Common Electrician's Licensing Exam Questions.


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  • NEC Article ______ defines breakers and fuses.

    According to NEC Article 100, a device that opens and closes a circuit by nonautomatic means automatically closes for a predetermined overcurrent.

    Annex _____ of NEC covers conduit fill.

    Annex C of NEC covers conduit and tubing fill for conductors and fixture wire fill.

    NEMA stands for National Electrical Manufacturers Association

    True - NEMA is the acronym for National Electrical Manufacturers Association.

    What does it mean when a receptacle has "NEMA 5-20R" on it?

    A receptacle with NEMA 5-20R on it has an amperes rating of 20, will take a NEMA-5-15P or NEMA-5-20P plug, and has a voltage rating of 125.

    NEC Tables 310-10 through 310-21 provide information on.

    The sizes of copper and aluminum wire, as well as the coating of wire that has fewer than three current carrying wires in a cable or conduit or that is buried in the earth.

    Which NEC tables(s) cover(s) the fill of metal boxes?

    The fill of metal boxes appears in NEC Tables 314.6 A and B.

    NEC Article _____ address EMT.

    NEC Article 358 covers EMT.

    Which NEC articles cover the installation requirements for RMC, IMC, and EMT?

    NEC Articles 342, 344, and 358 outline the installation requirements of RMC, IMC, and EMT.

    IN NEC 2008, what does Table 370.6A cover?

    Shows in two columns (milimeters and inches), how many wires in trade size you can place in a box.

    What NEC table would you go to to find trade size of conduit and raceway size?

    Chapter 9, Table 4 outlines trade size of conduit as well as raceway size.

    NEC Articles _____ and _____ covers metallic and non-metallic raceways in buildings.

    NEC Article 386 covers metallic or metal raceway; NEC Article 388 covers PVC pipe.

    The Panel Board requirements for Application in Construction appear in NEC Article?

    NEC Article 408 covers panel board applications.

    The smaller kitchen counter requiring a receptacle is _____ inches.

    A 12in. counter requires a receptacle because it holds small appliances.

    What new code is needed for protection in all habitable spaces?

    According to new codes, ARC fault protection is needed many additional parts of the house.

    A 12-foot hallway requires one receptacle to meet code. (True or False)

    True, One is required, Two are suggested.

    NEC Article 100 is dedicated to?


    The main ground on a service is a(n) _____.

    Ground Rod

    What does NEC Section 250-28A require?

    A main bonding jumper and a system bonding jumper.

    NEC section 250-28A provides information on what material can be used for a main bonding jumper. (True or False)


    A bonding screw is what color?

    A bonding screw is green.

    A subpanel requires a bonding screw? (True or False)

    False, A bonding screw is unneeded in a subpanel.

    Name the methods of sizing bonding jumpers outlined in NEC Section 250-28D.

    1. Bonding jumper is sized not less than 12.5% of the largest phase conductor.

    2. Based on the largest ungrounded service conductor.

    3. Based on the largest sum of the service conductors.

    NEC Table _____ covers grounding electrode conductor sizing.

    NEC Table 250.66

    Which NEC reference identifies wire sizing and the temperature a wire can handle in amps?

    NEC Tables Annex C1 and C2 identify both wire sizing and the temperature a wire can handle in amps.

    Define a grounding system according to NEC.

    A gounding system is connected to the ground or to a conductive body that extends the ground connection.

    What is the topic of NEC Section 250-122?

    Is dedicated to the sizes of the grounding conductor

    What is the NEC definition of a circuit breaker?

    A device designed to trip when an overcurrent is detected.

    NEC Section 300-13 provides information on?

    Mechanical and Electrical continuity conductors.

    What is the subject of NEC Section 250-2D?

    Bonding jumpers

    ______ are the subject of NEC Section 680-20.

    Electrical installations at permanently installed pools.

    Which NEC Section covers equipment grounding conductors.

    NEC Section 250-118

    Which NEC sections covers identification of equipment grounding conductors?

    NEC Section 250-119 1-14

    Which NEC Section covers ground terminal identification.

    NEC Section 250-126

    Bonding is the establishment of ______ connection between metal parts.


    NEC Section 250-134 provides information on what topic?

    Equipment fastened or connection between metal parts.

    Equipment grounding conductor _____ is (are) discussed in NEC Section 250-130.


    NEC Section 250-118 states that a grounded conduct must run _____ flexible conduit.


    NEC Section _____ oversees bonding of flexible type conduit.

    NEC Section 250.118(5)

    Which NEC article covers cable trays?

    NEC Article 392

    What is the proper procedure for bonding a motor conduit with metal flex?

    A bonding jumper should be installed inside or outside raceway within 6ft. of attachment. (NEC 250.118)

    Threaded pipe can be used for bonding purposes? (True or False)

    True (NEC 250.92B)

    Shoulder fittings with locknuts are allowable as bonding devices? (True or False)

    True (NEC 250.92B)

    What kind of information does NEC Section 250-66 cover?

    Covers the sizes of alternating current grounding electrode conductors.

    NEC Section 250-102 is devoted to equipment _____.

    Equipment Bonding Jumpers

    Give guidelines for using sheet metal screws as bonding agents.

    Electricians can use sheet metal screws for bonding when those screws are green and have hexagonal heads (NEC 250.8), but it is generally considered unwise.

    Which NEC article covers service drops?

    NEC Article 230

    According to NEC, trees are approved service conductors. (True or False)

    False, NEC does not approve tress as service conductors.

    When a service entrance wire is under at least 2 in. of concrete, a disconnect is required between meter base and panel. (True or False)

    False, No disconnect is required.

    Above sidewalks accessible by pedestrians, a service drop not over 600V must be at least _____ft. high.


    What is the service drop distance, in feet, of a 200-amp service crossing residential property?


    The required clearance for a 400-amp service drop across a major roadway is?


    Describe the information covered in NEC Article 230.9 (A)

    Covers clearances on buildings.

    According to NEC 230.9(A), an unsheathed service conductor must be _____ft. from a window that opens.


    Which NEC Article covers grounding?

    NEC Article 250

    System and circuit grounding involves taking alternating current to ground? (True or False)


    The process of equipment _____ exposes current-carrying parts to a grounding system.


    Small power tools are protected in what two ways?

    1.Insulated Housings.
    2. Ground prong on plugs.

    When bonding a plumbing system to the electrical system, it is not necessary to jump the water meter as this connection is built into the meter. (True or False)

    False, run ground wire from panel to copper water pipe then jump the water meter using grounding clamps.

    Explain the proper way to ground a subpanel in the same building.

    To ground a subpanel in the same building, run a four-wire system from main panel to subpanel.

    Discuss the proper way to ground a subpanel in another building.

    To ground a subpanel in the another building, run bare copper wire from subpanel to ground rod inside or outside.

    Something that is ______ is connected to ground or to a conductive body that extends the grounding connection.


    Describe a grounding conductor.

    A grounded conductor is a system or circuit that is intentionally grounded.

    Define the term grounding conductor.

    A grounding conductor is a conductor or circuit of a wiring system to a grounding electrode (ground rod).

    A(n) _____ is the fundamental particle of electricity.


    Voltage can be fatal to a person. (True or False)

    False, Current is fatal to people not Voltage

    What determines the severity of an electrical shock?

    Voltage level, amount of protective clothing, and moisture on skin or outerwear all impact a ground connection.

    Grounding reduces the voltage that might cause a fatal electrical shock by allowing excess current to flow to the ground. (True or False)


    _____ and ______ are two types of electrical faults.

    Ground and Arc are two types of electrical faults.

    On a 400-amp services, how many ground rods are required?

    2 ground rods 6 ft apart.

    The standard length for IMC is?

    Two outside ground wire are needed on a 400 amp.

    NEC allows electricians to ground gas pipes to existing, grounded water pipes. (True or False)

    True, when those water pipes are grounded.

    When is building steel permitted in an electro grounding system?

    When only the steel is connected to earth ground.

    _____ determines what size ground wire used on a service.

    The size of the largest conductor determines what size ground wire used on a service.

    A grounding conductor is what color?

    A grounding conductor is green.

    What is meant by the term isolated grounded reciprocal?

    An isolated grounded reciprocal is a separate ground from a device directly to a panel.

    Explain the process of cad welding?

    Exothermic welding involves the fusion of metal materials or copper to rebar.

    Electricians may use rebar as a grounding means. (True or False)

    True, Electricians may use rebar as a grounding means.

    Electricians must use a(n) _____ to properly connect number 4 copper to a ground rod.

    A Direct burial clamp is needed to properly connect number 4 copper to a ground rod.

    Using NEC Section 250-8, identify five methods of making connections.

    1. ed Pressures Connectors
    2. Terminal Bars
    3. Pressure Connectors ed As Ground and Bonding Equipment
    4. Exothermic Welding
    5. Machine screw-type fasteners that engage not less than two threads or are screwed with nuts

    Underground service is simpler to troubleshoot and repair than overhead service? (True or False)

    Relative to underground service, overhead electrical service is simpler to troubleshoot and repair and is the easier option when running electricity across roadways, waterways, and right-of-ways.

    In NEC, Table _____ provides the sizing of grounding electrode conductors.

    NEC 250.66 provides the sizing of grounding electrode conductors

    Describe the process for bonding three 200-amp disconnects to make a proper grounding system.

    To make a proper grounding system using three 200-amp disconnects, use a ground wire of sufficient size to go from panel to panel with a lug, screw, or ground bar, if provided.

    In terms of AWG, what is the minimum grounding conductor size permitted?

    The smallest grounding conductor permitted is 6 awg or larger.

    The way to ground a transformer in a commercial building is to place a grounding rod inside the building? (True or False)

    False, The way to ground a transformer in a commercial building is to place a grounding rod outside or beneath the building.

    Why do stoves require a four-wire system?

    Two hots are needed to operate the stove neutral. The timers and clocks can serve as ground for tripping mechanism.

    Why do dryers require a four-wire system?

    Two hots are needed to operate the heater neutral. The timers can serve as ground for tripping mechanism.

    Air-conditioning units, hot water heaters, and baseboard heat require a four-wire system? (True or False)

    False, a A/C unit needs only 220 and a ground to complete the circuit.

    Which of the following NEC sections outlines which air-conditioning systems requires no grounding?

    NEC 250.114

    Explain where and why isolated systems are used.

    Isolated systems are used in healthcare facilities due to explosive gases.

    Electricians should put grounded conductors on yellow reciprocal screws? (True or False)

    False, grounding conuctors belong on the green screws.

    On a 200-amp service, the electrician should use _____ or _____ size grounded conductor in the service cable.

    2/0 or 4/0

    When using 500 MCM, _____ or ______ size ground wire is appropriate on a 400-amp service.

    350MCM or 400MCM

    Name a common application for high impedance grounding.

    High impedance grounding is used for grounding radio towers. NEC 250.20(E)

    What is the proper way to test conduit for proper grounding?

    To test conduit for proper grounding, check ohms or use 120V receptacle and touch to ground to check for voltage.

    How does an NEC violation affect the occupancy of an existing installation?

    Per NEC 90.4, 510.2, and various local codes, occupancy is permitted in the event of a code violation as long as the occupancy remains unchanged and no hazardous condition exists.

    The maximum operating temperature of type FFH-2 fixture wiring is?

    Per NEC 402.3, FFH-2 fixture wiring is useable up to 75 degrees C

    NEC Article _____ addresses bonding requirements in healthcare facilities.

    NEC Article 517

    FMT conductors are appropriate for battery storage areas. (True or False)

    False, Per 360.12, FMT is disallowed from battery storage areas

    A circuit that cannont cause a fire in a hazardous condition is called a(n) _____ system.

    An Intrinsically Safe System.

    When local ordinance superseded or administers NEC, NEC uses what phrase?

    "Authority Having Jurisdiction (AHJ)"

    A(n) _____ circuit is designed and created for one load.


    NEC Chapter _____ specifies conduit fill requirements for fiber-optic cabling.

    Chapter 9

    Which NEC chapter discusses fixture wiring and fixture wires.

    Chapter 3

    NEC 90.1(A) states that the purpose of NEC is the "practical safeguarding of _____ from hazards arising from the use of electricity".

    people and property

    NEC Article 426 recognizes which three kinds of heating systems?

    Resistive, impedance, and skin effect.

    What is proper phase arrangement when wiring a three-phase panelboard?

    Per NEC 450.3, phases must arrange in a particular order: A, B, C, from left to right or from top to bottom as seen from the front.

    When installing an autotransformer, it is important to remember to insert an OCPD in series with the shunt winding. (True or False)

    False, Per NEC 450.4 a OCPD is no needed.

    Which NEC guidelines guarantee the best workmanship and safest installations possible.

    NEC 90.1(C)

    When NEC Article 100 describes "Feeder" as.

    "All circuit conductors between the service equipment, the source of a separately derived system, or other power source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device,"

    NEC Article _____ outlines the restrictions for using plastic junction or device boxes.

    NEC 314.3

    NEC Chapters 1-4 governs basic practices in effect in hazardous areas, except as modified by specific requirements outlined in NEC Chapter _____.

    Chapter 5

    Name two hazards found in a Class III hazardous environments.

    1. Air-borne Particulate
    2. Sawdust

    General-purpose enclosures are NEC approved for intrinsically safe apparatuses. (True or False)

    True, Intrinsically safe areas are safe with out enclosure, but enclosure are required for other protections.

    Fusing the load side of a transformer sufficiently protects the transformer. (True or False)

    False, Fuses on the load side do not protect the transformer.

    Per NEC 450.3, when a transformer is enclosed, install _____ fuses at the transformer's primary.


    The NEC defines ampacity as,

    "the current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating"

    Where does NEC the types of insulation material deemed acceptable in wet locations?

    NEC 310.8

    Leads to an unused current transformer should be.

    NEC 110.23 states that, "Unused current transformers associated with potentially energized circuits shall be short circuited."

    In what sections does NEC outline the requirements for appliance calculations?

    NEC 220.16 - 220.20 cover appliance calculations.

    Typically, transformers are available in one of two types: _____ and _____.

    Liquid Filled and Dry Versions

    NEC Chapter 9, Table 5, states,

    To locate wire type and size to be installed. Repeat for each conductor, keeping a running total. Derate by 40% to ge the total raceway area.

    NEC Chapter 9, Table 4, states,

    For a raceway to be used. Find a value for area larger than the raceway area calculated previously.

    The "3-ft. rule" for clearances around things like control panels is adequate. (True or False)

    False, Depending on the location and environment, 3ft. may be insufficient clearance. While grouping apparatuses tightly may save space, repair and maneuvering options are limited should a device fail.

    When establishing ground clearance in new construction. It is best to make the ground clearance slightly more than the NEC-stated requirement to provide a margin for error. (True or False)

    True, It is a good idea to exceed the requirements by a foot or two.

    What Section discusses "clearance(s) from ground.

    NEC 225.18

    Service drops must be installed so as to be "readily accessible." (True or False)

    False, Per NEC 230.24, Service drop connectors shall not be readily accessible.

    Extension cords are acceptable in wet areas. (True or False)

    True, Per NEC Article 400, only when rated for wet areas.

    The requirements for liquid-filled transformers are the same regardless of the liquid used in the transformer. (True or False)

    False, Per NEC 450.23-26 liquid-filled transformers have different requirements based on the dielectric fluid.

    NEC Article 526 helps electricians determine requirements for _____.

    Deicing systems

    Disconnects and switches used with appliances must indicate, on their switches, the on- and off-positions. (True or False)

    True, Per NEC 422.35

    In a three-phase delta system, the leg with the highest voltage must be _____.

    Identified as the "B" leg

    Branch circuits must be loaded equally in terms of wattage per unit area. (True or False)

    True, Per NEC 210.11

    An electrician can safely recess a panel board into a flammable wall. (True or False)

    False, NEC 312.3, disallows recessing panels in flammable walls.

    All metallic boxes and components must be grounded unless a grounding conductor is absent. (True or False)

    False, NEC 314.4, requires all metallic boxes to be grounded.

    Nameplates that rate protective devices describe which of the following?

    Per NEC 422.11, The size of the breaker to use.

    NEC maintains no ampacity requirements for fixture wiring because all fixtures undergo the UL approval process. (True or False)

    False, NEC 402.5 defines ampacity requirements for fixture wires.

    The calculations for protecting motor circuits are the same as those for non motor circuits. (True or False)

    False, Protecting a motor and a motor circuit are two very different things

    Per NEC Article 410, luminaires may mount on drop-ceiling tiles. (True or False)

    False, ceiling tiles are never appropriate device support.

    The requirements for burying 240V conductors are found in NEC _____.

    NEC 300.5, provides requirements up to 600V

    NEC _____ outlines the requirements fo AC type (armored) cable.

    NEC 320

    A garage door opener is considered an appliance for NEC purpose. (True or False)

    True, Per NEC 422.31

    Appliances with motors over 0.125 hp must have a separate means of disconnect. (True or False)

    True, Per NEC 422.31

    When running new work over old, hanging a second support from a primary support is acceptable practice. (True or False)

    True, Per NEC 300.11 hanging a second support when running new over old is acceptable and a common practice.

    Installation of a floor drain in a vault intended for wet transformer(s) is ______.

    Per NEC 450.46 only transformers over 100KW require a drain, however installing a drain in case of dielectric spills is good practice.

    A TVSS provides adequate protection against lighting strikes. (True or False)

    False, a TVSS is only for protecting against predictable anomalies, and short-duration spikes of high-voltage.

    It is possible to violate the NEC by tightening a bolt or fastener too tight. (True or False)

    True, all equipment must be installed per manufacturer's instructions and specifications, The apparatus is void and violates NEC if this is not done.

    When installing a cable tray, only the sections nearest the terminations must be grounded. (True or False)

    Per NEC 392.7(B) Bonding of all cable tray sections is required.

    Using aluminum wire with receptacles must be _____.

    Marked CO/ALR

    How would demand be calculated in a commercial environment in which a branch circuit could effectively handle 20 KW?

    Per NEC 220.13, use 100% of the first 10KW and 50% of the demand above 10KW. In this case, the demand factor would be 10,000 plus half the remaining 10,000 or 15,000W

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