NASCLA Electrical Contractor. Exam – National
Association of State Contractors Licensing Agencies |
2025/2026 Actual Questions and Verified Answers.
EXAM OVERVIEW
This comprehensive study guide is designed for candidates preparing for the NASCLA Electrical
Contractor Licensing Examination for the 2025/2026 testing cycle. The NASCLA exam is
accepted by multiple states as a reciprocal licensing examination for electrical contractors.
Exam Structure and Content:
• Total Questions: Varies by state (typically 80-110 questions)
• Time Limit: Usually 4-6 hours
• Reference Allowed: 2023 National Electrical Code (NEC) and approved reference materials
• Passing Score: Typically 70-75% depending on jurisdiction
Major Content Areas Covered:
• General Electrical Knowledge: Theory, formulas, conversions, and electrical principles
• Wiring and Protection: Conductors, overcurrent protection, grounding, and bonding
• Wiring Methods: Raceways, boxes, fittings, cables, and installation requirements
• Equipment: Motors, transformers, panels, switches, and receptacles
• Load Calculations: Services, feeders, branch circuits, and dwelling/commercial
calculations
• Special Occupancies: Hazardous locations, health care facilities, pools, and spas
• Business and Law: Contracts, liens, licensing, insurance, and workers' compensation
This guide reflects all 2023 NEC updates and NASCLA examination standards effective for
2025/2026. Each question includes verified correct answers and detailed rationales with code
citations.
Section 1: General Electrical Knowledge (Theory, Calculations, Formulas)
(Questions 1-20)
Q1: What is the total resistance of three 12-ohm resistors connected in parallel?
,A. 4 ohms
B. 36 ohms
C. 4 ohms [CORRECT]
D. 12 ohms
Correct Answer: C
Rationale:
• For parallel resistors: 1/Rt = 1/R1 + 1/R2 + 1/R3
• 1/Rt = 1/12 + 1/12 + 1/12 = 3/12 = 1/4
• Rt = 4 ohms
• This is fundamental Ohm's Law application for parallel circuits (NEC-related electrical
theory)
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. 5.1 kVA
C. 6 kVA [CORRECT]
D. 6 kW
Correct Answer: C
Rationale:
• Apparent Power (S) = Volts × Amps
• S = 240V × 25A = 6,000 VA = 6 kVA
• Real power would be 6 kVA × 0.85 = 5.1 kW, but question asks for apparent power
• Common error: confusing real power (kW) with apparent power (kVA)
Q3: What is the voltage drop percentage for a 120V circuit with 3V drop?
A. 1.5%
B. 2.0%
,C. 2.5% [CORRECT]
D. 3.0%
Correct Answer: C
Rationale:
• Voltage Drop % = (Voltage Drop / System Voltage) × 100
• (3V / 120V) × 100 = 2.5%
• NEC recommends maximum 3% drop on feeders and 5% total (feeder + branch)
• Reference: NEC 210.19(A) Informational Note No. 4
Q4: Convert 75°C to Fahrenheit.
A. 149°F
B. 158°F
C. 167°F [CORRECT]
D. 175°F
Correct Answer: C
Rationale:
• Formula: °F = (°C × 9/5) + 32
• (75 × 9/5) + 32 = 135 + 32 = 167°F
• Temperature conversions are essential for conductor ampacity corrections (NEC 310.16
ambient temperature corrections)
Q5: Three 10-ohm resistors are connected in series to a 120V source. What is the circuit current?
A. 2A
B. 3A
C. 4A [CORRECT]
D. 12A
Correct Answer: C
Rationale:
• Series resistance: Rt = R1 + R2 + R3 = 10 + 10 + 10 = 30 ohms
, • Ohm's Law: I = V/R = 120V / 30Ω = 4A
• Series circuits are fundamental to understanding voltage drop calculations
Q6: What is the power factor of a purely resistive load?
A. 0
B. 0.5
C. 1.0 [CORRECT]
D. 1.414
Correct Answer: C
Rationale:
• Power factor = cos(θ) where θ is the phase angle between voltage and current
• Purely resistive loads have voltage and current in phase (θ = 0°)
• cos(0°) = 1.0
• Inductive loads lag (PF < 1), capacitive loads lead (PF < 1)
Q7: A 480V three-phase system has a line current of 50A. What is the apparent power?
A. 24 kVA
B. 36.9 kVA
C. 41.6 kVA [CORRECT]
D. 48 kVA
Correct Answer: C
Rationale:
• Three-phase apparent power: S = √3 × Vline × Iline
• S = 1.732 × 480V × 50A = 41,568 VA = 41.6 kVA
• Common error: forgetting to multiply by √3 (1.732) for three-phase systems
• Essential for service load calculations per NEC Article 220
Q8: What is the capacitive reactance of a 100μF capacitor at 60 Hz?
Association of State Contractors Licensing Agencies |
2025/2026 Actual Questions and Verified Answers.
EXAM OVERVIEW
This comprehensive study guide is designed for candidates preparing for the NASCLA Electrical
Contractor Licensing Examination for the 2025/2026 testing cycle. The NASCLA exam is
accepted by multiple states as a reciprocal licensing examination for electrical contractors.
Exam Structure and Content:
• Total Questions: Varies by state (typically 80-110 questions)
• Time Limit: Usually 4-6 hours
• Reference Allowed: 2023 National Electrical Code (NEC) and approved reference materials
• Passing Score: Typically 70-75% depending on jurisdiction
Major Content Areas Covered:
• General Electrical Knowledge: Theory, formulas, conversions, and electrical principles
• Wiring and Protection: Conductors, overcurrent protection, grounding, and bonding
• Wiring Methods: Raceways, boxes, fittings, cables, and installation requirements
• Equipment: Motors, transformers, panels, switches, and receptacles
• Load Calculations: Services, feeders, branch circuits, and dwelling/commercial
calculations
• Special Occupancies: Hazardous locations, health care facilities, pools, and spas
• Business and Law: Contracts, liens, licensing, insurance, and workers' compensation
This guide reflects all 2023 NEC updates and NASCLA examination standards effective for
2025/2026. Each question includes verified correct answers and detailed rationales with code
citations.
Section 1: General Electrical Knowledge (Theory, Calculations, Formulas)
(Questions 1-20)
Q1: What is the total resistance of three 12-ohm resistors connected in parallel?
,A. 4 ohms
B. 36 ohms
C. 4 ohms [CORRECT]
D. 12 ohms
Correct Answer: C
Rationale:
• For parallel resistors: 1/Rt = 1/R1 + 1/R2 + 1/R3
• 1/Rt = 1/12 + 1/12 + 1/12 = 3/12 = 1/4
• Rt = 4 ohms
• This is fundamental Ohm's Law application for parallel circuits (NEC-related electrical
theory)
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. 5.1 kVA
C. 6 kVA [CORRECT]
D. 6 kW
Correct Answer: C
Rationale:
• Apparent Power (S) = Volts × Amps
• S = 240V × 25A = 6,000 VA = 6 kVA
• Real power would be 6 kVA × 0.85 = 5.1 kW, but question asks for apparent power
• Common error: confusing real power (kW) with apparent power (kVA)
Q3: What is the voltage drop percentage for a 120V circuit with 3V drop?
A. 1.5%
B. 2.0%
,C. 2.5% [CORRECT]
D. 3.0%
Correct Answer: C
Rationale:
• Voltage Drop % = (Voltage Drop / System Voltage) × 100
• (3V / 120V) × 100 = 2.5%
• NEC recommends maximum 3% drop on feeders and 5% total (feeder + branch)
• Reference: NEC 210.19(A) Informational Note No. 4
Q4: Convert 75°C to Fahrenheit.
A. 149°F
B. 158°F
C. 167°F [CORRECT]
D. 175°F
Correct Answer: C
Rationale:
• Formula: °F = (°C × 9/5) + 32
• (75 × 9/5) + 32 = 135 + 32 = 167°F
• Temperature conversions are essential for conductor ampacity corrections (NEC 310.16
ambient temperature corrections)
Q5: Three 10-ohm resistors are connected in series to a 120V source. What is the circuit current?
A. 2A
B. 3A
C. 4A [CORRECT]
D. 12A
Correct Answer: C
Rationale:
• Series resistance: Rt = R1 + R2 + R3 = 10 + 10 + 10 = 30 ohms
, • Ohm's Law: I = V/R = 120V / 30Ω = 4A
• Series circuits are fundamental to understanding voltage drop calculations
Q6: What is the power factor of a purely resistive load?
A. 0
B. 0.5
C. 1.0 [CORRECT]
D. 1.414
Correct Answer: C
Rationale:
• Power factor = cos(θ) where θ is the phase angle between voltage and current
• Purely resistive loads have voltage and current in phase (θ = 0°)
• cos(0°) = 1.0
• Inductive loads lag (PF < 1), capacitive loads lead (PF < 1)
Q7: A 480V three-phase system has a line current of 50A. What is the apparent power?
A. 24 kVA
B. 36.9 kVA
C. 41.6 kVA [CORRECT]
D. 48 kVA
Correct Answer: C
Rationale:
• Three-phase apparent power: S = √3 × Vline × Iline
• S = 1.732 × 480V × 50A = 41,568 VA = 41.6 kVA
• Common error: forgetting to multiply by √3 (1.732) for three-phase systems
• Essential for service load calculations per NEC Article 220
Q8: What is the capacitive reactance of a 100μF capacitor at 60 Hz?
