Master Electrician Calculation Free Practice Exam

The actual Master Electrician Calculation Exam varies by state but states like Texas includes 33 questions that you need to complete in 170 minutes, aiming for a passing score of 70% or higher. Our free online practice exam reflects this format, drawing randomly from a rich question bank of over 100 questions. You can take the exam endlessly, with a unique test each time to improve your skills without repetition.

Our Master Electrician Calculation practice exam includes questions across all critical calculation areas:

1. Ohm’s Law and Power Formulas

Master the fundamental calculations for current, voltage drop, impedance, and power in both DC and AC circuits.

2. AC Circuit Analysis

Practice calculations involving inductive and reactive loads, power factor correction, reactance, and apparent power measurements.

3. Motor and Generator Calculations

Develop proficiency in determining Full Load Amperage (FLA), appropriate overload protection, breaker sizing, and feeder sizing for motor installations.

4. Service & Feeder Sizing

Apply demand factors according to NEC Articles 220/230/250, calculate wire ampacity correctly, and determine voltage drop for various scenarios.

5. Branch Circuit Requirements

Learn to distinguish between continuous and non-continuous loads, calculate general lighting requirements, and properly size conductors for branch circuits.

6. Conduit Fill & Derating

Master the application of NEC Chapter 9 tables and Article 310.15(B)(3)(a) for conductor adjustment based on conduit fill and ambient temperature.

7. NEC-Specific Application

Each question includes specific NEC Article references, ensuring you’re not just calculating correctly but also applying the proper code sections.

The exam focuses heavily on applied electrical math including but not limited to:

• Ohm’s Law & Power Formulas: Calculating current, voltage, power, impedance.
• AC Circuit Analysis: Inductive/reactive loads, power factor, reactance.
• Motor & Generator Calculations: Full Load Amperage (FLA), overloads, feeder and breaker sizing.
• Service & Feeder Sizing: NEC demand factors, wire ampacity, voltage drop calculations.
• Branch Circuit Calculations: Continuous vs. non-continuous loads, conductor sizing.
• Conduit Fill & Derating: NEC Chapter 9 tables, raceway fill, ambient temperature corrections.
• Real-World Scenarios: Practical troubleshooting and NEC-compliant design decisions.

Each question requires not only calculation skills but also a strong grasp of the 2023 NEC to apply correct code references during scenario analyses.

1. Realistic Exam Simulation

Our online platform replicates the pressure and time constraints of the actual exam environment, helping you develop the time management skills needed to complete calculations efficiently.

2. Focus on Calculation Weaknesses

The calculation portion is where most exam candidates struggle. Our dedicated practice exam focuses specifically on mathematical concepts and code-based calculations.

3. Immediate Feedback and Learning

After completing each practice test, you’ll receive detailed explanations for each question, including the step-by-step calculations and specific NEC references.

4. Alignment with PSI/ICC/State Exams

The structure and question types closely mirror what appears on actual licensing exams administered by PSI, NASCLA, ICC, and state licensing boards.

5. Unlimited Practice with Different Questions

With a question bank of over 100 calculations, you can take the exam multiple times without encountering the same questions repeatedly.

6. Up-to-Date with 2023 NEC

All questions are based on the current 2023 National Electrical Code, ensuring you’re preparing with the most recent code requirements.

Below are examples of the types of calculation questions you might encounter on our practice exam. These reflect the depth and complexity of questions on the official Master Electrician exams:

Question 1: Branch Circuit Calculation

A 120V circuit supplies the following loads: one 1500W heater, two 100W light fixtures, and three 150W receptacles. What is the minimum size circuit breaker required?

A. 15 amperes
B. 20 amperes
C. 25 amperes
D. 30 amperes

Answer: B. 20 amperes

Calculation:
Total Load = 1500W + (2 × 100W) + (3 × 150W) = 1500W + 200W + 450W = 2150W
Current = Power ÷ Voltage = 2150W ÷ 120V = 17.92A
Next standard size circuit breaker: 20A

NEC Reference: Article 210.3 for branch circuit ratings and 210.20(A) for overcurrent protection sizing.

Question 2: Voltage Drop Calculation

A 208V, single-phase motor is located 175 feet from the panel. The motor draws 22 amperes. If the maximum allowable voltage drop is 3%, what is the minimum copper conductor size required?

A. 8 AWG
B. 6 AWG
C. 4 AWG
D. 3 AWG

Answer: C. 4 AWG

Calculation:
Voltage Drop (%) = (2 × K × I × L) ÷ (CM × V) × 100
Where K = 12.9 (for copper), I = 22A, L = 175ft, V = 208V
For 3% drop: 3 = (2 × 12.9 × 22 × 175) ÷ (CM × 208) × 100
CM = (2 × 12.9 × 22 × 175 × 100) ÷ (3 × 208) = 36,575
From NEC Chapter 9, Table 8: 4 AWG has 41,740 CM, which is the next size up.

NEC Reference: Chapter 9, Table 8 for conductor properties and Informative Annex B for voltage drop calculations.

Question 3: Motor Calculation

A 50 HP, 460V, 3-phase motor has a service factor of 1.15 and a nameplate FLA of 65A. What is the minimum size overload protection required?

A. 65A
B. 74.75A
C. 78A
D. 81.25A

Answer: B. 74.75A

Calculation:
Per NEC 430.32(A)(1), for motors with a service factor of 1.15 or greater:
Overload Protection = FLA × 1.15 = 65A × 1.15 = 74.75A

NEC Reference: Article 430.32(A)(1) for motor overload protection.

Question 4: Raceway Fill Calculation

How many 10 AWG THHN conductors can be installed in a 1-inch EMT conduit without exceeding the 40% fill requirement?

A. 9 conductors
B. 12 conductors
C. 15 conductors
D. 18 conductors

Answer: C. 15 conductors

Calculation:
From NEC Chapter 9, Table 4:
1-inch EMT has a 40% fill area of 0.346 square inches
From NEC Chapter 9, Table 5:
10 AWG THHN has an area of 0.0211 square inches
Maximum conductors = 0.346 ÷ 0.0211 = 16.4 (round down to 15)

NEC Reference: NEC Chapter 9, Tables 4 and 5 for conduit fill calculations.

Question 5: Service Load Calculation

A dwelling unit has 1800 square feet of living area, a 12kW electric range, a 5.5kW electric water heater, a 3kW clothes dryer, and a 2.5-ton (24A) central AC unit. What is the minimum service size required?

A. 100A
B. 125A
C. 150A
D. 200A

Answer: D. 200A

Calculation:
General Lighting Load: 1800 sq ft × 3VA = 5400VA
Small Appliance Circuits: 2 × 1500VA = 3000VA
Laundry Circuit: 1 × 1500VA = 1500VA
Total: 9900VA
First 10,000VA at 100%: 9900VA
Remaining at 35%: 0VA
Range (NEC Table 220.55): 8000VA
Water Heater: 5500VA
Dryer: 3000VA
AC: 24A × 240V = 5760VA
Total Calculated Load: 9900VA + 8000VA + 5500VA + 3000VA + 5760VA = 32,160VA
Service Size = 32,160VA ÷ 240V = 134A
Next standard size: 200A (considering future expansion)

NEC Reference: NEC Article 220 for load calculations and 230.79 for service disconnecting means ratings.

Looking to expand your exam preparation? Check out our other free practice exams:

• Free Electrical Code Practice Exam – Test your knowledge of general electrical code requirements
• Free OSHA 1926 Exam – Prepare for construction safety requirements

With a national passing rate of only 32.14% for Master Electrician exams, thorough preparation is essential. Our free Master Electrician Calculation practice exam provides targeted training in the most challenging aspect of the licensing process.

By focusing specifically on calculations aligned with the 2023 NEC, you’ll develop the mathematical proficiency and code application skills needed to pass your state exam with confidence. Start practicing today with our free online exam, and take a significant step toward achieving your Master Electrician license.

Remember, the key to passing the calculation portion is consistent practice with varied problems. Take advantage of our free practice exam with unlimited attempts and different questions each time. Your success as a Master Electrician begins with mastering these calculations!