q1: What is the total resistance when three 12-ohm resistors are connected in parallel?
A. 36 ohms
B. 9 ohms
C. 4 ohms [CORRECT]
D. 12 ohms
Correct Answer: C
Rationale: For parallel resistors, 1/Rt = 1/R1 + 1/R2 + 1/R3 = 1/12 + 1/12 + 1/12 = 3/12 = 1/4. Therefore
Rt = 4 ohms. Distractor A (36 ohms) incorrectly adds resistances in series. Distractor B (9 ohms) uses
wrong formula 12 × 3/4.
Q2: A single-phase motor draws 25A at 240V with a power factor of 0.85. What is the apparent power?
A. 4.25 kW
B. 6.0 kVA [CORRECT]
C. 5.1 kVA
D. 6.0 kW
Correct Answer: B
Rationale: Apparent power (S) = V × I = 240V × 25A = 6,000 VA = 6.0 kVA. Note that real power (P) = V × I
× pf = 5.1 kW. Distractor C (5.1 kVA) confuses apparent power with real power. Distractor A (4.25 kW)
incorrectly applies power factor twice.
Q3: According to NEC 2023, what is the minimum size THHN copper conductor permitted for a 20A
branch circuit?
,A. 14 AWG
B. 12 AWG [CORRECT]
C. 10 AWG
D. 8 AWG
Correct Answer: B
Rationale: NEC Table 310.16 shows 20A circuits require minimum 12 AWG copper for general branch
circuits. Distractor A (14 AWG) is only rated for 15A. Distractor C (10 AWG) is oversized and
unnecessary cost.
Q4: In a DC circuit, a 10-ohm resistor carries 5A. What is the power dissipated?
A. 50W
B. 250W [CORRECT]
C. 500W
D. 25W
Correct Answer: B
Rationale: P = I² × R = (5A)² × 10Ω = 25 × 10 = 250W. Alternatively, V = I×R = 50V, then P = V×I = 250W.
Distractor A (50W) incorrectly calculates V×I with wrong values. Distractor C (500W) doubles the correct
answer.
Q5: Three-phase power calculation: A 480V three-phase system supplies a load drawing 30A per phase
with 0.9 power factor. What is the real power?
A. 12.47 kW
B. 22.46 kW [CORRECT]
C. 24.94 kW
D. 14.4 kW
Correct Answer: B
Rationale: P = √3 × V × I × pf = 1.732 × 480V × 30A × 0.9 = 22,455 W ≈ 22.46 kW. Distractor C (24.94 kW)
calculates apparent power without power factor. Distractor A (12.47 kW) uses single-phase formula
incorrectly.
Q6: What is the voltage drop percentage for a 120V circuit with 3V drop?
A. 4%
B. 2.5% [CORRECT]
,C. 3%
D. 5%
Correct Answer: B
Rationale: %VD = (VD / Source Voltage) × 100 = (3V / 120V) × 100 = 2.5%. Distractor A (4%) incorrectly
uses 240V as denominator. Distractor C (3%) confuses drop value with percentage.
Q7: A transformer has 480V primary and 120V secondary with 40 primary turns. How many secondary
turns?
A. 160 turns
B. 10 turns [CORRECT]
C. 20 turns
D. 40 turns
Correct Answer: B
Rationale: Turns ratio = Voltage ratio. Ns/Np = Vs/Vp. Ns = Np × (Vs/Vp) = 40 × (120/480) = 40 × 0.25 =
10 turns. Distractor A (160) inverts the ratio. Distractor C (20) uses square root incorrectly.
Q8: What is the total capacitance of two 100μF capacitors in series?
A. 200μF
B. 100μF
C. 50μF [CORRECT]
D. 25μF
Correct Answer: C
Rationale: For series capacitors, 1/Ct = 1/C1 + 1/C2 = 1/100 + 1/100 = 2/100. Ct = 50μF. Distractor A
(200μF) is parallel connection. Distractor D (25μF) incorrectly divides by 4.
Q9: A 15kW, 240V single-phase load operates continuously. What is the minimum branch circuit
ampacity required?
A. 62.5A
B. 78.125A [CORRECT]
C. 52.08A
D. 90A
Correct Answer: B
Rationale: I = P/V = 15,000W/240V = 62.5A. Continuous load requires 125%: 62.5A × 1.25 = 78.125A
, (NEC 210.19(A)(1)). Distractor A (62.5A) ignores continuous load multiplier. Distractor C (52.08A) inverts
the calculation.
Q10: What is the impedance of a series R-L circuit with R=30Ω and XL=40Ω?
A. 70Ω
B. 50Ω [CORRECT]
C. 10Ω
D. 1200Ω
Correct Answer: B
Rationale: Z = √(R² + XL²) = √(900 + 1600) = √2500 = 50Ω. Distractor A (70Ω) adds values directly.
Distractor D (1200Ω) multiplies values incorrectly.
Q11: A 3-phase, 480V delta-connected motor draws 50A line current. What is the phase current?
A. 50A
B. 86.6A
C. 28.87A [CORRECT]
D. 100A
Correct Answer: C
Rationale: In delta connection, I_line = √3 × I_phase. Therefore I_phase = I_line/√3 = 50/1.732 = 28.87A.
Distractor A (50A) confuses line and phase current. Distractor B (86.6A) multiplies instead of divides.
Q12: What is the reactance of a 0.1H inductor at 60Hz?
A. 37.7Ω [CORRECT]
B. 6.28Ω
C. 377Ω
D. 60Ω
Correct Answer: A
Rationale: XL = 2πfL = 2 × 3.1416 × 60 × 0.1 = 37.7Ω. Distractor B (6.28Ω) uses 10Hz. Distractor C (377Ω)
uses 1H instead of 0.1H.
Q13: A 100kVA transformer at 80% power factor delivers how much real power?
