Texas Journeyman Electrician Exam: all 731 questions with answers

Each question leads to its own page with the answers and the solution.

• Definitions, Theory and Plans108 questions
• Services and Service Equipment48 questions
• Feeders and Overcurrent Protection48 questions
• Branch Circuits, GFCI and AFCI71 questions
• Grounding and Bonding60 questions
• Wiring Methods, Conductors and Boxes52 questions
• Equipment, Devices and Luminaires39 questions
• Motors, HVAC, Generators and Transformers61 questions
• Special Occupancies26 questions
• Special Equipment, Pools, PV and EV48 questions
• Emergency, Limited Energy and Communications18 questions
• Load Calculations32 questions
• Electrical Calculations120 questions

Definitions, Theory and Plans

• 1001If the resistance of a circuit stays the same and the applied voltage is increased, what happens to the current?
• 1002A heater operates on a fixed supply voltage. If its element resistance were doubled, the current would:
• 1003If the current through a fixed resistance is doubled, the power dissipated in that resistance becomes:
• 1004A resistive load draws 10 amperes from a 120-volt supply. How much power does it use?
• 1005Which unit is used to express electrical resistance?
• 1006In a series circuit, which quantity is the same at every component?
• 1007Three resistors of 10, 20 and 30 ohms are connected in series. What is the total resistance?
• 1008In a parallel circuit, which quantity is the same across every branch?
• 1009Two 10-ohm resistors are connected in parallel. What is the combined resistance?
• 1010When another branch is added to a parallel circuit, the total resistance of the circuit:
• 1011Several lamps are wired in series. If one lamp filament opens, what happens to the others?
• 1012Kirchhoff's current law states that at any junction in a circuit:
• 1013Kirchhoff's voltage law states that around any closed loop:
• 1014Four 1.5-volt cells are connected in series. What is the output voltage?
• 1015Identical batteries connected in parallel will:
• 1016One horsepower is equal to approximately:
• 1017What does a kilowatt-hour measure?
• 1018The efficiency of a motor is found by:
• 1019How does the resistance of a conductor change if its length is doubled and the size stays the same?
• 1020For copper conductors, how does resistance normally change as conductor temperature rises?
• 1021A circular mil is defined as the area of a circle with a diameter of:
• 1022Compared with a copper conductor of the same size and length, an aluminum conductor has:
• 1023Which of the following metals is the best electrical conductor?
• 1024In an AC circuit, the tendency of current to concentrate near the outer surface of a conductor is called:
• 1025To reduce voltage drop on a long branch circuit without changing the load, an electrician can:
• 1026A material that offers very high resistance to current flow, such as glass or rubber, is called:
• 1027In the United States, the standard frequency of the utility supply is:
• 1028The RMS (effective) value of an AC voltage is the value that:
• 1029A 120-volt RMS sine wave has a peak voltage of approximately:
• 1030Power factor in an AC circuit is the ratio of:
• 1031In a purely resistive AC circuit, such as an incandescent lamp, the power factor is:
• 1032In a circuit that is mainly inductive, such as a motor winding, the current:
• 1033In a circuit that is mainly capacitive, the current:
• 1034A plant with many induction motors has a low lagging power factor. What is commonly added to improve it?
• 1035As the supply frequency increases, the inductive reactance of a coil:
• 1036As the supply frequency increases, the capacitive reactance of a capacitor:
• 1037The total opposition to current flow in an AC circuit, combining resistance and reactance, is called:
• 1038A series AC circuit has 3 ohms of resistance and 4 ohms of inductive reactance. What is the impedance?
• 1039The unit of inductance is the:
• 1040Once fully charged in a steady DC circuit, a capacitor:
• 1041Capacitors connected in parallel have a total capacitance that is:
• 1042A series RLC circuit is at resonance when:
• 1043Volt-amperes (VA) in an AC circuit represent:
• 1044In a three-phase system, the three voltages are displaced from each other by:
• 1045In a wye-connected system, the line-to-line voltage equals the line-to-neutral voltage multiplied by:
• 1046On a 208Y/120-volt three-phase, four-wire system, what voltage is measured from any phase conductor to the neutral?
• 1047On a 480Y/277-volt system, what is the voltage between any two phase conductors?
• 1048In a delta-connected transformer winding, the line current equals the phase (winding) current multiplied by:
• 1049On a 240/120-volt three-phase, four-wire delta system with a center-tapped winding, the high leg measures approximately how many volts to the neutral?
• 1050On a balanced three-phase, four-wire wye system serving only linear resistive loads, the neutral current is:
• 1051On a wye system serving many computers and LED drivers, which harmonics add together in the neutral instead of canceling?
• 1052Which expression gives the true power of a balanced three-phase load?
• 1053How is the rotation of a three-phase induction motor reversed?
• 1054What is the synchronous speed of a 4-pole induction motor on a 60 Hz supply?
• 1055The difference between the synchronous speed of the rotating field and the actual rotor speed of an induction motor is called:
• 1056A transformer has 1,000 turns on the primary and 100 turns on the secondary. If 480 volts is applied to the primary, the secondary voltage is:
• 1057In an ideal step-down transformer, compared with the primary side, the secondary side has:
• 1058Why will a transformer not operate on steady direct current?
• 1059Transformer cores are made of thin laminated steel sheets mainly to reduce:
• 1060Transformers are rated in kVA rather than kW because:
• 1061A transformer that uses a single winding for both primary and secondary, with no electrical isolation between them, is:
• 1062Two magnets are placed with their north poles facing each other. They will:
• 1063Current flowing through a conductor creates:
• 1064A voltage is induced in a conductor when it moves through a magnetic field and cuts the lines of flux. This principle is called:
• 1065Lenz's law states that an induced current flows in a direction that:
• 1066Which material is best suited for the core of an electromagnet because it magnetizes easily and has high permeability?
• 1067A generator converts:
• 1068A diode is a semiconductor device that:
• 1069An insulation resistance tester (megohmmeter or megger) checks insulation by:
• 1070An electrician places a clamp-on ammeter around both the hot and neutral conductors of a single-phase, two-wire circuit carrying a load. The meter will read:
• 1071How must a voltmeter be connected to measure the voltage across a load?
• 1072Why must an ohmmeter be used only on a de-energized circuit?
• 1073Which instrument directly measures true power in watts?
• 1074A floor plan is drawn at a scale of 1/4 inch = 1 foot. A conduit run measures 6 inches on the drawing. How long is the actual run?
• 1075On an electrical floor plan, a small circle with two short parallel lines through it typically represents:
• 1076On an electrical plan, the letter S with a small subscript 3 next to it indicates:
• 1077On a branch circuit layout, a line ending in an arrowhead with a circuit number beside it means:
• 1078On a lighting plan, a curved dashed line drawn from a switch to a luminaire shows:
• 1079A diagram that uses a single line to represent a three-phase circuit and shows the service, feeders, transformers and panels is called:
• 1080A panel schedule on a set of electrical drawings normally lists:
• 1081The abbreviation WP next to a receptacle symbol on a plan usually means the receptacle must be:
• 1082Under the NEC definition, equipment is readily accessible when it can be reached for operation or inspection:
• 1083As defined in the NEC, a continuous load is one where the maximum current is expected to continue for:
• 1084Which set of features makes a space a dwelling unit under the NEC?
• 1085According to the NEC, a qualified person is someone who:
• 1088The circuit conductors between the final overcurrent device protecting the circuit and the outlets are called:
• 1089Conductors running from the service equipment to a subpanel that contains the final branch-circuit breakers are classified as:
• 1090Ampacity is defined in the NEC as the maximum current a conductor can carry continuously:
• 1091In the NEC, the term approved means:
• 1092Equipment that has a label, symbol or identifying mark of an organization acceptable to the AHJ that maintains periodic inspection of its production is described as:
• 1093Under the NEC, operation of equipment in excess of its normal full-load rating that would cause damaging overheating if it persisted is called:
• 1094Under the NEC, a disconnect is considered in sight from the equipment it serves when it is visible and not more than:
• 1095A branch circuit with two or more ungrounded conductors having a voltage between them and a grounded conductor with equal voltage to each ungrounded conductor is a:
• 1096A building-supplied transformer whose secondary has no direct electrical connection to the supply conductors, except through grounding and bonding connections, creates:
• 1097The point of connection between the facilities of the serving utility and the premises wiring is called the:
• 1098A partially protected location under a canopy or a roofed open porch is classified in the NEC as a:
• 1103NEC 110.3(B) requires that listed or labeled equipment be installed and used:
• 1104Unless the equipment is listed and marked otherwise, terminations for circuits rated 100 amperes or less (or 14 AWG through 1 AWG conductors) are based on which conductor temperature rating?
• 1105For circuits rated over 100 amperes, or conductors larger than 1 AWG, terminations are generally based on which conductor temperature column?
• 1106Copper and aluminum conductors may be joined in the same terminal or splicing connector only when:
• 1108The required depth of working space in front of a 120/240-volt panelboard (150 volts or less to ground) is, for all conditions:
• 1109A 480Y/277-volt panelboard has exposed live parts on one side of the working space and a grounded concrete wall on the other (Condition 2). What is the minimum depth of working space?
• 1110Equipment at 277 volts to ground has exposed live parts on both sides of the working space (Condition 3). The minimum working space depth is:
• 1111What is the minimum width of the working space in front of electrical equipment covered by 110.26(A)?
• 1112For service equipment and panelboards, the minimum headroom of the working space is generally:
• 1113A homeowner stacks storage boxes in the working space in front of a panelboard. Under 110.26, this is:
• 1115NEC 110.12 requires electrical equipment to be installed:
• 1116Equipment intended to interrupt current at fault levels must have an interrupting rating that is:

Services and Service Equipment

• 2002What is the maximum number of service disconnects permitted for one service?
• 2004A 120/240 volt service drop passes over a roof with a slope of 4 in 12. What is the minimum clearance above the roof permitted by the exception for sloped roofs?
• 2005Overhead service conductors cross a public street that is subject to truck traffic. What is the minimum vertical clearance above the street?
• 2006Overhead service conductors run beside a window that is designed to be opened. What minimum horizontal clearance from the window is required?
• 2007Since the 2020 edition, what is required for all services supplying dwelling units?
• 2008Which statement about overhead service conductors and building openings is correct?
• 2010Under the 2023 and 2026 NEC, a one-family dwelling is supplied by a feeder from a service on a pole. What is required for this dwelling?
• 2012In general, how many services may supply a single building or structure?
• 2014What is the minimum size copper conductor permitted for an overhead service drop, other than for limited loads?
• 2016Where must a service head generally be located in relation to the point of attachment of the service drop?
• 2017What is the minimum width of the working space in front of service equipment?
• 2018Which of the following may not be used to support overhead conductor spans?
• 2019Which types of surge protective device satisfy the dwelling unit service surge protection rule?
• 2020Service-entrance cable run on the outside of a building must be supported within 12 in. of the service head and at intervals not exceeding what distance?
• 2021A commercial service supplies 120 A of continuous load and 40 A of noncontinuous load. What is the minimum ampacity of the service-entrance conductors?
• 2022Under the 2020 and later editions, how must two to six service disconnects for one service be arranged?
• 2023A service supplies a small commercial building, not a dwelling, with more than two branch circuits. What is the minimum service disconnect rating?
• 2024What is the minimum rating of the service disconnecting means for a one-family dwelling?
• 2026What is the minimum size aluminum conductor permitted for an underground service lateral serving a general load?
• 2027An overhead outside branch circuit spans 60 ft between supports. What is the minimum copper conductor size?
• 2028What is the minimum vertical clearance for overhead service conductors above a residential driveway when the voltage does not exceed 300 volts to ground?
• 2029Where must the service overcurrent device be located relative to the service disconnect?
• 2030What is the maximum ground-fault trip setting permitted for service GFPE?
• 2033What may be attached to a service mast that supports a service drop?
• 2034Service drop conductors at 120/240 volts pass over only the overhang of a roof to terminate at a through-the-roof service mast. What is the minimum clearance above the overhang?
• 2036What must be done with a service GFPE system when it is first installed?
• 2037What is the minimum height of working space for service equipment rated 1000 volts or less?
• 2038Under the 2023 and 2026 NEC, surge protection at the service is required for dwelling units and also for which of the following?
• 2039Service conductors installed under a building are considered outside the building when they are covered by at least how much concrete?
• 2040How must each service disconnect be identified?
• 2041A detached building is supplied by one feeder. Where must its building disconnecting means be located?
• 2042Where may the service disconnecting means for a commercial building be installed?
• 2044A 480Y/277 volt switchboard faces a concrete wall (Condition 2). What is the minimum depth of the working space?
• 2045Overhead service conductors operating at more than 300 volts to ground pass over a residential driveway. What is the minimum vertical clearance?
• 2047Which of the following is permitted to be connected on the supply side of the service disconnecting means?
• 2048Which situation permits an additional service to a building?
• 2050A service drop cable with a bare messenger operates at 120/240 volts. What is the minimum clearance above a sidewalk accessible only to pedestrians?
• 2051At a supply voltage of 1000 volts or less, additional services are permitted for capacity reasons when the load exceeds what value?
• 2052A service disconnect supplies only two 2-wire branch circuits. What is its minimum rating?
• 2053What is the minimum depth of working space in front of a 120/240 volt panelboard with live parts on one side and no grounded parts on the other (Condition 1)?
• 2054Under the 2026 NEC, where must the service disconnecting means for a one-family dwelling be located?
• 2055Under the 2026 NEC, what happened to section 230.85 Emergency Disconnects?
• 2056How is the overcurrent protection for each ungrounded service conductor generally sized?
• 2057What is the maximum number of disconnects permitted for a building supplied by one outside feeder?
• 2058What is the minimum height above finished grade for the point of attachment of a service drop to a building?
• 2059Ground-fault protection of equipment is required for a service disconnect rated 1200 A on which system?
• 2061Overhead feeder conductors run from a house to a detached garage at 120/240 volts. What is the minimum clearance above the residential driveway?
• 2062May branch circuit conductors be installed in the same raceway as service-entrance conductors?

Feeders and Overcurrent Protection

• 3001Which location is prohibited for an OCPD in all three editions?
• 3002When the handle of a circuit breaker is operated vertically, what position must be the on position?
• 3003In the 2026 NEC, what term is used throughout the code in place of the full phrase overcurrent protective device?
• 3004A series combination rating may not be used when motors connected between the two devices contribute more than what percentage of the lower-rated breaker's interrupting rating?
• 3005When may a feeder OCPD be sized at 100 percent of the continuous load?
• 3006In which case is the next size up rule not permitted?
• 3007The available fault current at a panelboard is 18,000 A. Which breaker interrupting rating is acceptable?
• 3008What is the maximum rating of a plug fuse?
• 3009A feeder is protected at 400 A. What is the minimum copper THWN tap conductor at 75 degrees C for a 25 ft tap?
• 3010What is the maximum height of the center of the operating handle of a circuit breaker in its highest position?
• 3011A 400 A feeder OCPD protects a feeder. Field-installed 10 ft tap conductors leave the enclosure. What is the minimum tap ampacity?
• 3012In other than dwelling units, service equipment must be field marked with what information?
• 3013How long must a load run to be considered a continuous load?
• 3014Which of the following is not a standard ampere rating for an inverse time circuit breaker?
• 3015Under the 25 ft feeder tap rule, what minimum ampacity must the tap conductors have?
• 3016In a dwelling unit, in which location are OCPDs prohibited?
• 3017Which situation is an exception to the small conductor rule?
• 3018Transformer secondary conductors not over 25 ft long must have an ampacity of at least what value?
• 3019What must the interrupting rating of a circuit breaker be at least equal to?
• 3020Why may an OCPD panelboard not be installed in a clothes closet?
• 3021What is the maximum OCPD rating for which the next size up rule may be used?
• 3022A feeder supplies 100 A of continuous load and 30 A of noncontinuous load. What is the minimum feeder conductor ampacity before any adjustment?
• 3023What is the role of a supplementary overcurrent protective device?
• 3024Unless specifically permitted elsewhere, what is the maximum OCPD for 12 AWG copper conductors?
• 3025A feeder conductor has an ampacity of 115 A and does not supply receptacles for portable loads. What is the largest standard OCPD permitted under the next size up rule?
• 3026GFPE is required for a feeder disconnect rated 1000 A or more on which system?
• 3027Unless specifically permitted elsewhere, what is the maximum OCPD for 14 AWG copper conductors?
• 3028Three parallel sets of conductors give a total ampacity of 1140 A. What is the largest standard OCPD permitted?
• 3029Which standard OCPD rating comes directly after 800 A?
• 3030A circuit breaker has an interrupting rating other than what value must be marked with that rating?
• 3031When is a 1200 A feeder disconnect on a 480Y/277 volt system not required to have its own GFPE?
• 3032What is the length limit for outside feeder tap conductors that terminate at a single OCPD that is part of or next to the building disconnect?
• 3033Under the 10 ft feeder tap rule, field-installed tap conductors that leave the enclosure must have an ampacity of at least what fraction of the feeder OCPD rating?
• 3035A feeder supplies a continuous load of 160 A only. What is the minimum rating of the feeder OCPD, assuming standard equipment not rated for 100 percent operation?
• 3036In a multi-tenant building, who must have ready access to the OCPDs protecting the conductors supplying a tenant space?
• 3037Arc energy reduction is required where the highest continuous current trip setting of a circuit breaker is at least what value?
• 3039May an OCPD be placed in a grounded conductor?
• 3040Which statement about supplementary OCPDs is correct?
• 3041Unless specifically permitted elsewhere, what is the maximum OCPD for 10 AWG aluminum conductors?
• 3042How must a 25 ft feeder tap terminate?
• 3043What is the general rule for the location of OCPDs?
• 3044A building main disconnect, not the service disconnect, is rated 1200 A on a 480Y/277 volt system. What does the NEC require?
• 3045A 120/240 volt slash rated circuit breaker may be used on which system?
• 3046Where a premises has feeders supplied from more than one nominal voltage system, how must the ungrounded feeder conductors be identified?
• 3047Which value is an additional standard ampere rating for fuses only?
• 3048What does selective coordination of OCPDs achieve?
• 3050Which of the following is a standard ampere rating for fuses and inverse time circuit breakers?
• 3051A circuit breaker used to switch 120 volt fluorescent lighting on a regular basis must be marked with which designation?

Branch Circuits, GFCI and AFCI

• 4001In a dwelling unit, GFCI protection is required for all 125-volt through 250-volt receptacles installed in which of the following locations?
• 4002A receptacle in a dwelling unit bedroom is installed 5 ft from the top inside edge of the bowl of a bar sink. Is GFCI protection required?
• 4003In a dwelling unit, receptacles within what distance of the outside edge of a bathtub or shower stall require GFCI protection?
• 4009A dwelling has a fully finished basement used as a recreation room. Do the 125-volt receptacles in this finished basement require GFCI protection?
• 4010A single 125-volt receptacle in an attached dwelling garage is dedicated to a chest freezer. Is GFCI protection required?
• 4013Where must a GFCI device that provides the protection required by 210.8 be located?
• 4014When applying the 6 ft sink and bathtub distances in 210.8, how is the distance to a receptacle measured?
• 4015A dwelling has an indoor area that is a damp location, such as a covered utility room open to weather. Do 125-volt receptacles there require GFCI protection?
• 4017In a restaurant kitchen, which 125-volt, 20-ampere receptacles require GFCI protection?
• 4018A 125-volt receptacle is installed on the roof of an office building for servicing a rooftop unit. What protection is required?
• 4019In a fitness center, which of the following areas requires GFCI protection for its 125-volt receptacles under 210.8(B)?
• 4022In a commercial building, which of the following areas is excluded from the garage and service bay GFCI requirement in 210.8(B)?
• 4023A receptacle in a commercial building is located in an unfinished basement area used for storage. Is GFCI protection required?
• 4024A 125-volt receptacle in an office break room is 4 ft from the break room sink. Is GFCI protection required?
• 4038In a dwelling unit, which of the following locations requires AFCI protection for 120-volt, 15- and 20-ampere branch circuits supplying outlets?
• 4040Which of the following dwelling unit circuits requires AFCI protection?
• 4042In a hotel, 120-volt, 15- and 20-ampere branch circuits supplying outlets in guest rooms and guest suites require which protection?
• 4047Which AFCI device installed at the origin of a branch circuit provides protection of the entire branch circuit?
• 4049What is the minimum number of 20-ampere small-appliance branch circuits required for receptacle outlets in a dwelling kitchen, pantry, breakfast room and dining room?
• 4050Which of the following is permitted to be supplied by a dwelling small-appliance branch circuit?
• 4051How may the receptacle outlet for a dwelling kitchen refrigerator be supplied?
• 4052What branch circuit is required in a dwelling unit to supply the laundry receptacle outlets?
• 4053A single 20-ampere branch circuit supplies receptacle outlets in all three bathrooms of a house. What else may this circuit supply?
• 4054A 20-ampere branch circuit supplies only one bathroom of a dwelling. Which of the following may it also supply?
• 4055Since the 2020 NEC, an attached dwelling garage must have at least one branch circuit for its receptacle outlets. What is the required rating of this circuit?
• 4056The required 20-ampere garage receptacle branch circuit in a dwelling is permitted to also supply which of the following?
• 4057In a dwelling living room, receptacles must be installed so that no point measured horizontally along the floor line of any wall space is more than what distance from a receptacle?
• 4058In a dwelling bedroom, what is the minimum width of a wall space that must be counted for receptacle placement under 210.52(A)?
• 4059Along a dwelling kitchen wall countertop, receptacles must be installed so that no point along the wall line is more than what distance from a receptacle outlet?
• 4060In a dwelling kitchen, a wall countertop space of what minimum width requires a receptacle outlet?
• 4061Receptacles installed on the wall above a dwelling kitchen countertop must be located not more than what distance above the countertop?
• 4069A dwelling unit hallway must have at least one receptacle outlet when the hallway is at least how long?
• 4070For a one-family dwelling, how many outdoor receptacle outlets are required at grade level as a minimum?
• 4071A dwelling has a deck accessible from inside the dwelling. What is the maximum height of the required receptacle outlet above the deck walking surface?
• 4072A one-family dwelling basement has a finished area and two separate unfinished storage areas. How many receptacles are required in the unfinished areas as a minimum?
• 4073In a dwelling unit attached garage, at least one receptacle outlet is required in each vehicle bay at what maximum height above the floor?
• 4074In a dwelling bathroom, at least one receptacle outlet must be installed within what distance of the outside edge of each basin?
• 4075A dwelling foyer that is not part of a hallway requires a receptacle on each wall space 3 ft or more wide when the foyer area is greater than what size?
• 4076A receptacle in a dwelling living room is installed 6 ft above the floor. Does it count toward the required wall space receptacles?
• 4077A floor receptacle in a dwelling family room may count as the required receptacle for a wall space if it is located within what distance of the wall?
• 4078How many receptacle outlets in a hotel guest room must be readily accessible when the remaining receptacles are located for convenient furniture placement?
• 4079A hotel guest suite includes permanent provisions for cooking. Which receptacle rules apply to the suite?
• 4080A 20-ampere branch circuit supplies two or more receptacles. Which receptacle ratings are permitted?
• 4081A single receptacle is installed on an individual 20-ampere branch circuit. What is the minimum rating of the receptacle?
• 4082What is the maximum cord-and-plug load permitted on a 20-ampere receptacle supplied by a 20-ampere branch circuit with multiple outlets?
• 4084On a 20-ampere branch circuit, what is the maximum rating of a single cord-and-plug-connected utilization equipment not fastened in place?
• 4085A 20-ampere branch circuit supplies lighting units and also fastened-in-place utilization equipment. What is the maximum total rating of the fastened-in-place equipment?
• 4086Which loads are 40-ampere and 50-ampere branch circuits permitted to supply in any occupancy?
• 4087In a dwelling unit, a 30-ampere branch circuit is permitted to supply which of the following?
• 4088A branch circuit supplies a continuous load of 16 amperes and no noncontinuous load. What is the minimum conductor ampacity before any adjustment or correction?
• 4089A branch circuit supplies 24 amperes of continuous load and 6 amperes of noncontinuous load. What is the minimum standard overcurrent device rating?
• 4090For branch circuit sizing, a continuous load is one where the maximum current is expected to continue for how long?
• 4091When may a branch circuit overcurrent device be sized at 100 percent of the continuous load instead of 125 percent?
• 4094A multiwire branch circuit supplies receptacles in a dwelling. What does the NEC require at the point where the branch circuit originates?
• 4095A multiwire branch circuit in general may supply only which type of load?
• 4096How must the conductors of a multiwire branch circuit be identified in a panelboard?
• 4097In a 120/240-volt, 3-wire multiwire branch circuit, why must the two ungrounded conductors be connected to opposite lines?
• 4098In a dwelling living room, what may substitute for the required wall-switch-controlled lighting outlet?
• 4099In which dwelling rooms is a switched receptacle NOT permitted as a substitute for the required wall-switch-controlled lighting outlet?
• 4100A dwelling interior stairway has eight risers between floor levels. Where are wall switches required for the stairway lighting?
• 4101A dwelling attic contains a furnace that requires servicing. What lighting outlet is required?
• 4102For a dwelling, which of the following is NOT considered an outdoor entrance for the required exterior lighting outlet?
• 4103A 12 AWG copper THHN conductor has a 90 C ampacity of 30 amperes in Table 310.16. What is the maximum overcurrent protection generally permitted for it?
• 4104What is the ampacity of a 6 AWG copper THWN conductor in the 75 C column of Table 310.16?
• 4105A 30-ampere branch circuit terminates on equipment whose terminals are not marked with a temperature rating. Which column of Table 310.16 must be used to select the conductor?
• 4106An 8 AWG copper THHN conductor connects to terminals rated 75 C on both ends. What ampacity may be used for the circuit?
• 4107For a circuit rated over 100 amperes with conductors larger than 1 AWG, which temperature column may be used for termination purposes unless equipment is marked otherwise?
• 4108When 90 C rated THHN conductors are installed with 75 C terminations, what is the 90 C ampacity used for?
• 4109How may a 10 AWG grounded conductor be identified?
• 4110A 2 AWG grounded conductor has black insulation. How may it be identified as the grounded conductor?
• 4112A white conductor in a cable assembly is used as an ungrounded conductor for a switch loop. What does the NEC require?

Grounding and Bonding

• 5001At a building or structure, which of the permitted grounding electrodes must be bonded together to form the grounding electrode system?
• 5002A metal underground water pipe qualifies as a grounding electrode only if it is in direct contact with the earth for at least what length?
• 5003When a metal underground water pipe is used as a grounding electrode, what else does the Code require?
• 5004Under the general rule, interior metal water piping located more than what distance from its point of entrance may NOT be used to interconnect electrodes that are part of the grounding electrode system?
• 5005A concrete-encased electrode made of bare copper conductor must be at least 20 ft long and not smaller than what size?
• 5006A concrete-encased electrode must be covered by at least how much concrete?
• 5007A ground ring encircling a building must consist of at least 20 ft of bare copper conductor not smaller than
• 5008What is the minimum length of a rod or pipe grounding electrode?
• 5010Where rock bottom prevents driving a ground rod vertically, the rod may be driven at an angle not exceeding what from vertical?
• 5011A single rod electrode does not need a supplemental electrode only if its resistance to earth is
• 5012Where two ground rods are installed to meet the supplemental electrode requirement, they must be spaced at least how far apart?
• 5013A ground rod measured 40 ohms, so a second rod was driven 6 ft away. The pair still measures 30 ohms. What else is required?
• 5014Which of the following is NOT permitted to be used as a grounding electrode?
• 5015The portion of a grounding electrode conductor that is the sole connection to one or more ground rods is not required to be larger than
• 5016The portion of a GEC that is the sole connection to a concrete-encased electrode is not required to be larger than
• 5017The portion of a GEC that is the sole connection to a ground ring is not required to be larger than
• 5018A service has 2/0 AWG copper ungrounded conductors. What is the minimum copper GEC to a metal water pipe electrode?
• 5019A service has 4/0 AWG copper ungrounded conductors. What is the minimum copper GEC to the building steel electrode?
• 5020A service has 500 kcmil copper ungrounded conductors. What is the minimum copper GEC to a water pipe electrode?
• 5021A service has two parallel sets of 3/0 AWG copper (about 168 kcmil each). What is the minimum copper GEC to a water pipe electrode?
• 5022A service has three parallel sets of 400 kcmil copper per phase. What is the minimum copper GEC to building steel?
• 5023How must an 8 AWG copper grounding electrode conductor be installed?
• 5024When does a 4 AWG copper grounding electrode conductor require protection?
• 5026NEC 2026 added which method for splicing a grounding electrode conductor, in addition to irreversible compression and exothermic welding?
• 5027A ferrous metal raceway that encloses a grounding electrode conductor must be
• 5028In NEC 2026, the requirement to bond ferrous enclosures of a GEC at both ends was expressly extended to include
• 5030At the service, the main bonding jumper connects
• 5031What is the minimum size copper main bonding jumper for a service with 4/0 AWG copper ungrounded conductors?
• 5032A service has four parallel sets of 500 kcmil copper per phase (2000 kcmil total). What is the minimum copper main bonding jumper?
• 5033A subpanel in the same building is fed by a feeder from the service. How must the grounded (neutral) conductor be treated at the subpanel?
• 5034For a grounded service, the GEC connection to the grounded service conductor is permitted
• 5035What is the minimum copper equipment grounding conductor for a circuit protected by a 20 A OCPD?
• 5036What is the minimum copper equipment grounding conductor for a feeder protected by a 100 A OCPD?
• 5037What is the minimum copper equipment grounding conductor for a feeder protected by a 400 A OCPD?
• 5038A 20 A branch circuit is upsized from 12 AWG to 10 AWG copper to limit voltage drop. What is the minimum copper EGC?
• 5039A 60 A circuit is upsized from 6 AWG to 4 AWG copper for voltage drop. What is the minimum copper EGC?
• 5040A 1200 A feeder is run in four parallel raceways, each with its own copper EGC. What is the minimum EGC in each raceway?
• 5041The EGC for a motor branch circuit is sized from Table 250.122 based on
• 5042Which of the following is recognized as an equipment grounding conductor?
• 5043Listed flexible metal conduit with listed fittings may serve as the EGC only where the circuit OCPD is rated not more than
• 5045Why is the earth not permitted as the effective ground-fault current path?
• 5046A ground rod is driven at a parking lot light pole and connected to the pole. How does the Code treat this rod?
• 5047Which identification is NOT permitted for an equipment grounding conductor of 6 AWG or smaller?
• 5048An insulated conductor 4 AWG or larger may be permanently identified as an EGC at installation by
• 5049A service raceway enters an enclosure through a knockout with concentric rings left in place. Which bonding method alone is NOT acceptable?
• 5050The intersystem bonding termination must be able to connect at least how many intersystem bonding conductors?
• 5051Where is the intersystem bonding termination required?
• 5052A service has 3/0 AWG copper ungrounded conductors. What is the minimum copper bonding jumper for the interior metal water piping?
• 5053Metal gas piping that is likely to become energized may be bonded by
• 5054For a separately derived system, where is the system bonding jumper installed under the general rule?
• 5055A transformer supplies 250 kcmil copper secondary conductors. What is the minimum copper GEC for this separately derived system?
• 5056The system bonding jumper of a separately derived system is sized based on
• 5057A detached garage supplied by a feeder must have a grounding electrode system, except where it is supplied by
• 5058At a separate building supplied by a feeder that includes an EGC, the grounded conductor at the building disconnect must be
• 5059Which of these AC systems is required to be grounded?
• 5060High-impedance grounded neutral systems are permitted for 3-phase AC systems of 480 V to 1000 V where
• 5061Which of the following shall NOT be used to connect EGCs or bonding jumpers to enclosures?
• 5062An equipment bonding jumper on the load side of an OCPD is sized according to
• 5063A supply-side bonding jumper on the line side of the service disconnect is sized from
• 5065In NEC 2026, grounding and bonding requirements for systems over 1000 V were moved from Article 250 Part X to

Wiring Methods, Conductors and Boxes

• 6001What is the minimum cover for direct burial cable under the general condition (not under a building, slab, or roadway), 600 V or less?
• 6002What is the minimum cover for rigid metal conduit or IMC under the general condition, 600 V or less?
• 6003What is the minimum cover for a nonmetallic raceway listed for direct burial without concrete encasement, general condition?
• 6004A dwelling unit 120 V, 20 A branch circuit with GFCI protection is run underground in UF cable. What is the minimum cover?
• 6005What is the minimum cover for direct burial cable installed under a 4 in thick concrete slab with no vehicular traffic that extends at least 6 in beyond the installation?
• 6006What is the minimum cover for any wiring method installed under a public street, highway, alley, or commercial parking lot?
• 6007Direct buried conductors emerging from grade must be protected by enclosures or raceways to what height above finished grade?
• 6009NEC 2026 expanded the underground warning ribbon requirement for service conductors to also include
• 6010What does the Code require for backfill around underground cables and raceways?
• 6012When a cable is installed through a bored hole in a wood stud, how far must the edge of the hole be from the nearest edge of the stud unless a steel plate is used?
• 6013NM cable passes through holes in metal studs that are punched at the factory. What must be done?
• 6014A cable run parallel to a wood framing member must be kept at least how far from the nearest edge of the member where nails or screws are likely to penetrate?
• 6017Where ungrounded conductors 4 AWG or larger enter an enclosure through a raceway, what is required at the entry?
• 6018NEC 2026 added a requirement in 300.4 for conductors and wiring methods that have been
• 6019EMT must be securely fastened within what distance of each outlet box, junction box, or termination?
• 6020What is the maximum distance between supports for EMT under the general rule?
• 6021Rigid metal conduit must generally be secured within what distance of each box or termination?
• 6022Trade size 1 rigid PVC conduit must be supported at intervals not exceeding
• 6023Expansion fittings are required in a run of PVC conduit where the expected length change due to temperature is at least
• 6024NM cable must be secured at intervals not exceeding
• 6025NM cable must be secured within what distance of every cable entry into an enclosure such as an outlet box?
• 6027Type MC cable must generally be secured within 12 in of each box and at intervals not exceeding
• 6028Type AC cable must be secured within 12 in of each box and at intervals not exceeding
• 6034In NEC 2026, the 360 degree limit on bends between pull points applies
• 6035A conduit run between two boxes has two 90 degree bends and four 30 degree offset bends. How many more degrees of bend may be added before a pull point is required?
• 6036After cutting EMT, what must be done to the cut ends?
• 6037What is the maximum percent fill of a conduit containing three or more conductors?
• 6038A conduit nipple not exceeding 24 in long between boxes may be filled to what percent of its area?
• 6039When calculating conduit fill, how are equipment grounding conductors treated?
• 6040What volume allowance does the box fill table assign to each 12 AWG conductor?
• 6041In a box fill calculation, a single receptacle on one yoke counts as
• 6042Two equipment grounding conductors enter a box. How are they counted for box fill?
• 6043A box contains four 12 AWG circuit conductors, two 12 AWG EGCs, and one switch on a single yoke. No clamps or fittings. What is the minimum box volume?
• 6044Outlet boxes for ceiling-suspended paddle fans must be listed and marked for fan support. What is the maximum fan weight such a box may support?
• 6045An outlet box at a ceiling luminaire outlet must be designed to support a luminaire weighing at least
• 6046In NEC 2026, a ceiling outlet box in a dwelling bedroom in a location typical for a paddle fan must
• 6047In a wall of noncombustible material such as concrete or tile, a box may be set back from the finished surface by not more than
• 6048Outlet and device boxes that do not enclose devices or utilization equipment must have an internal depth of at least
• 6050For a straight pull through a pull box containing 4 AWG or larger conductors, the box length must be at least how many times the largest raceway trade size?
• 6051For an angle pull, a trade size 3 and a trade size 2 conduit enter the same wall of a pull box. What is the minimum distance to the opposite wall?
• 6052What is required on every box in a completed installation?
• 6054What does the designation THHN indicate?
• 6055What is the temperature rating of THWN-2 insulation in a wet location?
• 6056XHHW insulation, without the -2 suffix, is rated 90 C in dry and damp locations and what in wet locations?
• 6057Which location is classified as a wet location?
• 6063Which use of a flexible cord is prohibited?
• 6066Which location permits Type NM cable?
• 6067In an attic reached only by a scuttle hole, NM cable run across the top of joists must be protected by guard strips within what distance of the scuttle hole?
• 6068In an unfinished basement, NM cable run at angles to joists must be run through bored holes or on running boards if it is smaller than
• 6069The ampacity of NM cable conductors is generally determined using which temperature column?
• 6070Which is a permitted use of Type UF cable?
• 6071Where rigid PVC conduit is exposed above grade and subject to physical damage, it must be

Equipment, Devices and Luminaires

• 7027A hallway light must be controlled from three separate locations. Which combination of switches is used?
• 7028How many traveler terminals does a standard four-way switch have, not counting the grounding terminal?
• 7029In a three-way switch circuit, which terminal of the switch at the supply end connects to the incoming ungrounded conductor?
• 7030How must each circuit be identified on a panelboard circuit directory?
• 7031Which panelboard directory entry best meets the code?
• 7032The old limit of 42 overcurrent devices for lighting and appliance branch-circuit panelboards was removed in the 2008 NEC. What limits the number of devices today?
• 7033A plug-in circuit breaker is back-fed to supply a panelboard. How must it be installed?
• 7034What is the maximum rating of the overcurrent device protecting a panelboard?
• 7035In a commercial building, a panelboard is supplied by a feeder from another panel. What must the panelboard be marked with?
• 7036In a panelboard supplied by a 4-wire delta system with a high leg, which phase position must the high leg occupy?
• 7037In a dwelling unit, where are overcurrent devices such as a panelboard not permitted?
• 7038Which type of luminaire is not permitted in a clothes closet?
• 7039What is the minimum clearance between a surface-mounted LED luminaire with a completely enclosed light source and the closet storage space?
• 7040A recessed LED luminaire with a completely enclosed light source is installed in a closet ceiling. What is the minimum clearance to the storage space?
• 7041A surface-mounted fluorescent luminaire is installed on a closet ceiling. What is the minimum clearance to the storage space?
• 7042Which item is prohibited within 3 ft horizontally and 8 ft vertically of a bathtub rim?
• 7043A luminaire in the bathtub zone is subject to shower spray. What must it be marked for?
• 7044A recessed luminaire that is not identified as Type IC is installed in an insulated ceiling. How far must thermal insulation be kept from the luminaire?
• 7045What does a Type IC marking on a recessed luminaire mean?
• 7046What is the maximum luminaire weight an outlet box may support unless the box is listed and marked for more?
• 7047Fluorescent luminaires with double-ended lamps and ballasts in a commercial building need what feature for servicing?
• 7048A fixed storage water heater holds 50 gallons. What is the minimum branch-circuit rating based on the nameplate?
• 7049A 4500 watt, 240 volt storage water heater is installed. What minimum ampacity must the branch circuit provide?
• 7050A built-in dishwasher is cord-and-plug connected. What cord length is permitted?
• 7051What cord length is permitted for a cord-and-plug connected kitchen waste disposer?
• 7052A permanently connected appliance is rated 250 VA. What may serve as its disconnecting means?
• 7053A permanently connected appliance rated above 300 VA is not within sight of its branch-circuit breaker. What is required?
• 7056What does Article 424 require for fixed electric space-heating equipment?
• 7058Which use of flexible cord is not permitted?
• 7059A flexible cord is run from one room to another through a hole in the wall. Is this permitted?
• 7060How must a flexible cord be connected so that tension is not transmitted to joints or terminal screws?
• 7061Equipment operating at 120/240 volts has exposed live parts on one side and no live or grounded parts on the other side of the working space (Condition 1). What is the minimum working space depth?
• 7062A 480Y/277 volt panelboard faces a concrete wall across the working space (Condition 2). What is the minimum working space depth?
• 7063Two 480 volt switchboards with exposed live parts face each other across an aisle (Condition 3). What is the minimum working space depth?
• 7064What is the minimum width of the working space in front of a 200 ampere panelboard that is 20 in wide?
• 7065What is the minimum headroom of the working space for service equipment and panelboards rated 1000 volts or less?
• 7066Equipment rated 800 amperes or more has its working space within 25 ft of a personnel door. What must the door have?
• 7067What does the dedicated electrical space above a panelboard extend to?
• 7072Under NEC 2026, which equipment needs arc flash hazard marking under 110.16?

Motors, HVAC, Generators and Transformers

• 8001Branch-circuit conductors supplying a single continuous-duty motor must have an ampacity of at least what percentage of the motor full-load current?
• 8002A continuous-duty motor has a table full-load current of 28 A. What is the minimum ampacity of its branch-circuit conductors?
• 8003When sizing motor branch-circuit conductors and short-circuit protection for a general-purpose motor, which current must be used?
• 8004Which value is used to size separate motor overload protection?
• 8005A motor with a marked service factor of 1.15 needs a separate overload device. What is the maximum rating as a percentage of nameplate full-load current?
• 8006A motor is marked with a temperature rise of 40 degrees C. What overload rating is permitted as a percentage of nameplate current?
• 8007A motor has a service factor of 1.0 and no temperature rise marking. What is the maximum overload rating?
• 8008A motor with a service factor of 1.0 has a nameplate current of 20 A. What is the maximum separate overload setting under 430.32(A)(1)?
• 8009The overload selected at 125 percent is not enough to start a motor with a service factor of 1.15. What is the highest rating the next step permits?
• 8010How many overload units are required for a three-phase ac motor?
• 8011What is the maximum rating of an inverse time breaker used as motor branch-circuit short-circuit and ground-fault protection for a standard squirrel cage motor?
• 8012What is the maximum rating of a dual-element time-delay fuse used as motor branch-circuit short-circuit and ground-fault protection?
• 8013What is the maximum rating of a nontime delay fuse used for motor branch-circuit short-circuit and ground-fault protection?
• 8014What is the maximum setting of an instantaneous trip breaker for a squirrel cage motor other than Design B energy efficient?
• 8015The calculated motor short-circuit protection value does not match a standard size. What does 430.52 permit?
• 8016A three-phase motor has a table full-load current of 40 A. What is the maximum inverse time breaker rating for its branch circuit, without using exceptions?
• 8017A motor has a table full-load current of 22 A. Dual-element fuses are used for branch-circuit short-circuit protection. What is the maximum standard fuse size, applying the next higher size rule?
• 8019Under NEC 2026, what may not be installed between the output terminals of power conversion equipment, such as a variable frequency drive, and the motor?
• 8020Where must a motor disconnecting means be located in relation to the motor and driven machinery?
• 8021What does the NEC mean when it says equipment is in sight from other equipment?
• 8022What is the minimum ampere rating of a motor disconnecting means for a motor rated 1000 volts or less?
• 8023A motor disconnect switch for a 10 hp motor must be rated in which unit?
• 8024How many conductors must a motor disconnecting means open?
• 8025What must a motor disconnecting means clearly indicate?
• 8027What is the minimum rating of a motor controller?
• 8028Where must the disconnecting means for a motor control circuit be arranged?
• 8031Under NEC 2026, where are general Class 1 circuit rules found?
• 8032What does the code letter on a motor nameplate indicate?
• 8034Feeder conductors supplying several motors must have an ampacity of at least what?
• 8035A feeder supplies three motors with table FLCs of 40 A, 20 A and 10 A. What is the minimum feeder conductor ampacity?
• 8036How is the maximum feeder short-circuit and ground-fault protective device for a motor feeder determined?
• 8037The largest motor on a feeder has a 100 A branch-circuit breaker. The other motors have FLCs of 20 A and 10 A. What is the maximum standard feeder breaker size?
• 8038When may several motors be connected to a single branch circuit?
• 8039Which nameplate value is used to size branch-circuit conductors for a packaged air conditioning unit?
• 8040An air conditioning unit nameplate shows a maximum overcurrent protection (MOCP) of 40 A. What breaker is permitted?
• 8041Where must the disconnecting means for an outdoor air conditioning condenser be located?
• 8043A rooftop HVAC unit requires a service receptacle. What is the maximum distance from the equipment?
• 8044What other location rule applies to the HVAC service receptacle?
• 8045May the HVAC service receptacle be connected to the load side of the equipment disconnecting means?
• 8046Branch-circuit conductors for a single hermetic motor-compressor must have an ampacity of at least what?
• 8047What is the normal maximum branch-circuit short-circuit protection for a single hermetic motor-compressor?
• 8048A single-phase cord-and-plug connected room air conditioner needs what protection device in or on the cord?
• 8049A room air conditioner is the only load on a 20 ampere individual branch circuit. What is its maximum marked rating?
• 8050A room air conditioner shares a branch circuit with lighting outlets. What is its maximum rating?
• 8052Conductors from generator terminals to the first overcurrent device must have an ampacity of at least what?
• 8053A 20 kW, 240 volt single-phase generator supplies a distribution panel. What is the minimum ampacity of the conductors from the generator terminals to the first overcurrent device?
• 8057Within how many seconds must an emergency system provide power after loss of normal supply?
• 8058Within how many seconds must a legally required standby system provide power after loss of normal supply?
• 8061A transformer rated 1000 volts or less has primary protection only, and the primary current is 9 A or more. What is the maximum primary overcurrent device rating?
• 8062A small control transformer has a primary current of 5 A and primary protection only. What is the maximum primary overcurrent device rating?
• 8063A transformer with primary-only protection has a rated primary current below 2 A. What is the maximum primary overcurrent device rating?
• 8064A transformer rated 1000 volts or less has both primary and secondary protection. What is the maximum primary device rating?
• 8065With primary and secondary protection, what is the maximum secondary device rating for a transformer with a secondary current of 9 A or more?
• 8066A 45 kVA, 480 volt three-phase transformer has primary-only protection. What is the maximum standard primary breaker size?
• 8067What must be done regarding the ventilation of a transformer?
• 8068A 75 kVA dry-type transformer is installed indoors. What is the minimum separation from combustible material without a fire-resistant barrier?
• 8072Oil-insulated transformers installed indoors are generally required to be installed in what?
• 8074Secondary conductors leave a transformer and do not exceed 10 ft in length. What may they terminate in without protection at the secondary terminals?
• 8075Capacitors rated 1000 volts or less must discharge their residual voltage to what level within what time after disconnection?
• 8076What is the minimum ampacity of conductors supplying a capacitor?
• 8078Why are capacitors installed in motor circuits in industrial plants?

Special Occupancies

• 9001A room where flammable gases or vapors from flammable liquids may be present in quantities sufficient to produce an ignitible mixture is classified as which class?
• 9002A location is hazardous because of the presence of combustible dust. Which class applies under the class and division system?
• 9003A cotton gin where easily ignitible fibers are handled, but not normally suspended in the air in ignitible quantities, is generally classified as which class?
• 9004In a Class I location, what distinguishes a Division 2 area from a Division 1 area?
• 9005Under the zone system for flammable gases and vapors, which zone describes a location where ignitible concentrations are present continuously or for long periods?
• 9006Zone 20, Zone 21, and Zone 22 classifications are used for which hazard?
• 9007Gasoline and propane are placed in which material group for Class I locations?
• 9008Hydrogen belongs to which Class I material group?
• 9009An atmosphere containing combustible magnesium or aluminum dust is assigned to which Class II group?
• 9010A grain elevator handling flour and grain dust is classified as Class II, Group ____.
• 9016Which wiring method is generally permitted in a Class I, Division 1 location?
• 9018Enclosures for equipment in a Class II, Division 1 location must generally be of what type?
• 9019What is the basic design principle of explosionproof equipment?
• 9020Intrinsically safe systems covered by Article 504 rely on which protection principle?
• 9021At a motor fuel dispensing facility, how is the area up to 18 in above grade within 20 ft horizontally of a dispenser enclosure classified?
• 9022The emergency electrical disconnect for fuel dispensers must open which conductors of the circuits to the dispensing equipment?
• 9026In a major repair garage for gasoline vehicles without the specified mechanical ventilation, how is the floor area up to 18 in above the floor classified?
• 9029In health care facilities, a patient care space where failure of equipment or the electrical system is likely to cause major injury or death is which category?
• 9030A patient care space in which failure of equipment is likely to cause only minor injury to patients or caregivers is classified as which category?
• 9031Branch circuits serving patient care spaces must provide two equipment grounding paths. Which combination meets this requirement?
• 9035The essential electrical system of a hospital is divided into which branches?
• 9036Article 518 for assembly occupancies applies to buildings or portions of buildings designed for the gathering of how many persons or more?
• 9039At a carnival, circus, or fair, 125-volt, single-phase, 15- and 20-ampere receptacles used by personnel or readily accessible to the public require what protection?
• 9057On a construction site, a 125-volt, single-phase, 20-ampere receptacle on a temporary power pole used by workers requires what protection?
• 9058Temporary electrical power for holiday decorative lighting is limited to a maximum period of how many days?
• 9059When must temporary wiring installed for construction be removed?

Special Equipment, Pools, PV and EV

• 10001Each commercial building and occupancy accessible to pedestrians must have at least one outlet for sign or outline lighting at each tenant entrance. What branch circuit must supply it?
• 10003What does Article 600 require of the disconnecting means for a sign?
• 10004Which statement about fixed electric signs is correct?
• 10005What is required of the main disconnecting means for an elevator?
• 10009When may an information technology equipment room use the special provisions of Article 645?
• 10011Branch-circuit conductors supplying information technology equipment under Article 645 must have an ampacity of not less than what percentage of the total connected load?
• 10012What is the minimum horizontal distance from the inside wall of a permanently installed pool for a general purpose 125-volt receptacle?
• 10013125-volt, 15- and 20-ampere receptacles located within what distance of the inside walls of a pool require GFCI protection?
• 10014At a dwelling with a permanently installed pool, where must the required 125-volt, 15- or 20-ampere receptacle be located?
• 10016Over an outdoor pool, what is the minimum height of a luminaire or ceiling fan above the maximum water level?
• 10017In an indoor pool area, the minimum height for a luminaire over the pool may be reduced to what height if the luminaire is totally enclosed and GFCI protected?
• 10018Switching devices must be located at least how far horizontally from the inside walls of a pool, unless separated by a solid fence, wall, or permanent barrier?
• 10020Unless listed for a lesser depth, the top of the lens of a wet-niche luminaire must be at least how far below the normal water level?
• 10021A branch circuit supplies an underwater pool luminaire operating above the low-voltage contact limit. What protection is required?
• 10022For sinusoidal ac, the low-voltage contact limit used in Article 680 is how many volts RMS?
• 10025What is the minimum size of a solid copper equipotential bonding conductor for a permanently installed pool?
• 10026In NEC 2026, which material is newly recognized as an alternative to the 8 AWG copper equipotential bonding conductor and copper bonding grid for pools?
• 10027Perimeter surfaces around a pool must be bonded for what minimum horizontal distance beyond the inside walls?
• 10030For conductive pool shells, perimeter surface bonding must attach to the structural reinforcing steel or copper grid at a minimum of how many points?
• 10031Pool water must be bonded by a conductive surface in contact with the water of at least what area?
• 10032Metal parts such as fences or railings must be bonded when within what distance of the inside walls of a pool, unless separated by a permanent barrier?
• 10033A commercial spa requires an emergency shutoff for the recirculation and jet system. Where must it be installed?
• 10036How must a hydromassage bathtub be supplied?
• 10038For a fountain, which equipment requires GFCI protection unless it is listed for operation at low voltage?
• 10041Under NEC 2026, as amended by TIA 26-1, where may ground-fault protection NOT be installed for a variable-speed pool motor that uses an adjustable-speed drive?
• 10042A pool pump motor is connected to a single-phase, 240-volt, 20-ampere branch circuit. What protection is required for the outlet?
• 10044What is the maximum PV system voltage permitted for PV systems on one- and two-family dwellings?
• 10045What is the maximum PV system voltage on or in buildings other than one- and two-family dwellings?
• 10046A PV module has a short-circuit current (Isc) of 10 amperes. Using the standard method, what is the maximum circuit current for that PV circuit?
• 10047A single PV string has modules with an Isc of 10 amperes. What is the minimum conductor ampacity before adjustment and correction, applying both 125 percent factors?
• 10049Under PV rapid shutdown rules, conductors outside the array boundary must be reduced to no more than what voltage within 30 seconds of initiation?
• 10050For PV rapid shutdown, the array boundary is defined as what distance from the array in all directions?
• 10052For one- and two-family dwellings, where must the PV rapid shutdown initiation device be located?
• 10053A PV system has dc circuits operating at 80 volts or more between any two conductors. What protection is required?
• 10055A PV module has an open-circuit voltage (Voc) of 40 volts. Ten modules are connected in series, and the temperature correction factor for the lowest expected ambient temperature is 1.12. What is the maximum PV circuit voltage?
• 10056A PV module has a temperature-corrected Voc of 48 volts. What is the maximum number of modules that can be connected in series on a one- and two-family dwelling?
• 10064What protection is required for receptacles installed for the connection of EV charging equipment?
• 10065An EVSE has a maximum load of 48 amperes. What is the minimum OCPD rating for the branch circuit supplying it?
• 10066An EVSE is rated 40 amperes continuous. What is the minimum OCPD rating for its branch circuit?
• 10067How must each outlet installed for EVSE be supplied?
• 10068Indoor EV charging equipment is listed as requiring ventilation. What does the NEC require?
• 10070Under NEC 2026, which EVSE requires a disconnecting means installed in a readily accessible location?
• 10072Under NEC 2026, a 50-ampere receptacle used for EVSE connection must meet which requirement?
• 10073Under NEC 2026, may a 50-ampere receptacle for EVSE be installed on a 40-ampere branch circuit as 210.24 would otherwise allow?
• 10076The OCPD for a fire pump motor must be sized to carry what current indefinitely?
• 10078Under NEC 2026, fire pump supply and control conductors inside a building protected by concrete encasement require at least how much concrete?
• 10083A transformer arc welder has a rated primary current of 50 amperes and a 50 percent duty cycle. The I1eff value is not marked. Using a duty cycle multiplier of 0.71, what is the minimum supply conductor ampacity?
• 10084The OCPD for an arc welder may be rated at not more than what percentage of the rated primary current (I1max)?

Emergency, Limited Energy and Communications

• 11001Upon failure of the normal supply, emergency system power must be available within what time?
• 11002Upon failure of the normal supply, a legally required standby system must have power available within what time?
• 11003Which type of alternate power system has no NEC-specified maximum time for power to be restored?
• 11004How must emergency system wiring generally be installed in relation to other wiring?
• 11005What type of transfer equipment is required for an emergency system?
• 11009How must emergency lighting systems be designed with respect to lamp failure?
• 11010Where on-site emergency power sources are installed, a sign must be placed where?
• 11011Which record must be kept for an emergency system?
• 11013In assembly occupancies for more than 1000 persons or buildings above 75 ft in height, emergency feeder circuit wiring must have what protection?
• 11016Egress lighting required by a building code to illuminate exit paths during a power outage is part of which system?
• 11017A code-required system supplies sewage disposal pumps and smoke removal equipment during outages, with less urgency than egress lighting. Which system is this?
• 11018A portable generator is connected to a dwelling's premises wiring as an optional standby source. What is required?
• 11020In NEC 2026, energy management systems and power control systems are covered by which article?
• 11032What identification is required on the disconnecting means for a fire alarm branch circuit?
• 11033Which power-limited fire alarm cable type is suitable for installation in plenums?
• 11034What does the NEC require for the accessible portion of abandoned fire alarm cable?
• 11035Where must fire alarm circuits be identified?
• 11038In NEC 2026, where are optical fiber cable requirements located after Article 770 was removed?

Load Calculations

• 12001Using the standard method under the NEC 2026, what general lighting load must be included in the service calculation for a one-family dwelling with 2,400 ft2 of livable floor area?
• 12002A 2,000 ft2 dwelling has the minimum two small-appliance circuits and one laundry circuit. Under the NEC 2026 standard method, what is the demand load for general lighting, small-appliance and laundry loads combined?
• 12003A 3,200 ft2 one-family dwelling has three 20 A small-appliance circuits and one laundry circuit. Under the NEC 2026 standard method, what is the net demand load for these loads plus general lighting?
• 12004Under the NEC 2026 standard method, what is the demand load for general lighting, two small-appliance circuits and one laundry circuit in a 4,500 ft2 dwelling?
• 12005Optional method (NEC 2026): a 2,000 ft2 dwelling has two small-appliance circuits, one laundry circuit, a 12 kW range, a 5 kW dryer, a 1,200 VA dishwasher and a 4,500 W water heater. What is the calculated general load (heating and AC excluded)?
• 12006Optional method (NEC 2026), 120/240 V service: 1,800 ft2 dwelling, two small-appliance and one laundry circuit, 11 kW range, 5.5 kW dryer, 1,000 VA dishwasher, 800 VA disposal, 4 kW water heater, 6,000 VA central AC and 8 kW central electric furnace. What is the calculated load in amperes?
• 12007Optional method (NEC 2026): a 1,500 ft2 dwelling with two small-appliance and one laundry circuit, a 10 kW range, 5 kW dryer and 4.5 kW water heater has six separately controlled 2 kW baseboard heaters and a 4,000 VA AC unit. What is the total calculated load?
• 12009Under the NEC 2026, what is the minimum number of 15 A, 120 V general lighting branch circuits for a 2,600 ft2 dwelling?
• 12010How many 20 A, 120 V general lighting branch circuits are required at minimum for a 3,400 ft2 dwelling under the NEC 2026?
• 12011Under the NEC 2026, what is the feeder demand load for four 5.5 kW household electric dryers in an apartment building?
• 12012Five 5 kW household dryers are supplied by one feeder. What is the calculated dryer load under the NEC 2026?
• 12013Ten 5 kW electric dryers in a multifamily building are on one service. Using the NEC 2026 dryer demand factors, what is the dryer load?
• 12014Under the NEC 2026, what is the demand factor for 15 household electric dryers on one feeder?
• 12015A dwelling has one electric dryer rated 4,400 W. What load must be used for it in the NEC 2026 service calculation?
• 12016Standard method (NEC 2026): a dwelling has a 1,500 VA dishwasher, 1,000 VA disposal, 4,500 W water heater and 800 VA microwave, all fastened in place. What is the demand load for these appliances?
• 12017Standard method (NEC 2026): the only fastened-in-place appliances are a 1,200 VA dishwasher, a 900 VA disposal and a 5,000 W water heater. What appliance load goes into the calculation?
• 12033Under the NEC 2026 load calculation rules, an EVSE in a dwelling has no nameplate rating available. What load is used for it?
• 12034A 24 A, 240 V EVSE with a nameplate rating of 5,760 VA is added to a one-family dwelling. What EVSE load is used in an NEC 2026 standard method calculation?
• 12035A 48 A continuous EVSE operates at 240 V. What load does it add to an NEC 2026 dwelling service load calculation?
• 12036In the NEC 2026 optional method for a single dwelling, how is a 9,600 VA EVSE treated?
• 12037NEC 2026 standard method: a dwelling has a 1,200 VA dishwasher, 900 VA disposal, 4,500 W water heater and a 7,680 VA EVSE. What is the combined load for these four items?
• 12038NEC 2026 optional method: 2,200 ft2 dwelling, two small-appliance and one laundry circuit, 12 kW range, 5 kW dryer, 1,200 VA dishwasher, 900 VA disposal, 4.5 kW water heater, 5,000 VA AC (larger than heat) and a 9,600 VA EVSE. What is the total calculated load?
• 12040Which statement about the 2 VA per ft2 dwelling unit load in the NEC 2026 is correct?
• 12041Under the NEC 2026, what load is included for each 2-wire small-appliance branch circuit in a dwelling unit?
• 12043Under the NEC 2026, what is the calculated load for 3 household electric dryers rated 5,500 W each on one feeder?
• 12044Under the NEC 2026, what is the calculated load for 6 household electric dryers rated 5,000 W each on one feeder?
• 12045Under the NEC 2026, what is the calculated load for 8 household electric dryers rated 6,000 W each on one feeder?
• 12046Under the NEC 2026, what is the calculated load for 30 household electric dryers rated 5,000 W each on one feeder?
• 12047Under the NEC 2026, what is the calculated load for 2 household electric dryers rated 5,000 W each on one feeder?
• 12048Under the NEC 2026, what is the calculated load for 45 household electric dryers rated 5,000 W each on one feeder?
• 12056Which dwelling load contributes nothing to the neutral in an NEC 2026 feeder calculation?
• 12058A 10-unit apartment building has 1,000 ft2 units, each with two small-appliance circuits and one laundry circuit. What is the NEC 2026 standard method demand for lighting, small-appliance and laundry loads on the service?

Electrical Calculations

• 13001A resistive heating element has a resistance of 15 ohms and is connected to 120 volts. What current does it draw?
• 13002A 4,800 watt resistive water heater is connected to a 240 volt single-phase circuit. What is the current?
• 13003What is the resistance of a 1,500 watt, 120 volt space heater element at its rated operating point?
• 13004A heater rated 4,000 watts at 240 volts is connected to a 208 volt supply. Assuming constant resistance, about how much power will it produce?
• 13005A current of 10 amperes flows through a conductor path with a total resistance of 0.5 ohm. How much power is lost as heat in the conductors?
• 13006A balanced three-phase 480 volt resistive load is rated 50 kW. What is the line current?
• 13007What is the full-load line current of a balanced 30 kVA three-phase load supplied at 208 volts?
• 13008A single-phase 240 volt resistive load draws 32 amperes. What is the load in kilowatts?
• 13009A three-phase 480 volt motor draws 40 amperes per line at a power factor of 0.85. What is the true power input?
• 13010A load consumes 72 kW at a power factor of 0.80. What is the apparent power?
• 13011A load has an apparent power of 100 kVA and a power factor of 0.80. What is its reactive power?
• 13012A motor delivers 10 horsepower at the shaft while drawing 8.5 kW of electrical input. What is its efficiency?
• 13013A motor takes 20 kW of electrical input and operates at 90 % efficiency. What is its output in horsepower?
• 13014A three-phase 460 volt motor delivers 25 hp with an efficiency of 92 % and a power factor of 0.86. What is the actual line current (not the NEC table value)?
• 13015A single-phase 240 volt load draws 50 amperes, and a wattmeter reads 10.2 kW. What is the power factor?
• 13016A 5 kW resistance heater runs 8 hours per day. At $0.12 per kWh, what does one day of operation cost?
• 13017A 15 kW balanced three-phase resistive heater is connected to 208 volts. What is the line current?
• 13018A 120/240 volt single-phase 3-wire feeder carries 40 A on one ungrounded conductor and 25 A on the other. Assuming linear loads, what current flows in the neutral?
• 13019A 3-phase 4-wire wye feeder has linear loads of 50 A on phase A, 40 A on phase B and 30 A on phase C. What is the approximate neutral current?
• 13020What is the line-to-neutral voltage of a 480Y/277 volt system, calculated from the 480 volt line-to-line value?
• 13021Each winding of a balanced delta-connected load carries 20 amperes. What is the line current?
• 13022What is the apparent power of a three-phase 480 volt load drawing 100 amperes per line?
• 13023A plant load of 100 kW operates at 0.80 power factor. About how much capacitor kVAR is needed to raise the power factor to 0.95?
• 13024Resistors of 6, 3 and 2 ohms are connected in parallel. What is the total resistance?
• 13025A 10 ohm and a 15 ohm resistor are connected in parallel. What is the equivalent resistance?
• 13026A 4 ohm resistor is connected in series with a parallel group of 6 ohms and 12 ohms, and the circuit is supplied at 120 volts. What is the total current?
• 13027Four identical 40 ohm heating elements are connected in parallel. What is the combined resistance?
• 13028Resistors of 5, 10 and 15 ohms are connected in series across 120 volts. What is the voltage across the 10 ohm resistor?
• 13031A 120 volt single-phase branch circuit uses 12 AWG copper (6,530 circular mils), runs 100 feet one way and carries 16 A. Using K = 12.9, what is the voltage drop?
• 13032A 240 volt single-phase circuit of 10 AWG copper (10,380 circular mils) supplies 24 A at 150 feet one way. What is the voltage drop as a percentage of the supply voltage?
• 13033A three-phase 480 volt load draws 50 A over 6 AWG copper conductors (26,240 circular mils), 200 feet one way. What is the line-to-line voltage drop?
• 13034A 240 volt single-phase feeder uses 4 AWG aluminum conductors (41,740 circular mils), 175 feet one way, carrying 60 A. Using K = 21.2 for aluminum, what is the voltage drop?
• 13035A 240 volt single-phase load of 40 A is located 180 feet from the panel. What is the smallest copper conductor that keeps voltage drop at or below 3 %?
• 13036A three-phase 208 volt load of 90 A is 150 feet from the source. Ignoring ampacity, what is the smallest copper conductor that limits voltage drop to 3 %?
• 13037A three-phase 480 volt load of 100 A is 300 feet away. Ignoring ampacity, what is the smallest aluminum conductor that holds voltage drop to 3 %?
• 13038What is the maximum one-way length for a 120 volt circuit of 12 AWG copper (6,530 circular mils) carrying 16 A if voltage drop must not exceed 3 %?
• 13039A 240 volt single-phase circuit of 8 AWG copper (16,510 circular mils) runs 120 feet one way. What is the maximum load current that keeps voltage drop at 3 %?
• 13040A 240 volt single-phase load draws 50 A through 6 AWG copper (26,240 circular mils) that is 200 feet long one way. What voltage is available at the load?
• 13041On a single-phase circuit, the length of the run is doubled and the load current is cut in half, with the same conductor. What happens to the voltage drop?
• 13042What voltage corresponds to a 3 % voltage drop on a 208 volt branch circuit?
• 13043In the common voltage drop formula VD = 2KIL / CM, what K value is normally used for aluminum conductors?
• 13044A three-phase 208 volt circuit of 10 AWG copper (10,380 circular mils) supplies 25 A per phase at 120 feet one way. What is the percent voltage drop?
• 13045A 120 volt, 20 A load is 150 feet from the panel. What is the smallest copper conductor that keeps voltage drop at or below 3 %?
• 13046What is the allowable ampacity of 6 AWG THHN copper (90 °C column) with three current-carrying conductors in a raceway at an ambient temperature of 40 °C?
• 13047Six current-carrying 10 AWG THHN copper conductors share one raceway at 30 °C ambient. What is the adjusted ampacity from the 90 °C column?
• 13048Nine current-carrying 12 AWG THHN copper conductors are installed in one conduit at 30 °C ambient. What is the adjusted ampacity of each conductor based on the 90 °C column?
• 13049Eight current-carrying 12 AWG THHN copper conductors run through an area with a 45 °C ambient. What is the allowable ampacity using the 90 °C column?
• 13050What is the ampacity of 4 AWG THWN copper (75 °C insulation) with three current-carrying conductors at an ambient of 45 °C?
• 13051Four current-carrying 3/0 AWG THWN-2 copper conductors are installed in a raceway where the ambient is 50 °C. What is the derated ampacity from the 90 °C column?
• 13052Six current-carrying 8 AWG THHN copper conductors are in one raceway at 30 °C ambient, and all terminations are rated 75 °C. What is the maximum ampacity that may be used for each conductor?
• 13053Three current-carrying 2 AWG THHN copper conductors are installed at 35 °C ambient and terminate on 75 °C rated lugs. What is the maximum load current the conductors may be used for?
• 13054A raceway contains two 3-phase, 4-wire wye circuits, and the loads are mainly electronic (nonlinear), so the neutrals count as current-carrying. Equipment grounding conductors are also present. What adjustment factor applies?
• 13055A raceway holds three 120 volt, 2-wire branch circuits, each with its own neutral, plus one equipment grounding conductor per circuit. How many current-carrying conductors are counted for adjustment?
• 13056A raceway contains three 120/240 volt, single-phase 3-wire multiwire circuits. The neutrals carry only unbalanced current. What adjustment factor applies to the conductors?
• 13057What is the allowable ampacity of 4/0 AWG XHHW aluminum conductors in the 75 °C column at 30 °C ambient with not more than three current-carrying conductors?
• 1305812 AWG copper UF cable (60 °C rated) is installed where the ambient temperature is 40 °C. What is its corrected ampacity?
• 13059A 50 A noncontinuous load is supplied by one of six current-carrying THHN copper conductors in a raceway at 30 °C. Terminations are rated 75 °C. What is the smallest conductor size permitted?
• 13060Twenty current-carrying 12 AWG THHN copper conductors are in one raceway at 30 °C ambient. What is the adjusted ampacity based on the 90 °C column?
• 13061What adjustment factor applies when 25 current-carrying conductors are installed in a single raceway longer than 24 inches?
• 13062What ambient temperature correction factor applies to a 75 °C rated conductor at an ambient of 38 °C (tables based on 30 °C)?
• 13063A device box contains four 12 AWG insulated conductors, two 12 AWG equipment grounding conductors and one receptacle on a yoke. What minimum box volume is required?
• 13064A box has internal cable clamps, six 14 AWG insulated conductors, two 14 AWG equipment grounding conductors and a single-pole switch. What minimum volume does 314.16 require?
• 13065A box has a marked volume of 18.0 cubic inches and will contain only 12 AWG conductors with no fittings, devices or grounding conductors. What is the maximum number of conductors permitted?
• 13066A box contains four 12 AWG and two 14 AWG insulated conductors, 12 AWG equipment grounding conductors and a receptacle connected to the 12 AWG conductors. What minimum volume is required?
• 13067What is the volume listed in 314.16(A) for a 4 inch by 2-1/8 inch square metal box?
• 13068A 4 inch by 1-1/2 inch square box (21.0 cu in) has a plaster ring marked 3.6 cu in. What is the maximum number of 12 AWG conductors permitted if nothing else is in the box?
• 13069A box contains three 14 AWG insulated conductors that are spliced and terminated, two 14 AWG pigtails that originate and end inside the box, and one 14 AWG equipment grounding conductor group. What minimum volume is required?
• 13070Which volume allowance does 314.16(B) assign to each 6 AWG conductor?
• 13071A 4 inch by 1-1/2 inch octagonal box (15.5 cu in) will contain a fixture stud, four 14 AWG insulated conductors and one 14 AWG equipment grounding conductor. What volume is required, and does the box comply?
• 13072A 3 inch by 2 inch by 3-1/2 inch device box is rated 18.0 cu in. It holds a switch, two 14 AWG cables with grounds (4 insulated conductors) and internal clamps. How many additional 14 AWG insulated conductors may be added?
• 13073A conductor runs unbroken through a box without being spliced or terminated and is not looped. How is it counted for box fill?
• 13074What is the maximum fill percentage for a raceway that contains three or more conductors, other than a short nipple?
• 13075What maximum fill percentage applies when exactly two conductors are installed in a raceway?
• 13076A raceway nipple not exceeding 24 inches long between enclosures may be filled to what percentage?
• 13077Using a 40 % fill area of 0.213 sq in for 3/4 inch EMT and an area of 0.0133 sq in for 12 AWG THHN, how many 12 AWG THHN conductors are permitted?
• 13078How many 10 AWG THHN conductors (0.0211 sq in each) may be installed in 1/2 inch EMT, which has a 40 % fill area of 0.122 sq in?
• 13079Three 4 AWG THHN (0.0824 sq in each) and one 8 AWG THHN (0.0366 sq in) are to be installed in EMT. Which is the smallest trade size permitted? (40 % areas: 3/4 in 0.213, 1 in 0.346, 1-1/4 in 0.598 sq in)
• 13080What is the total cross-sectional area of six 10 AWG THHN (0.0211 sq in each) and three 8 AWG THHN (0.0366 sq in each) conductors?
• 130813/4 inch EMT has a 40 % fill area of 0.213 sq in and 14 AWG THHN has an area of 0.0097 sq in. How many 14 AWG THHN conductors are permitted when all conductors are the same size?
• 130821 inch EMT has a total internal area of 0.864 sq in. What is the maximum cross-sectional area of a single conductor installed in it?
• 13083A 25 hp, 460 volt, three-phase induction motor has a table full-load current of 34 A. What is the minimum ampacity of its branch-circuit conductors?
• 13084What minimum conductor ampacity is required for a 5 hp, 230 volt, single-phase motor? (Table full-load current 28 A.)
• 13085What is the full-load current from Table 430.250 for a 10 hp, 208 volt, three-phase induction motor, and the resulting minimum conductor ampacity?
• 13086A 20 hp, 460 volt, three-phase motor has a nameplate current of 26 A. Table 430.250 lists 27 A. What is the minimum branch-circuit conductor ampacity?
• 13087A 15 hp, 460 volt, three-phase squirrel-cage motor (not Design B energy efficient) has a table full-load current of 21 A. Using an inverse time breaker at its maximum percentage and the next-higher-size allowance, what breaker may be used?
• 13088A 10 hp, 230 volt, three-phase motor has a table full-load current of 28 A. What is the maximum dual-element time-delay fuse size under the basic percentage of 430.52?
• 13089A 30 hp, 460 volt, three-phase motor has a table full-load current of 40 A. What is the maximum nontime-delay fuse size, using the next-higher-standard-size allowance?
• 13090What is the maximum setting, under the basic table percentage, of an instantaneous trip breaker for a 10 hp, 460 volt, three-phase squirrel-cage motor with a table full-load current of 14 A?
• 13091A motor has a nameplate full-load current of 24 A and a marked service factor of 1.15. What is the maximum rating of a separate overload device under 430.32(A)(1)?
• 13092A motor has a nameplate current of 40 A, a service factor of 1.0 and a temperature rise of 50 °C. What overload rating is required under the basic rule?
• 13093A motor with a 1.15 service factor and a nameplate current of 24 A trips its overloads during starting. What is the highest overload rating permitted under 430.32(C)?
• 13094A feeder supplies three 460 volt, three-phase motors with table full-load currents of 14 A, 21 A and 34 A. What is the minimum feeder conductor ampacity?
• 13095A 1 hp, 115 volt, single-phase motor has a table full-load current of 16 A. What minimum branch-circuit conductor ampacity is required?
• 13096A feeder supplies three 460 volt motors: 25 hp (34 A) protected by a 90 A inverse time breaker, 15 hp (21 A) and 10 hp (14 A). What is the maximum rating of the feeder overcurrent device?
• 13097What is the Table 430.250 full-load current for a 50 hp, 230 volt, three-phase induction motor?
• 13098A 7.5 hp, 460 volt, three-phase motor has a table full-load current of 11 A. What minimum branch-circuit conductor ampacity is required?
• 13099Why does the full-load current from Table 430.250, rather than the motor nameplate current, determine motor branch-circuit conductor ampacity for a general-purpose motor?
• 13100A 25 kVA single-phase transformer has a 480 volt primary and a 240 volt secondary. What are the full-load primary and secondary currents?
• 13101What is the full-load secondary current of a 75 kVA, three-phase transformer with a 208Y/120 volt secondary?
• 13102What is the full-load primary current of a 75 kVA, three-phase transformer with a 480 volt delta primary?
• 13103A 45 kVA, three-phase, 480 volt primary transformer (1,000 volts or less) is protected on the primary side only. What is the maximum primary overcurrent device, using the next-higher-standard-size note?
• 13104A single-phase transformer steps 480 volts down to 120 volts. If the primary current is 10 A, what is the secondary current (ignoring losses)?
• 13105A transformer has a turns ratio of 20 to 1 and a primary voltage of 2,400 volts. What is the secondary voltage?
• 13106A balanced three-phase load draws 150 A per phase at 208 volts. What is the minimum transformer kVA required?
• 13107A transformer delivers 48.5 kW to its load while its input is 50 kW. What is its efficiency?
• 13108A 15 kVA, single-phase transformer with a 240 volt primary is protected on the primary side only. Which statement about its primary current is correct?
• 13109A branch circuit supplies a 36 A continuous load and nothing else. What is the minimum overcurrent device rating?
• 13110A 40 A continuous load is supplied with THWN copper conductors terminating on 75 °C rated equipment. What is the minimum conductor size?
• 13111A branch circuit supplies 30 A of continuous load and 20 A of noncontinuous load. What is the minimum standard overcurrent device rating?
• 13112What is the maximum continuous load permitted on a 20 A branch circuit protected by a standard (not 100 % rated) breaker?
• 13113What is the maximum continuous lighting load in volt-amperes on a 277 volt, 20 A branch circuit?
• 13114How many 277 volt LED luminaires drawing 0.75 A each may be connected to a 20 A branch circuit if they operate continuously?
• 13115A three-phase feeder supplies 120 A of continuous load and 40 A of noncontinuous load. What is the minimum standard overcurrent device rating?
• 13116A 24 A continuous load is supplied by a branch circuit. What is the minimum overcurrent device rating and minimum copper conductor size with 60 °C terminations?
• 13118A single-phase 240 volt, 10 kW heater operates for 3 hours. How many kilowatt-hours does it use, and what is its current?
• 13119What is the circular mil area of a 10 AWG conductor as listed in Chapter 9 Table 8?
• 13120A 240 volt, single-phase, 2 hp motor has a table full-load current of 12 A at 230 volts. What is the minimum branch-circuit conductor ampacity?
• 13121Three-phase 460 volt motors are rated 5 hp (7.6 A) and 3 hp (4.8 A). What is the minimum ampacity of a feeder supplying only these two motors?
• 13122A 9 kW, 480 volt, three-phase resistive heater is a continuous load. What is the minimum standard overcurrent device rating?
• 13123What is the inverse time breaker maximum for a 3 hp, 230 volt, single-phase motor (table FLC 17 A), allowing the next higher standard size?