2021 Edition

Master Electrician Practice Test

Take this free practice test of typical questions that may be encountered on most Master Electrician’s licensing exams.

The subject matter covered in most electrical licensing examinations is: Grounding and bonding, Overcurrent protection, Wiring methods and installation, Boxes and fittings, Services and equipment, Motors, Special occupancies, Load calculations, Lighting, Appliances, Box and raceway fill, Hazardous locations, Trade knowledge and Electrical theory.

For complete practice, try the Master Electrican Practice Exam Kit with 300 questions and fully explained answers.

This free test is based on the 2017 National Electric Code (NEC). With Tests.com, you have the option to purchase a practice test kit based on the 2014, 2017 or 2020 NEC Codes. Check with your local code official to determine which code applies to your location.


1. The optional method of calculation for dwelling units is reserved for ___.
2. When calculating the service-entrance conductors of a farm where all the buildings, including the dwelling, are supplied from a common service, the second largest individual load in the group shall be calculated at _____.
3. The entire area of a service pit located in a commercial major repair garage that is not provided with mechanical ventilation is classified as a _____ location.
4. The MAXIMUM distance conduit seals are permitted to be installed from an enclosure that houses devices that produces arcs or high-temperatures in a Class I, Division 1 location is _____.
5. Where three (3) switches are grouped or ganged in an outlet box without permanent barriers, the voltage between the adjacent switches shall NOT exceed _____.
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6. In order to determine the adequate size of a junction box containing size 4 AWG THWN copper conductors, the volume allowance, in cubic inches, required per conductor is _____.
7. Given: You are to install an underground run of trade size 2 in. Schedule 40 PVC conduit containing 120/240-volt, single-phase service-entrance conductors supplying a one-family dwelling. The PVC will not cross under any public streets, roads, driveways or alleys. The conduit is to have a burial depth of at LEAST _____ from final grade.
8. Where an eye-bolt is provided as a means of attachment of 120/240-volt, single-phase residential service-drop conductors, in no case shall this point of attachment be less than _____ above finished grade.
9. Given: You are to install four (4) size 350 kcmil THWN copper conductors in a run of rigid metal conduit (RMC). What is the MINIMUM trade size RMC required to enclose the conductors for this installation?
10. Where size 2 AWG THWN/THHN copper conductors, protected by a 100 ampere rated circuit breaker, are enclosed in a Schedule 40 PVC conduit to supply an air-conditioning unit, what is the MINIMUM size copper equipment grounding conductor required for this installation?
11. As a general rule, switches not over 1,000-volts containing fuses and circuit breakers shall be readily accessible and installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than _____ above the floor more working platform.
12. Underground service conductors of not over 1,000-volts that are not encased in concrete and that are buried 18 inches or more below grade, shall have their location identified by a warning ribbon that is placed in the trench at least _____ above the underground installation.
13. Where the sole support of an outdoor installed Type FS box that contains devices or supports luminaires is two (2) underground buried threaded intermediate metal conduits (IMC) or rigid metal conduits (RMC) that emerge from ground, the NEC requires the box to be no more than _____ from the point where the conduit emerges from the ground.
14. As a general rule regarding solar photovoltaic (PV) systems, supply-side conductor connections for PV systems must terminate in an overcurrent protection device that's within no more than ___ of the point of interconnection to the local electric utility.
15. Calculate the minimum demand load, in amperes, on the ungrounded service-entrance conductors for a recreational vehicle park that has 28 RV sites all with 50-ampere outlets at each RV site. Supply system is single-phase, 120/240 volts.
16. Conduit seals shall be installed at no more than _____ from the entrance of an enclosure that contains arcing or sparking equipment or only splices, taps or terminals where located in Class I, Division 1 hazardous locations.
17. When building a temporary service at a construction site _____ receptacles must be GFCI protected.

I. 125-volt, 15- and 20-ampere
II. 250-volt, 20- and 30-ampere
18. Where it is necessary to install more than one (1) ground rod used as a grounding electrode, the ground rods shall be spaced not less than _____ apart.
19. Where a transformer supplies a single-phase, 120/240-volt, 600 ampere service, the transformer should have a kVA rating of at least _____.
20. Metal conduit installed in indoor wet locations must have a minimum airspace clearance of _____ between the conduit and the wall or supporting surface.

Master Electrician Practice Exam

Quality starts with who wrote the material.
Our practice exam writer
Ray Holder
Certified Electrical Trade Instructor & Electrician License Exam Expert

Ray Holder Journeyman Electrician Practice Exam

Ray has worked in the electrical industry for over 45 years as an apprentice, journeyman, master, field engineer, estimator, business manager, contractor, inspector, consultant and instructor.

He holds a Bachelor of Science degree in Occupational Education and a lifetime Vocational Education teaching certificate from the Texas Education Agency.

Ray is a certified instructor of electrical trades. His classes are presented in a simplified, easy-to-understand format for electricians. Ray is currently the Director of Education for Electrical Seminars, Inc.

He is an active member of the International Association of Electrical Inspectors and a retired member of the International Brotherhood of Electrical Workers