200+ Free Master Electrician Practice Questions

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Two sets of 500 kcmil THHN copper conductors are installed in parallel in a single raceway. The load is 480 volts, three-phase, non-linear with significant third harmonic content. What is the required ampacity adjustment factor for these conductors?

C. 85%

B. 80%

D. 90%

A. 70%

to track

2026 Statistics

Key Facts: Master Electrician Exam

75%

ICC Master Passing Score

ICC support guidance

100

Questions

ICC bulletin

5 hrs

Time Limit

ICC bulletin

$120

Pearson VUE Fee

ICC bulletin

2023

R16 NEC Edition

ICC current exam list

Not published

First-Time Pass Rate

Official ICC sources opened

The current ICC R16/T16/G16 Master Electrician exams have 100 multiple-choice questions, a 5-hour open-book time limit, a $120 Pearson VUE exam fee, and require 75% correct for ICC Master Electrician contractor/trades passing. ICC is not a licensing agency, so candidates must verify jurisdiction-specific exam code, NEC edition, work-hour eligibility, allowed references, contractor/business requirements, and post-exam licensing rules before registering.

Sample Master Electrician Practice Questions

Try these sample questions to test your Master Electrician exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 200+ question experience with AI tutoring.

1According to Ohm's Law, what is the current in a 120-volt circuit with a resistance of 24 ohms?

A.A. 2.5 amperes

B.B. 5 amperes

C.C. 10 amperes

D.D. 20 amperes

Explanation: Ohm's Law states that I = V/R. With V = 120 volts and R = 24 ohms: I = 120/24 = 5 amperes. This fundamental formula is essential for all electrical calculations and is referenced throughout the NEC for circuit analysis and conductor sizing.

2What does the NEC define as a "continuous load"?

A.A. A load that operates for at least 8 hours per day

B.B. A load where the maximum current is expected to continue for 3 hours or more

C.C. Any load connected to a 480-volt system

D.D. A load that operates 24 hours per day, 7 days per week

Explanation: According to NEC Article 100 (Definitions), a continuous load is defined as "a load where the maximum current is expected to continue for 3 hours or more." This definition is critical for applying the 125% multiplier requirements found in NEC 210.19(A)(1) for branch circuits and NEC 215.2(A)(1) for feeders.

3In a standard 120/240-volt single-phase residential service, what is the phase relationship between the two ungrounded conductors?

A.A. They are in phase with each other

B.B. They are 180 degrees out of phase with each other

C.C. They are 120 degrees out of phase with each other

D.D. They are 90 degrees out of phase with each other

Explanation: In a single-phase 120/240-volt system derived from a center-tapped transformer, the two ungrounded (hot) conductors are 180 degrees out of phase. This phase relationship allows for 240 volts between the two ungrounded conductors while providing 120 volts from either ungrounded conductor to the grounded (neutral) conductor.

4What is the power consumed by a 20-ampere, 120-volt resistive load?

A.A. 1,440 watts

B.B. 2,400 watts

C.C. 4,800 watts

D.D. 6,000 watts

Explanation: Using the power formula P = I × V, where I = 20 amperes and V = 120 volts: P = 20 × 120 = 2,400 watts. For resistive loads (like heaters and incandescent lighting), the power factor is 1.0, so no power factor correction is needed. This calculation is fundamental for load calculations per NEC Article 220.

5What is the minimum size grounding electrode conductor required for a 200-ampere service using 2/0 AWG copper service conductors?

A.A. 8 AWG copper

B.B. 6 AWG copper

C.C. 4 AWG copper

D.D. 2 AWG copper

Explanation: According to NEC Table 250.66, for ungrounded service conductors sized 2/0 AWG or 3/0 AWG copper, the minimum grounding electrode conductor size is 6 AWG copper (or 4 AWG aluminum). This ensures adequate capacity to safely carry fault currents to the grounding electrode system.

6What is the maximum standard ampere rating for an overcurrent protective device that can protect a 14 AWG copper conductor?

A.A. 10 amperes

B.B. 15 amperes

C.C. 20 amperes

D.D. 25 amperes

Explanation: NEC 240.4(D)(2) specifies that unless specifically permitted in 240.4(E) or (G), the overcurrent protection shall not exceed 15 amperes for 14 AWG copper conductors. This is a critical safety requirement to prevent conductor overheating and potential fire hazards.

7According to NEC 314.16, how many volume allowances are required for each yoke or strap containing one or more devices?

A.A. One volume allowance

B.B. Two volume allowances

C.C. Three volume allowances

D.D. Four volume allowances

Explanation: NEC 314.16(B)(4) states that for each yoke or strap containing one or more devices or equipment, a double volume allowance based on the largest conductor connected to the device(s) shall be counted. This means each switch, receptacle, or similar device mounted on a yoke counts as two conductor volumes.

8In a residential dwelling unit, what is the maximum spacing allowed between general-purpose receptacle outlets along a wall?

A.A. 6 feet

B.B. 8 feet

C.C. 10 feet

D.D. 12 feet

Explanation: NEC 210.52(A)(1) requires that in dwelling units, receptacles shall be installed such that no point measured horizontally along the floor line of any wall space is more than 6 feet (1.8 m) from a receptacle outlet. This equates to a maximum 12-foot spacing between receptacles, ensuring that a 6-foot appliance cord can reach a receptacle anywhere along the wall.

9What is the generally recommended maximum percentage voltage drop for a combination of branch circuit and feeder?

A.A. 2%

B.B. 3%

C.C. 5%

D.D. 10%

Explanation: NEC 210.19(A)(1) Informational Note No. 4 recommends that the maximum combined voltage drop for both feeders and branch circuits should not exceed 5%, with not more than a 3% drop in either the feeder or the branch circuit alone. While this is a recommendation and not a strict code requirement, it ensures efficient operation of electrical equipment.

10In a DC circuit with a 12-volt battery powering three 4-ohm resistors connected in series, what is the total circuit current?

A.A. 0.5 amperes

B.B. 1.0 amperes

C.C. 2.0 amperes

D.D. 3.0 amperes

Explanation: For series resistors, the total resistance is the sum: R_total = 4 + 4 + 4 = 12 ohms. Using Ohm's Law I = V/R = 12/12 = 1.0 amperes. In series circuits, current remains constant throughout while voltage divides across each resistor.

About the Master Electrician Exam

The ICC National Standard Master Electrician exams are open-book contractor/trades exams used by some licensing jurisdictions to evaluate NEC-centered master-level electrical competency. R16 is based on the 2023 NEC, T16 on the 2020 NEC, and G16 on the 2017 NEC, while state and local authorities decide which exam, references, work hours, business requirements, and license requirements apply.

Questions

100 scored questions

Time Limit

5 hours

Passing Score

75% for ICC Master Electrician contractor/trades exams; verify jurisdiction rules

Exam Fee

$120 ICC Pearson VUE exam fee (International Code Council (ICC) / Pearson VUE; licensing authority controls license issuance)

Master Electrician Exam Content Outline

12%

General Knowledge

Electrical theory, general load calculations, code definitions and terms, plan reading, and reference navigation.

16%

Services and Service Equipment

Services and fault current, service load calculations, service equipment, service conductors, transformers, system grounding and bonding, and temporary service wiring.

Feeders

Feeder load calculations and equipment grounding decisions.

16%

Branch Circuits and Conductors

Branch-circuit calculations, overcurrent protection, conductors, required outlets, GFCI/AFCI protection, and equipment grounding.

19%

Wiring Methods and Materials

Raceway installations, underground wiring methods, boxes and enclosures, cabinets, panelboards, switchboards, clearance and guarding, flexible cords, and cables.

10%

Equipment and Devices

Luminaires, receptacles, switches, appliances, utilization equipment, and heating/cooling equipment.

Control Devices

Switches, disconnects, controllers, and control-device application logic.

Motors and Generators

Motor and generator installation, conductors, overcurrent protection, disconnecting means, grounding, bonding, and generator application rules.

12%

Special Occupancies, Equipment, and Conditions

Special occupancies, pools and similar installations, mobile home/RV parks, data processing equipment, miscellaneous special equipment, emergency systems, signaling, and fire alarm systems.

How to Pass the Master Electrician Exam

What You Need to Know

Passing score: 75% for ICC Master Electrician contractor/trades exams; verify jurisdiction rules
Exam length: 100 questions
Time limit: 5 hours
Exam fee: $120 ICC Pearson VUE exam fee

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

Master Electrician Study Tips from Top Performers

1Confirm your jurisdiction and exact ICC exam code before buying references because R16, T16, and G16 use different NEC editions.

2Build a code-index workflow for definitions, service rules, conductor tables, grounding and bonding, wiring methods, and special occupancies.

3Practice service and feeder calculations until you can set up the load, demand factor, conductor, neutral, and overcurrent-protection sequence without guessing.

4Study grounding and bonding as a fault-current path system, not as isolated vocabulary.

5Treat wiring methods as a high-weight domain: raceway selection, box fill, enclosure selection, underground methods, working space, and guarding all matter.

6Practice motor and generator questions by separating conductor sizing, overload protection, short-circuit/ground-fault protection, disconnecting means, and controller requirements.

7Use timed open-book drills because the ICC bulletin warns candidates will not have time to look up every answer.

8Answer every question because ICC contractor/trades exams have no guessing penalty.

Frequently Asked Questions

Is there one national master electrician license exam?

No. ICC offers national contractor/trades master electrician exams such as R16, T16, and G16, but ICC is not a licensing agency. State, city, county, or local licensing authorities decide which exam and which additional work-hour, application, business, bonding, insurance, and license requirements apply.

How many questions are on the ICC Master Electrician exam?

The February 23, 2026 ICC National Contractor/Trades Examination Information Bulletin lists R16 and T16 Master Electrician as 100 multiple-choice questions with a 5-hour open-book time limit. The current national exam list also identifies G16 as a 2017 NEC master electrician option.

What NEC edition is used on the master electrician exam?

The current ICC national contractor exams list shows R16-N based on the 2023 NEC, T16-N based on the 2020 NEC, and G16-N based on the 2017 NEC. Candidates must verify the exact exam code and code edition required by their licensing jurisdiction before studying from a code book.

What score do I need to pass the ICC Master Electrician exam?

ICC passing-score guidance says the Master Electrician contractor/trades exam requires 75% correct to pass. Candidates should still read the relevant bulletin or contact the licensing agency because a jurisdiction can set its own minimum passing requirement.

Is the master electrician exam open book?

The ICC R16/T16/G16 national master electrician exams are listed as open book. ICC rules limit references and testing materials, so candidates should use the current exam catalog, bulletin, and Pearson VUE or PRONTO rules before test day.

Can I use a calculator on the ICC contractor/trades exam?

ICC FAQ guidance allows a battery-operated, nonprogrammable calculator for computer-based exams if it cannot store exam information and has no ribbon or paper printing. PRONTO guidance allows a basic four-function nonprogrammable calculator.

What are the largest master electrician exam domains?

For ICC R16/T16, Wiring Methods and Materials is the largest domain at 19%, followed by Services and Service Equipment at 16%, Branch Circuits and Conductors at 16%, General Knowledge at 12%, and Special Occupancies, Equipment, and Conditions at 12%.