Your FREE Journeyman Electrician License Exam Practice Test 2026 – 100+ Q&A

Journeyman Electrician Practice Questions

1. An electric range element has a resistance of 12 ohms and carries 10 amperes. According to Ohm's law, what is the voltage applied across the element?
   • 120 volts
   • 1.2 volts
   • 22 volts
   • 0.83 volts

   Correct answer: 120 volts

   120 volts is correct. Ohm's law in the form E = I × R multiplies current by resistance, so 10 amperes times 12 ohms equals 120 volts. Dividing the two values gives 1.2 or 0.83, and adding them gives 22, none of which is the product the formula requires.

2. Two resistances of 20 ohms each are connected in parallel across a source. What is the total resistance of the combination?
   • 40 ohms
   • 20 ohms
   • 400 ohms
   • 10 ohms

   Correct answer: 10 ohms

   10 ohms is correct. For two equal resistances in parallel, the total equals one value divided by the number of branches, so 20 ohms divided by two equals 10 ohms. Adding the resistances gives 40 ohms, which would apply to a series connection, while 20 and 400 ohms misapply the parallel relationship.

3. If the resistance of a circuit stays constant and the applied voltage is reduced to half its original value, what happens to the current according to Ohm's law?
   • The current doubles
   • The current stays the same
   • The current is reduced to half its original value
   • The current is reduced to one-quarter its original value

   Correct answer: The current is reduced to half its original value

   The current is reduced to half its original value is correct. Ohm's law $\left( I = \frac{E}{R} \right)$ makes current directly proportional to voltage when resistance is fixed, so halving the voltage halves the current. The current would only double if voltage doubled, and it does not stay the same because voltage directly determines the quotient.

4. A single-phase 120-volt circuit supplies a 1,200-watt resistive load. Using the single-phase power formula, what current does the load draw?
   • 0.1 amperes
   • 144,000 amperes
   • 100 amperes
   • 10 amperes

   Correct answer: 10 amperes

   10 amperes is correct. Rearranging the single-phase power formula to $I = \frac{P}{E}$ gives 1,200 watts divided by 120 volts, which equals 10 amperes. Inverting the division gives 0.1, multiplying the values gives 144,000, and 100 amperes misplaces the decimal.

5. A single-phase 277-volt lighting circuit carries 12 amperes at unity power factor. What is the approximate power delivered to the load?
   • 23 watts
   • 289 watts
   • 3,324 watts
   • 332 watts

   Correct answer: 3,324 watts

   3,324 watts is correct. Single-phase power at unity power factor equals voltage multiplied by current $(P = E \times I)$, so 277 volts times 12 amperes equals about 3,324 watts. Dividing the values gives 23, adding them gives 289, and 332 results from dropping a factor of ten.

6. A balanced three-phase, 240-volt load draws 40 amperes per line at unity power factor. What is the approximate total power consumed?
   • 9,600 watts
   • 16,628 watts
   • 28,800 watts
   • 5,543 watts

   Correct answer: 16,628 watts

   16,628 watts is correct. Three-phase power equals $\sqrt{3}$ times line voltage times line current, so $\sqrt{3} \times 240 \times 40$ equals about 16,628 watts. Omitting the 1.732 factor yields 9,600 watts, while the remaining figures result from misapplying the multiplier.

7. A balanced three-phase 480-volt circuit delivers 50,000 watts at unity power factor. What is the approximate line current?
   • 104 amperes
   • 60 amperes
   • 180 amperes
   • 35 amperes

   Correct answer: 60 amperes

   60 amperes is correct. Rearranging the three-phase power formula to $I = \frac{P}{\sqrt{3} \times E}$ gives 50,000 watts divided by the product of 1.732 and 480 volts, which equals about 60 amperes. Omitting the 1.732 factor gives 104 amperes, while the other choices misuse the multiplier.

8. On a two-wire, 240-volt branch circuit, a 20-ampere load is served over conductors having a total round-trip resistance of 0.25 ohm. What is the approximate voltage drop on the circuit?
   • 5 volts
   • 2.5 volts
   • 80 volts
   • 10 volts

   Correct answer: 5 volts

   5 volts is correct. Voltage drop equals current times the total conductor resistance (E = I × R), so 20 amperes times 0.25 ohm equals 5 volts. Halving the figure ignores that the round-trip resistance is already given, and the larger values come from dividing rather than multiplying.

9. A 240-volt feeder is permitted a maximum voltage drop of 3 percent at its farthest point according to the NEC informational-note recommendation. What is the largest voltage drop, in volts, that meets this guideline?
   • 3.6 volts
   • 12 volts
   • 7.2 volts
   • 24 volts

   Correct answer: 7.2 volts

   7.2 volts is correct. Three percent of the 240-volt nominal value equals $0.03 \times 240 = 7.2\,\text{V}$. The 12-volt figure is 5 percent, the 24-volt figure is 10 percent, and 3.6 volts is 3 percent of only 120 volts rather than 240.

10. Which of the following installation conditions tends to increase the voltage drop experienced by the load on a branch circuit?
    • Shortening the conductor run to the load
    • Increasing the length of the conductor run to the load
    • Replacing the conductors with a larger size
    • Reducing the current drawn by the load

    Correct answer: Increasing the length of the conductor run to the load

    Increasing the length of the conductor run to the load is correct. Voltage drop equals current times conductor resistance, and a longer run has more resistance, so lengthening the circuit raises the drop. Shortening the run, using larger conductors, or drawing less current all reduce either resistance or current and therefore lower the voltage drop.

11. A 208-volt branch circuit shows a measured voltage drop of 5.2 volts at its farthest outlet. What percentage of the nominal voltage does this represent?
    • 5 percent
    • 2.5 percent
    • 4 percent
    • 1.5 percent

    Correct answer: 2.5 percent

    2.5 percent is correct. Percent voltage drop equals the volts dropped divided by the nominal voltage, so $\frac{5.2}{208} = 0.025$, or 2.5 percent. This is within the 3 percent informational-note target for a branch circuit, and the other choices result from dividing incorrectly or misplacing the decimal.

12. For electrical equipment operating at 120 volts to ground and likely to require examination while energized, what is the minimum required depth of working space under Condition 1, where the space is clear with no live or grounded parts on the opposite side?
    • 3 feet
    • 3 feet 6 inches
    • 4 feet
    • 2 feet 6 inches

    Correct answer: 3 feet

    3 feet is correct. NEC Table 110.26(A)(1) requires 3 feet of clear working depth for equipment rated 0 to 150 volts to ground under all three conditions, including Condition 1. The 3-foot 6-inch depth applies to Condition 2 only at the 151 to 600 volt range, not at 120 volts to ground, where all three conditions require the same 3-foot minimum. The other depths do not match any standard condition for this voltage range.

13. Under the NEC working-space rules, the clear working space in front of electrical equipment must permit the equipment door or hinged panel to open to at least what angle?
    • 45 degrees
    • 60 degrees
    • 75 degrees
    • 90 degrees

    Correct answer: 90 degrees

    90 degrees is correct. NEC 110.26(A)(2) requires that the working width allow all equipment doors or hinged panels to open at least 90 degrees so that the equipment can be safely accessed and serviced. The smaller angles do not satisfy the code's requirement for full access to the working space.

14. On a set of electrical plans, a switch symbol marked with the subscript notation "S3" most directly tells the installer what about that device?
    • It is a three-way switch used to control a load from two locations
    • It is a single-pole switch rated for 3 amperes
    • It is a switch mounted three feet above the floor
    • It is a switch controlling three separate luminaires

    Correct answer: It is a three-way switch used to control a load from two locations

    It is a three-way switch used to control a load from two locations is correct. On electrical plan drawings, the subscript 3 on a switch symbol designates a three-way switch, which is installed in pairs to control a single load from two different points. The notation does not indicate an amperage rating, a mounting height, or the number of luminaires controlled.

15. Using the standard calculation method of Article 220, what is the general lighting load for a 2,400-square-foot dwelling unit before applying any demand factors?
    • 9,600 volt-amperes
    • 4,800 volt-amperes
    • 7,200 volt-amperes
    • 2,400 volt-amperes

    Correct answer: 7,200 volt-amperes

    7,200 volt-amperes is correct. Article 220 assigns a general lighting and general-use receptacle load of 3 volt-amperes per square foot for a dwelling, so 2,400 square feet multiplied by 3 equals 7,200 volt-amperes. Using 2 or 4 volt-amperes per square foot, or omitting the multiplier, produces the other figures.

16. When performing a standard dwelling service load calculation, what demand factor does Article 220 permit to be applied to the portion of the general lighting and general-use receptacle load that exceeds the first 3,000 volt-amperes, up to 120,000 volt-amperes?
    • 100 percent
    • 40 percent
    • 35 percent
    • 70 percent

    Correct answer: 35 percent

    35 percent is correct. The standard-method demand table for dwelling general lighting requires the first 3,000 volt-amperes at 100 percent and the remainder from 3,001 to 120,000 volt-amperes at 35 percent. The 100 percent figure applies only to that first portion, and the other percentages are not part of this lighting demand schedule.

17. In a standard-method dwelling service calculation, at what demand percentage must the two required small-appliance branch circuits and the laundry branch circuit be included before the general-lighting demand factors are applied?
    • 100 percent
    • 75 percent
    • 35 percent
    • 50 percent

    Correct answer: 100 percent

    100 percent is correct. The required small-appliance and laundry circuits are each counted at 1,500 volt-amperes and are added at full value to the general lighting load before the standard 3,000-volt-ampere/35-percent demand schedule is applied. Applying a reduced percentage to these circuits before combining them with lighting is not permitted under the standard method.

18. A dwelling has a calculated service load of 192 amperes at 240 volts, single phase. What is the minimum standard ampere rating of service-entrance equipment and overcurrent device that may be used for this dwelling?
    • 175 amperes
    • 200 amperes
    • 225 amperes
    • 150 amperes

    Correct answer: 200 amperes

    200 amperes is correct. Where the calculated load falls between standard overcurrent device sizes, the next higher standard size from the standard-ampere-ratings list must be selected, and 200 amperes is the next standard size above 192 amperes. A 175-ampere device would be below the calculated load, and a one-family dwelling service must be at least 100 amperes regardless.

19. Under the NEC, what is the minimum ampacity permitted for the ungrounded service-entrance conductors and disconnecting means supplying a one-family dwelling served by a 120/240-volt single-phase system?
    • 60 amperes
    • 100 amperes
    • 125 amperes
    • 150 amperes

    Correct answer: 100 amperes

    100 amperes is correct. The NEC establishes a minimum service rating of 100 amperes, three-wire, for a one-family dwelling, so the service-entrance conductors and disconnect must be rated at least 100 amperes. The 60-ampere minimum applies to other limited situations, and the higher values exceed the stated minimum.

20. For a dwelling service rated 200 amperes at 120/240 volts, the NEC dwelling service conductor table permits which copper conductor size for the ungrounded service-entrance conductors?
    • 4/0 AWG
    • 2/0 AWG
    • 3/0 AWG
    • 1/0 AWG

    Correct answer: 2/0 AWG

    2/0 AWG is correct. The NEC table for dwelling 120/240-volt single-phase service and feeder conductors allows 2/0 AWG copper for a 200-ampere service, recognizing the limited diversity of dwelling loads. The 4/0 and 3/0 copper sizes are larger than required, and 1/0 copper is rated for only a 150-ampere service.

21. When sizing service-entrance conductors, which NEC provision allows dwelling-unit service conductors to be smaller than the general ampacity table would otherwise require for the same ampere rating?
    • The 125 percent continuous-load rule
    • The grounding electrode conductor sizing table
    • The neutral demand reduction above 200 amperes
    • The dwelling services and feeders conductor table (the 83 percent allowance)

    Correct answer: The dwelling services and feeders conductor table (the 83 percent allowance)

    The dwelling services and feeders conductor table (the 83 percent allowance) is correct. The NEC provides a special table for 120/240-volt, single-phase dwelling services and main feeders that permits conductors sized at about 83 percent of the standard ampacity, reflecting dwelling load diversity. The continuous-load rule and the neutral demand reduction address different parts of a calculation, and the grounding electrode table sizes a different conductor entirely.

22. Service-entrance conductors must have an ampacity at least equal to what value when supplying a continuous load plus a noncontinuous load?
    • 100 percent of the continuous load plus 100 percent of the noncontinuous load
    • 125 percent of the continuous load plus 100 percent of the noncontinuous load
    • 125 percent of both the continuous and noncontinuous loads
    • 100 percent of the continuous load plus 125 percent of the noncontinuous load

    Correct answer: 125 percent of the continuous load plus 100 percent of the noncontinuous load

    125 percent of the continuous load plus 100 percent of the noncontinuous load is correct. Service conductors and their overcurrent protection must be sized for the noncontinuous load plus 125 percent of the continuous load, because continuous loads operate for three hours or more and require the added margin. Counting both loads at 100 percent omits the continuous-load factor, and applying 125 percent to the noncontinuous portion misplaces the multiplier.

23. A service is supplied by 3/0 AWG copper ungrounded service-entrance conductors. Using the NEC grounding electrode conductor table, what is the minimum size copper grounding electrode conductor required?
    • 8 AWG copper
    • 6 AWG copper
    • 4 AWG copper
    • 2 AWG copper

    Correct answer: 4 AWG copper

    4 AWG copper is correct. The grounding electrode conductor table sizes the conductor by the largest ungrounded service conductor; for service conductors larger than 2/0 through 3/0 AWG copper, a 4 AWG copper grounding electrode conductor is required. The smaller 6 and 8 AWG sizes correspond to smaller service conductors, and 2 AWG would be required only for larger service conductors.

24. What is the largest size copper grounding electrode conductor the NEC ever requires to be run to a made electrode such as a ground rod, regardless of service size?
    • 1/0 AWG copper
    • 4 AWG copper
    • 2 AWG copper
    • 6 AWG copper

    Correct answer: 6 AWG copper

    6 AWG copper is correct. The NEC states that the grounding electrode conductor connection to a rod, pipe, or plate electrode is not required to be larger than 6 AWG copper, because the earth-contact resistance of such electrodes limits the useful conductor size. Larger sizes are required only for conductors run to a concrete-encased electrode, ground ring, or as the main grounding electrode conductor based on service size.

25. Where a grounding electrode conductor is connected to a concrete-encased electrode, what is the maximum size copper conductor the NEC requires regardless of the size of the service-entrance conductors?
    • 4 AWG copper
    • 6 AWG copper
    • 2 AWG copper
    • 1/0 AWG copper

    Correct answer: 4 AWG copper

    4 AWG copper is correct. The NEC limits the portion of the grounding electrode conductor connected to a concrete-encased electrode to no larger than 4 AWG copper. The 6 AWG limit applies to rod, pipe, and plate electrodes, and the larger conductor sizes would be required only when the full grounding electrode conductor table dictates them for other electrode types.

26. A grounding electrode conductor that is the sole connection to a driven ground rod and is exposed but not subject to physical damage may be installed without a protective raceway if it is at least what size, and otherwise must be protected?
    • 8 AWG copper
    • 4 AWG copper
    • 6 AWG copper
    • 10 AWG copper

    Correct answer: 6 AWG copper

    6 AWG copper is correct. The NEC permits a 6 AWG copper or larger grounding electrode conductor that is free from exposure to physical damage to be run along the surface of the building without a raceway where it is securely fastened. Conductors smaller than 6 AWG must always be protected in a raceway or armor.

27. At service equipment, which conductor provides the connection that places the grounded service conductor and the equipment grounding terminal bar at the same potential?
    • The main bonding jumper
    • The grounding electrode conductor
    • The equipment grounding conductor of a branch circuit
    • The grounded circuit conductor of a feeder

    Correct answer: The main bonding jumper

    The main bonding jumper is correct. The main bonding jumper is the connection at the service that bonds the grounded (neutral) service conductor to the equipment grounding terminal and the enclosure, completing the ground-fault return path. The grounding electrode conductor connects to earth, while the listed circuit conductors carry normal or fault current rather than performing the service-point bond.

28. On the secondary side of a separately derived system such as a transformer, what is the name of the connection required between the grounded conductor and the equipment grounding conductor or supply-side bonding jumper?
    • The main bonding jumper
    • The neutral demand jumper
    • The grounding electrode conductor
    • The system bonding jumper

    Correct answer: The system bonding jumper

    The system bonding jumper is correct. For a separately derived system, the connection between the derived grounded conductor and the equipment grounding conductor is called the system bonding jumper, and it serves the same purpose as a main bonding jumper does at a service. The main bonding jumper is the service-point term, the grounding electrode conductor connects the system to earth, and the other option is not a recognized NEC term.

29. The main bonding jumper and system bonding jumper are required to be sized using which NEC table or rule?
    • The dwelling services and feeders conductor table
    • The equipment grounding conductor table based on the circuit overcurrent device
    • The conductor ampacity table at 75 degrees Celsius
    • The same table used to size the grounding electrode conductor

    Correct answer: The same table used to size the grounding electrode conductor

    The same table used to size the grounding electrode conductor is correct. The NEC requires main and system bonding jumpers to be sized in accordance with the grounding electrode conductor table, based on the size of the derived or service ungrounded conductors. The equipment grounding conductor table and ampacity tables are used for other conductors, and the dwelling table sizes ungrounded service conductors.

30. Where ungrounded supply conductors are larger than 1,100 kcmil copper, the main bonding jumper or supply-side bonding jumper must have a cross-sectional area not less than what fraction of the area of the largest ungrounded supply conductor?
    • 8 percent
    • 12.5 percent
    • 25 percent
    • 50 percent

    Correct answer: 12.5 percent

    12.5 percent is correct. When the ungrounded supply conductors exceed 1,100 kcmil copper or 1,750 kcmil aluminum, the NEC requires the bonding jumper to be at least 12 and a half percent of the area of the largest ungrounded conductor. The other percentages do not match this large-conductor bonding rule.

31. For a service supplied by 250 kcmil copper ungrounded conductors, the NEC requires the grounded service conductor to be sized using the grounding electrode conductor table but never smaller than what value when it also serves as the effective ground-fault return path?
    • The size given for the grounding electrode conductor based on the service conductors
    • 6 AWG copper in all cases
    • The full ampacity of the ungrounded conductors
    • One-third the size of the ungrounded conductors

    Correct answer: The size given for the grounding electrode conductor based on the service conductors

    The size given for the grounding electrode conductor based on the service conductors is correct. The grounded service conductor must be sized at least as large as the value from the grounding electrode conductor table for the given ungrounded service conductors, because it carries fault current back to the source. A fixed 6 AWG minimum, full ampacity, or a one-third rule does not describe this requirement.

32. When calculating the size of the grounded (neutral) service conductor, which NEC demand allowance may be applied to the portion of the neutral load that exceeds 200 amperes?
    • A 70 percent demand factor on the excess
    • A 35 percent demand factor on the excess
    • A 50 percent demand factor on the excess
    • No demand factor is permitted on the neutral

    Correct answer: A 70 percent demand factor on the excess

    A 70 percent demand factor on the excess is correct. The NEC permits the neutral load to be calculated at 100 percent for the first 200 amperes and at 70 percent for the portion above 200 amperes, recognizing reduced diversity on the grounded conductor. The 35 percent factor applies to dwelling lighting, and stating that no reduction is allowed contradicts the neutral demand provision.

33. Under Article 215, feeder conductors that supply a combination of continuous and noncontinuous loads must have an allowable ampacity, before applying any adjustment or correction factors, of not less than what value?
    • The noncontinuous load plus 100 percent of the continuous load
    • The noncontinuous load plus 125 percent of the continuous load
    • 125 percent of the combined continuous and noncontinuous load
    • 100 percent of the combined continuous and noncontinuous load

    Correct answer: The noncontinuous load plus 125 percent of the continuous load

    A feeder ampacity of the noncontinuous load plus 125 percent of the continuous load is required. Section 215.2(A)(1) sets this as the minimum feeder conductor size before any temperature or conduit-fill adjustment factors are applied, matching the overcurrent-device sizing requirement so the conductor is not loaded beyond a safe steady-state level for loads energized three hours or more. Taking only 100 percent of the continuous load ignores the sustained heating effect. Applying 125 percent to the entire combined load over-sizes the noncontinuous portion unnecessarily.

34. A feeder supplies a noncontinuous load of 60 amperes and a continuous load of 80 amperes. What minimum feeder conductor ampacity does Article 215 require before any temperature or conduit-fill adjustments are applied?
    • 140 amperes
    • 175 amperes
    • 160 amperes
    • 165 amperes

    Correct answer: 160 amperes

    A minimum feeder ampacity of 160 amperes is correct. Section 215.2(A)(1) requires the noncontinuous load at 100 percent plus the continuous load at 125 percent: $60\,\text{A} + (80\,\text{A} \times 1.25) = 60 + 100 = 160\,\text{A}$. Choosing 140 amperes counts the continuous load at only 100 percent, ignoring the required 25 percent adder. Choosing 175 amperes incorrectly multiplies the full 140-ampere combined load by 1.25.

35. When a feeder supplies fixed electric space-heating equipment along with other loads, how does Article 215 require the feeder to be sized with respect to that heating load?
    • The heating load may be omitted if the other loads exceed it
    • The heating load is taken at 80 percent because it is intermittent
    • The feeder is sized only for the largest single appliance on it
    • Fixed electric space heating is treated as a continuous load

    Correct answer: Fixed electric space heating is treated as a continuous load

    Fixed electric space-heating equipment is classified as a continuous load under Section 424.3(B), which governs branch-circuit sizing for this equipment. For feeder and service load calculations, Section 220.51 requires the full connected heating load to be included at 100 percent of its total connected load - no demand factor reduction applies. Working through Article 215, the feeder must therefore carry the heating load in full and cannot omit it, reduce it to 80 percent as if it were intermittent, or count only the largest appliance. The heating load is never reduced away from the feeder calculation.

36. Article 220 permits a demand factor to be applied to four or more household electric clothes dryers supplied by a feeder. What is the primary purpose of applying this demand factor when sizing the feeder?
    • To account for the fact that not all dryers operate at full load simultaneously
    • To increase the feeder size for future expansion of the laundry area
    • To convert the dryer nameplate rating from watts to volt-amperes
    • To compensate for voltage drop on long feeder runs

    Correct answer: To account for the fact that not all dryers operate at full load simultaneously

    Applying the demand factor from Table 220.54 accounts for the statistical reality that not all dryers in a building run at their full rated load at the same moment. The table allows a feeder serving four or more dryers to be sized below the sum of all nameplate ratings because simultaneous full operation is unlikely, producing an economical yet safe feeder design. Demand factors do not add spare capacity for future expansion, do not change units of measure between watts and volt-amperes, and are unrelated to compensating for voltage drop on long conductor runs.

37. A feeder serves the general lighting load of a dwelling with a calculated general lighting and general-use receptacle load of 8,000 volt-amperes. Applying the standard-method demand factors of Article 220 (first 3,000 volt-amperes at 100 percent and the remainder at 35 percent), what is the demand load on this feeder for that lighting?
    • 8,000 volt-amperes
    • 4,750 volt-amperes
    • 5,000 volt-amperes
    • 2,800 volt-amperes

    Correct answer: 4,750 volt-amperes

    A demand load of 4,750 volt-amperes is correct. Under Table 220.45, the first 3,000 volt-amperes of the dwelling general lighting load is taken at 100 percent, which equals 3,000 volt-amperes. The remaining 5,000 volt-amperes (8,000 minus 3,000) is taken at 35 percent, which equals 1,750 volt-amperes. Adding $3{,}000 + 1{,}750 = 4{,}750$ volt-amperes. Using 8,000 volt-amperes ignores the demand factor entirely. The value 5,000 volt-amperes would result from incorrectly applying 35 percent to the full load. The value 2,800 volt-amperes would result from applying 35 percent to the entire 8,000-volt-ampere load.

38. Two feeders supply identical 30,000-volt-ampere connected lighting loads. Feeder A serves a warehouse where Table 220.42 allows a demand factor on the load above the first 12,500 volt-amperes, while Feeder B serves an occupancy where no demand factor is permitted. What does this difference reveal about how Article 220 assigns lighting demand factors?
    • Demand factors depend only on the total connected load, not the occupancy
    • Demand factors are applied to every occupancy at the same fixed percentage
    • Demand factors increase the feeder load for occupancies with continuous use
    • Demand factors vary by occupancy type based on expected diversity of use

    Correct answer: Demand factors vary by occupancy type based on expected diversity of use

    Demand factors vary by occupancy type based on expected diversity of use. Table 220.42 assigns different lighting demand factors to different occupancies because some building types, such as storage warehouses, seldom have all lighting energized simultaneously, while occupancies such as hospitals or retail stores operate lighting more continuously and receive little or no reduction. Storage warehouses receive a demand factor reduction on the load above the first 12,500 volt-amperes, reflecting the diversity of their lighting use. Demand factors are therefore not based on connected load magnitude alone, are not a uniform fixed percentage for all occupancy types, and never increase the calculated feeder load.

39. Where a feeder carries the calculated load of two or more subpanels, Article 215 requires that the feeder overcurrent protection and conductor ampacity be coordinated in what way?
    • The feeder may be protected at twice the conductor ampacity for motor loads
    • The feeder OCPD rating need not relate to the downstream panel ratings
    • The feeder conductor ampacity must be at least the calculated load it supplies
    • The feeder is sized only to the rating of the largest downstream panel

    Correct answer: The feeder conductor ampacity must be at least the calculated load it supplies

    The feeder conductor ampacity must be at least the calculated load it supplies. Section 215.2(A) requires that feeder conductors have an ampacity not less than the load as calculated in Parts III, IV, and V of Article 220. When a feeder supplies two or more subpanels, the conductor must carry the combined calculated demand of all panels it feeds, and the overcurrent device is generally sized to protect that conductor. Limiting the feeder to the rating of the largest downstream panel ignores the aggregate load of all panels served. The feeder OCPD must be coordinated with the conductor ampacity. The double-ampacity allowance is specific to motor loads under Article 430 and does not apply to general-purpose feeders.

40. Electrical metallic tubing (EMT) is identified in the NEC under which article governing its use, installation, and construction as a wiring method?
    • Article 358
    • Article 250
    • Article 314
    • Article 220

    Correct answer: Article 358

    Article 358 is correct. Electrical metallic tubing is the subject of Article 358, which covers its uses permitted, uses not permitted, support, bends, and fittings as a recognized Chapter 3 wiring method. Article 250 covers grounding and bonding, Article 314 covers boxes and conduit bodies, and Article 220 covers load calculations, none of which is the EMT article.

41. According to the support requirements for electrical metallic tubing, EMT must be securely fastened in place within how many inches of each outlet box, junction box, device box, or other tubing termination?
    • 12 inches
    • 36 inches
    • 18 inches
    • 3 inches

    Correct answer: 36 inches

    36 inches is correct. Section 358.30 requires EMT to be securely fastened within 3 feet (36 inches) of each box, cabinet, conduit body, or other tubing termination, and then supported at intervals not exceeding 10 feet. The 12-inch and 18-inch figures understate the allowed termination distance, and 3 inches is far more restrictive than the code requires.

42. A run of electrical metallic tubing between two pull points must not contain more than how many degrees of total bends, including offsets, before a pull box or conduit body is required?
    • 180 degrees
    • 270 degrees
    • 360 degrees
    • 90 degrees

    Correct answer: 360 degrees

    360 degrees is correct. Section 358.26 limits a run of EMT between pull points to no more than the equivalent of four quarter bends, totaling 360 degrees, to keep conductor pulling tension manageable. The smaller totals would unnecessarily restrict the run, and exceeding 360 degrees would risk damaging conductors during installation.

43. Type NM (nonmetallic-sheathed) cable is permitted as a wiring method primarily in which type of location?
    • Direct burial in the earth
    • Embedded in poured concrete
    • Wet locations such as underground raceways
    • Normally dry, protected, and concealed or exposed indoor locations

    Correct answer: Normally dry, protected, and concealed or exposed indoor locations

    Normally dry, protected, and concealed or exposed indoor locations is correct. Article 334 permits Type NM cable for both exposed and concealed work in normally dry locations of permitted occupancies, such as one- and two-family dwellings. The NEC prohibits NM cable in wet or damp locations, embedded in concrete, or for direct burial, all of which require a different wiring method.

44. How must Type NM cable be secured when run across the face of framing members or otherwise installed exposed, with respect to fastening intervals?
    • Secured at intervals not exceeding 4.5 feet and within 12 inches of each box
    • Secured only at each end of the run
    • Secured at intervals not exceeding 10 feet
    • Stapled only where it passes through a stud

    Correct answer: Secured at intervals not exceeding 4.5 feet and within 12 inches of each box

    Secured at intervals not exceeding 4.5 feet and within 12 inches of each box is correct. Section 334.30 requires Type NM cable to be supported and secured by staples, straps, or similar fittings at intervals not exceeding 4.5 feet and within 12 inches of every outlet box, junction box, cabinet, or fitting. Securing only at the ends, at 10-foot intervals, or only at studs does not meet the NM cable support rule.

45. For conductors all of the same size and insulation type, what is the maximum percentage of the cross-sectional area of a conduit that may be filled when three or more conductors are installed?
    • 31 percent
    • 40 percent
    • 53 percent
    • 60 percent

    Correct answer: 40 percent

    40 percent is correct. Chapter 9, Table 1 limits raceway fill to 40 percent of the conduit's interior cross-sectional area when three or more conductors are installed. The 53 percent figure applies to a single conductor, 31 percent applies to exactly two conductors, and 60 percent exceeds any permitted general fill value.

46. When only a single conductor is installed in a conduit or tubing, what is the maximum percentage of the raceway's cross-sectional area that the conductor may occupy?
    • 40 percent
    • 31 percent
    • 53 percent
    • 60 percent

    Correct answer: 53 percent

    53 percent is correct. Chapter 9, Table 1 permits a single conductor to fill up to 53 percent of the raceway's interior cross-sectional area. The 40 percent value applies to three or more conductors, 31 percent applies to two conductors, and 60 percent is not a recognized fill percentage.

47. When exactly two conductors are pulled into a conduit, the NEC limits the raceway fill to what maximum percentage of the conduit's cross-sectional area?
    • 53 percent
    • 40 percent
    • 25 percent
    • 31 percent

    Correct answer: 31 percent

    31 percent is correct. Chapter 9, Table 1 sets the maximum fill at 31 percent of the conduit's interior cross-sectional area when exactly two conductors are installed, a more restrictive value chosen to ease jamming of two conductors. The 53 percent figure is for a single conductor, 40 percent is for three or more, and 25 percent is not a code fill value.

48. In a standard outlet box, what volume allowance in cubic inches must be assigned for each 14 AWG insulated conductor when performing a box-fill calculation?
    • 2.00 cubic inches
    • 1.50 cubic inches
    • 2.25 cubic inches
    • 2.50 cubic inches

    Correct answer: 2.00 cubic inches

    2.00 cubic inches is correct. Table 314.16(B) assigns a free space volume of 2.00 cubic inches for each 14 AWG conductor in a box-fill calculation. A 12 AWG conductor is assigned 2.25 cubic inches and a 10 AWG conductor 2.50 cubic inches, while 1.50 cubic inches is not the value for 14 AWG.

49. When counting conductors for a box-fill calculation, how are all of the equipment grounding conductors entering a box counted, regardless of how many there are?
    • Each grounding conductor counts as one separate conductor
    • All grounding conductors together count as a single conductor volume allowance
    • Grounding conductors are not counted at all
    • Grounding conductors count double the largest conductor volume

    Correct answer: All grounding conductors together count as a single conductor volume allowance

    All grounding conductors together count as a single conductor volume allowance is correct. Section 314.16(B)(5) requires that all equipment grounding conductors in a box be counted as a single conductor volume based on the largest grounding conductor present. Counting each one separately, omitting them, or doubling them all misstates the box-fill rule.

50. In a box-fill calculation, how is a single device such as a switch or receptacle mounted on a yoke counted toward the total volume?
    • It is not counted because it is not a conductor
    • It counts as a single conductor based on the largest conductor connected to it
    • It counts as two conductors based on the largest conductor connected to the device
    • It counts as one conductor for each terminal screw

    Correct answer: It counts as two conductors based on the largest conductor connected to the device

    It counts as two conductors based on the largest conductor connected to the device is correct. Section 314.16(B)(4) requires each yoke or strap containing a device such as a switch or receptacle to be counted as two conductors based on the largest conductor connected to that device. The device is never ignored, counted as one, or counted by terminal screws under the box-fill rules.

51. A device box contains five 12 AWG conductors and one duplex receptacle, with all equipment grounding conductors of the same 12 AWG size present. Using 2.25 cubic inches per 12 AWG conductor, what minimum box volume in cubic inches is required?
    • 11.25 cubic inches
    • 13.50 cubic inches
    • 15.75 cubic inches
    • 18.00 cubic inches

    Correct answer: 18.00 cubic inches

    18.00 cubic inches is correct. The five current-carrying conductors count as 5, the receptacle yoke counts as 2, and all grounding conductors together count as 1, for a total of 8 conductor allowances; $8 \times 2.25 = 18.00$ cubic inches. Omitting the device or grounding allowance yields the lower figures, which understate the required volume.

52. For sizing a pull box or junction box containing conductors 4 AWG or larger in a straight pull, the NEC requires the length of the box to be not less than how many times the trade diameter of the largest raceway?
    • 8 times
    • 6 times
    • 12 times
    • 4 times

    Correct answer: 8 times

    8 times is correct. Section 314.28(A)(1) requires that for straight pulls, the length of the box be at least 8 times the trade diameter of the largest raceway. The 6-times factor applies to angle and U pulls between raceway entries, while 12 and 4 times are not the straight-pull multiplier.

53. For angle or U pulls in a junction box containing conductors 4 AWG or larger, the distance between each raceway entry and the opposite wall of the box must be at least how many times the trade diameter of the largest raceway?
    • 8 times
    • 6 times
    • 4 times
    • 10 times

    Correct answer: 6 times

    6 times is correct. Section 314.28(A)(2) requires that for angle or U pulls, the distance from each raceway entry to the opposite wall be at least 6 times the trade diameter of the largest raceway, plus the diameters of any additional raceways on the same wall. The 8-times factor is for straight pulls, and 4 and 10 times are not the angle-pull multipliers.

54. A junction box is installed for a straight pull where the largest raceway entering is 3-inch trade size. What is the minimum required length of the box in the direction of the pull?
    • 18 inches
    • 12 inches
    • 24 inches
    • 30 inches

    Correct answer: 24 inches

    24 inches is correct. For a straight pull, Section 314.28(A)(1) requires the box length to be at least 8 times the trade diameter of the largest raceway, so $8 \times 3 = 24$ inches. Using a 6-times factor gives 18 inches and a 4-times factor gives 12 inches, neither of which satisfies the straight-pull requirement.

55. Under Table 300.5, what is the minimum cover (burial depth) required for direct-buried unprotected UF cable or conductors rated 600 volts or less installed under a residential driveway of a one-family dwelling?
    • 6 inches
    • 12 inches
    • 24 inches
    • 18 inches

    Correct answer: 18 inches

    18 inches is correct. Table 300.5 requires 18 inches of cover for direct-buried cables and conductors under a one- and two-family dwelling driveway. The 24-inch figure is the general minimum for direct burial in open ground, 12 inches applies under residential driveways only for circuits limited to a special low-voltage column, and 6 inches is far below any direct-burial requirement.

56. What is the general minimum cover in inches required by Table 300.5 for direct-buried cables or conductors rated 0 to 600 volts installed in a trench in earth with no other protection?
    • 24 inches
    • 18 inches
    • 12 inches
    • 36 inches

    Correct answer: 24 inches

    24 inches is correct. Table 300.5 requires a minimum cover of 24 inches for direct-buried conductors and cables rated 0 to 600 volts in the general burial location column. The 18-inch value applies to rigid metal conduit and intermediate metal conduit, 12 inches applies to certain low-voltage circuits, and 36 inches is deeper than the general direct-burial requirement.

57. Under Table 300.5, what minimum cover is required for circuits installed in rigid metal conduit (RMC) or intermediate metal conduit (IMC) buried in earth at 600 volts or less?
    • 24 inches
    • 6 inches
    • 18 inches
    • 12 inches

    Correct answer: 6 inches

    6 inches is correct. Table 300.5 permits a reduced minimum cover of 6 inches for rigid metal conduit and intermediate metal conduit because these raceways provide robust physical protection for the enclosed conductors. The 24-inch figure is for direct burial, 18 inches applies under driveways, and 12 inches applies to certain residential branch circuits, none of which is the RMC/IMC value.

58. Which of the following is recognized by Section 250.118 as an acceptable type of equipment grounding conductor?
    • An isolated dedicated grounding rod at each receptacle
    • The grounded neutral conductor of the branch circuit
    • A bare copper conductor that is part of the wiring method or run separately
    • A plastic raceway alone with no internal grounding means

    Correct answer: A bare copper conductor that is part of the wiring method or run separately

    A bare copper conductor that is part of the wiring method or run separately is correct. Section 250.118 lists a copper or other corrosion-resistant conductor, solid or stranded, insulated or bare, among the recognized equipment grounding conductor types. The grounded neutral is not an equipment grounding conductor, a separate rod at each receptacle is not an effective fault path, and a plastic raceway alone provides no grounding.

59. What is the primary function of the equipment grounding conductor in a branch-circuit wiring method?
    • To carry normal load current back to the source
    • To reduce voltage drop on long circuits
    • To serve as a spare ungrounded conductor
    • To provide a low-impedance path for fault current so the overcurrent device operates

    Correct answer: To provide a low-impedance path for fault current so the overcurrent device operates

    Providing a low-impedance path for fault current so the overcurrent device operates is correct. The equipment grounding conductor connects normally non-current-carrying metal parts together and back to the source so that a ground fault produces enough current to quickly open the breaker or fuse. It does not carry normal load current, is not a spare ungrounded conductor, and is not installed to address voltage drop.

60. Using Table 250.122, what is the minimum size copper equipment grounding conductor required for a circuit protected by a 60-ampere overcurrent device?
    • 10 AWG copper
    • 12 AWG copper
    • 8 AWG copper
    • 14 AWG copper

    Correct answer: 10 AWG copper

    10 AWG copper is correct. Table 250.122 requires a 10 AWG copper equipment grounding conductor where the overcurrent device protecting the circuit is rated over 20 amperes through 60 amperes. A 12 AWG copper conductor serves circuits up to 20 amperes, 8 AWG is required for circuits over 100 amperes through 200 amperes, and 14 AWG is not listed for a 60-ampere circuit.

61. According to Table 250.122, what is the minimum size copper equipment grounding conductor for a circuit protected by a 100-ampere overcurrent device?
    • 10 AWG copper
    • 8 AWG copper
    • 6 AWG copper
    • 4 AWG copper

    Correct answer: 8 AWG copper

    8 AWG copper is correct. Table 250.122 requires an 8 AWG copper equipment grounding conductor where the overcurrent device rating is over 60 amperes through 100 amperes. A 10 AWG conductor covers circuits up to 60 amperes, 6 AWG is required over 100 through 200 amperes, and 4 AWG covers larger ratings.

62. When ungrounded conductors are increased in size to compensate for voltage drop, how does Section 250.122 require the equipment grounding conductor to be treated?
    • It remains sized only by the overcurrent device rating
    • It may be omitted because larger conductors carry less fault current
    • It must be increased proportionally to the increase in the ungrounded conductors
    • It must be doubled in size regardless of the increase

    Correct answer: It must be increased proportionally to the increase in the ungrounded conductors

    It must be increased proportionally to the increase in the ungrounded conductors is correct. Section 250.122(B) requires that where ungrounded conductors are upsized for any reason such as voltage drop, the equipment grounding conductor must be increased in size proportionally based on circular mil area. The grounding conductor cannot stay at the table minimum, cannot be omitted, and is not simply doubled.

63. Which wiring method article of the NEC covers the general requirements that apply to all wiring methods, such as protection against physical damage and securing of conductors?
    • Article 110
    • Article 310
    • Article 408
    • Article 300

    Correct answer: Article 300

    Article 300 is correct. Article 300 contains the general requirements for wiring methods, including protection against physical damage, securing and supporting, and installation in raceways, applying broadly across Chapter 3. Article 310 covers conductors for general wiring, Article 408 covers switchboards and panelboards, and Article 110 covers general installation requirements rather than wiring-method specifics.

64. Where a cable or raceway-type wiring method is installed through bored holes in wood framing members, the NEC requires the edge of the hole to be at least how far from the nearest edge of the wood member, or else protected by a steel plate?
    • 1.25 inches
    • 1 inch
    • 0.75 inch
    • 2 inches

    Correct answer: 1.25 inches

    1.25 inches is correct. Section 300.4(A)(1) requires bored holes in wood framing to be located so the nearest edge of the hole is at least 1.25 inches from the nearest edge of the member; if that distance cannot be maintained, a steel plate at least 1/16 inch thick must protect the cable or raceway from screws and nails. The other distances do not match this physical-protection requirement.

65. A box-fill calculation includes one or more internal cable clamps. How are all of the clamps inside a box counted toward the box volume?
    • Each clamp counts as one conductor volume
    • All clamps together count as a single conductor based on the largest conductor in the box
    • Clamps are not counted in box fill
    • Each clamp counts as two conductors

    Correct answer: All clamps together count as a single conductor based on the largest conductor in the box

    All clamps together count as a single conductor based on the largest conductor in the box is correct. Section 314.16(B)(2) requires that where one or more internal cable clamps are present, a single volume allowance based on the largest conductor in the box be made for all clamps collectively. Counting each clamp separately, omitting clamps entirely, or doubling them misstates the clamp-fill rule.

66. Where Type NM cable passes through a factory or field punched, cut, or drilled opening in metal framing members, what protection does the NEC require?
    • No protection because metal framing is grounded
    • A coating of paint on the cable sheath
    • A listed bushing or grommet covering all metal edges of the opening
    • A separate equipment grounding conductor only

    Correct answer: A listed bushing or grommet covering all metal edges of the opening

    A listed bushing or grommet covering all metal edges of the opening is correct. Section 300.4(B)(1) requires Type NM cable run through openings in metal framing members to be protected by listed bushings or grommets that securely cover all metal edges, preventing abrasion of the cable. Metal framing being grounded does not protect the sheath, paint is not a recognized method, and an equipment grounding conductor does not address physical abrasion.

67. A conduit run will contain four 8 AWG THHN conductors of the same size. To determine the minimum conduit trade size, which value must be compared against the conduit's permitted fill area?
    • The total conductor area against 60 percent of the conduit area
    • The single largest conductor against 53 percent of the conduit area
    • The total conductor area against 31 percent of the conduit area
    • The total cross-sectional area of the four conductors against 40 percent of the conduit area

    Correct answer: The total cross-sectional area of the four conductors against 40 percent of the conduit area

    The total cross-sectional area of the four conductors against 40 percent of the conduit area is correct. Chapter 9, Table 1 limits three or more conductors to 40 percent fill, so the summed conductor areas from Chapter 9, Table 5 must fit within 40 percent of the conduit's interior area. The 53 percent and 31 percent limits apply to one and two conductors respectively, and 60 percent is not a valid fill percentage.

68. Why does the NEC assign a smaller percentage fill limit for two conductors in a raceway than for three or more conductors?
    • Because two round conductors are more likely to jam against each other when pulled
    • Because two conductors generate more heat than three
    • Because two conductors require more grounding space
    • Because two conductors carry more current than three

    Correct answer: Because two round conductors are more likely to jam against each other when pulled

    Because two round conductors are more likely to jam against each other when pulled is correct. The 31 percent fill limit for exactly two conductors, lower than the 40 percent for three or more, addresses the geometric tendency of two round conductors to wedge or jam side by side in a raceway during pulling. Two conductors do not generate more heat, need more grounding space, or carry more current than three.

69. A pull box has two 2-inch raceways entering one wall and the conductors make a 90-degree angle pull to an adjacent wall. What is the minimum distance from the raceway entries to the opposite wall, based on the angle-pull rule?
    • 8 inches
    • 12 inches
    • 16 inches
    • 6 inches

    Correct answer: 12 inches

    12 inches is correct. For an angle pull, Section 314.28(A)(2) requires the distance from a raceway entry to the opposite wall to be at least 6 times the trade diameter of the largest raceway, so $6 \times 2 = 12$ inches. Using an 8-times straight-pull factor or smaller multipliers does not satisfy the angle-pull requirement.

70. Under Table 250.122, what minimum size copper equipment grounding conductor is required for a 20-ampere branch circuit?
    • 14 AWG copper
    • 10 AWG copper
    • 12 AWG copper
    • 16 AWG copper

    Correct answer: 12 AWG copper

    12 AWG copper is correct. Table 250.122 requires a 12 AWG copper equipment grounding conductor for overcurrent devices rated up to and including 20 amperes. A 14 AWG copper conductor is only adequate for circuits up to 15 amperes, 10 AWG is required for larger circuits up to 60 amperes, and 16 AWG is not a recognized branch-circuit grounding size.

71. For electrical metallic tubing to be cut, what installation practice does Article 358 require regarding the cut ends of the tubing?
    • Cut ends must be left sharp to grip the coupling
    • Cut ends must be flared outward
    • Cut ends must be threaded before coupling
    • Cut ends must be reamed to remove burrs and rough edges

    Correct answer: Cut ends must be reamed to remove burrs and rough edges

    Cut ends must be reamed to remove burrs and rough edges is correct. Section 358.28 requires that all cut ends of EMT be reamed or otherwise finished to remove rough edges and burrs that could damage conductor insulation during pulling. EMT is not threaded, is not flared, and leaving sharp edges would risk insulation damage rather than improve the connection.

72. What is the maximum support spacing the NEC permits for properly installed electrical metallic tubing along a horizontal run away from boxes and terminations?
    • 10 feet
    • 6 feet
    • 4.5 feet
    • 8 feet

    Correct answer: 10 feet

    10 feet is correct. Section 358.30 requires EMT to be supported at least every 10 feet along the run, after the initial fastening within 3 feet of each box or termination. The 4.5-foot interval applies to Type NM cable, while 6 and 8 feet are not the EMT support spacing.

73. Type NM cable installed in an unfinished basement, where the cable is smaller than two 6 AWG or three 8 AWG conductors, must be installed in what manner across the bottom of floor joists?
    • Run on the bottom of the joists secured every 10 feet
    • Run through bored holes in the joists or on a running board
    • Stapled flat to the underside of the subfloor
    • Left loose between joists without support

    Correct answer: Run through bored holes in the joists or on a running board

    Run through bored holes in the joists or on a running board is correct. Section 334.15(C) requires smaller Type NM cables in an unfinished basement to be run through bored holes in joists or on running boards to protect them from physical damage. Running cable across the bottom of joists, loose, or merely stapled to the subfloor does not provide the required protection for these smaller cables.

74. During a conduit fill calculation, where the total number of conductors and their sizes are known, which combination of NEC tables is used to find conductor cross-sectional areas and the permitted conduit fill?
    • Table 310.16 and Table 250.122
    • Table 314.16 and Table 300.5
    • Chapter 9 Table 5 for conductor areas and Chapter 9 Table 4 for conduit areas
    • Table 220.42 and Table 430.250

    Correct answer: Chapter 9 Table 5 for conductor areas and Chapter 9 Table 4 for conduit areas

    Chapter 9 Table 5 for conductor areas and Chapter 9 Table 4 for conduit areas is correct. Conduit fill calculations use Chapter 9, Table 5 to obtain the cross-sectional area of each insulated conductor and Chapter 9, Table 4 to find the permitted fill area of each raceway type and size. Table 310.16 gives ampacity, Table 314.16 covers box fill, Table 250.122 sizes grounding conductors, and the load-calculation tables are unrelated to conduit fill.

75. A 4-inch square box that is 1.5 inches deep has a marked volume of 21.0 cubic inches. Using 2.25 cubic inches per 12 AWG conductor, what is the maximum number of 12 AWG conductors permitted in this box if no devices, clamps, or grounding allowances apply?
    • 8 conductors
    • 7 conductors
    • 10 conductors
    • 9 conductors

    Correct answer: 9 conductors

    9 conductors is correct. Dividing the box volume by the per-conductor allowance, $\frac{21.0}{2.25} = 9.33$, is rounded down to 9 whole conductors. Allowing 10 would exceed the box volume, and 8 or 7 would understate the capacity of this box.

76. A junction box has a 3-inch raceway and a 2-inch raceway entering the same wall in a straight pull configuration. What is the minimum required length of the box in the direction of the pull, based on the largest raceway?
    • 24 inches
    • 18 inches
    • 16 inches
    • 20 inches

    Correct answer: 24 inches

    24 inches is correct. For a straight pull, Section 314.28(A)(1) bases the minimum box length on 8 times the trade diameter of the largest raceway, and the largest here is 3 inches, so $8 \times 3 = 24$ inches. The smaller raceway does not increase a straight-pull length, and the lower values would not satisfy the largest-raceway requirement.

77. In addition to the minimum cover values, what does Table 300.5 generally require to be placed above direct-buried conductors and cables to warn of their presence in a trench?
    • A layer of sand only
    • A warning ribbon placed in the trench above underground installations
    • A continuous metal grounding grid
    • A concrete cap regardless of depth

    Correct answer: A warning ribbon placed in the trench above underground installations

    A warning ribbon placed in the trench above underground installations is correct. The notes to Table 300.5 require a warning ribbon to be placed in the trench at least 12 inches above underground installations so that future excavation reveals the warning before reaching the conductors. Sand bedding, a grounding grid, and a concrete cap are not the general warning requirement, though supplemental protection is required in specific cases.

78. A feeder is installed where the ungrounded conductors are protected by a 200-ampere overcurrent device. Using Table 250.122, what is the minimum size copper equipment grounding conductor?
    • 8 AWG copper
    • 4 AWG copper
    • 6 AWG copper
    • 10 AWG copper

    Correct answer: 6 AWG copper

    6 AWG copper is correct. Table 250.122 requires a 6 AWG copper equipment grounding conductor where the overcurrent device rating is over 100 amperes through 200 amperes. An 8 AWG conductor covers up to 100 amperes, 4 AWG is required over 200 through 300 amperes, and 10 AWG covers only up to 60 amperes.

79. Why does the NEC limit the total bends between pull points in a conduit run to 360 degrees?
    • To prevent the conduit from becoming a current-carrying path
    • To keep the conduit fill below 40 percent
    • To reduce the weight of the installed raceway
    • To limit conductor pulling tension and the risk of insulation damage

    Correct answer: To limit conductor pulling tension and the risk of insulation damage

    To limit conductor pulling tension and the risk of insulation damage is correct. The 360-degree limit on bends between pull points keeps the friction and tension during conductor pulling within safe levels so that insulation is not stripped or damaged. The bend limit is unrelated to making the conduit a current path, reducing raceway weight, or controlling the percentage fill, which is governed separately.

80. A run of electrical metallic tubing is installed in a location subject to severe physical damage. What does Article 358 indicate about using EMT in such a location?
    • EMT is not permitted where subject to severe physical damage
    • EMT may be used but must be supported every 3 feet
    • EMT is always permitted in any physical-damage location
    • EMT may be used only if filled to no more than 31 percent

    Correct answer: EMT is not permitted where subject to severe physical damage

    EMT is not permitted where subject to severe physical damage is correct. Section 358.12 lists locations subject to severe physical damage among the uses not permitted for electrical metallic tubing, because the thin-wall tubing offers limited mechanical protection. EMT is therefore not allowed in those areas regardless of support spacing or conduit fill, and a more robust raceway such as rigid metal conduit is used instead.

81. When a single conductor of a circuit is installed in a separate metal raceway, why must all conductors of that circuit be grouped together in the same raceway under the wiring-methods rules?
    • To reduce the conduit fill percentage
    • To prevent induced heating from circulating currents in the metal raceway
    • To make the conductors easier to identify
    • To allow a smaller equipment grounding conductor

    Correct answer: To prevent induced heating from circulating currents in the metal raceway

    Preventing induced heating from circulating currents in the metal raceway is correct. Section 300.3(B) requires all conductors of the same circuit, including the grounded and equipment grounding conductors, to be run together so their magnetic fields cancel; separating a single conductor into its own ferrous raceway induces circulating currents that overheat the metal. Reducing fill, easing identification, and grounding-conductor size are not the reason for keeping circuit conductors together.

82. What is the primary purpose of the overcurrent protective device that protects a branch-circuit conductor under Article 240?
    • To correct the power factor of the connected load
    • To reduce voltage drop along the conductor
    • To limit the available short-circuit current of the utility
    • To protect the conductor and equipment from the effects of excessive current

    Correct answer: To protect the conductor and equipment from the effects of excessive current

    Protecting the conductor and equipment from the effects of excessive current is correct. Article 240 requires overcurrent devices to open the circuit when current reaches a value that would cause a dangerous temperature in the conductor or its insulation, covering both overloads and faults. Overcurrent devices do not correct power factor, reduce voltage drop, or limit the utility's available fault current.

83. A continuous load draws 35 amperes. Where the overcurrent device and its assembly are not listed for operation at 100 percent of their rating, what minimum standard overcurrent device rating does Article 240 require for this circuit?
    • 35 amperes
    • 40 amperes
    • 45 amperes
    • 50 amperes

    Correct answer: 45 amperes

    45 amperes is correct. For a continuous load, the overcurrent device must be rated at not less than 125 percent of the load, so $35\,\text{A} \times 1.25 = 43.75\,\text{A}$, which is rounded up to the next standard size of 45 amperes from Section 240.6(A). A 35- or 40-ampere device is below the required minimum, and 50 amperes is the next standard size beyond 45 and is larger than necessary.

84. Where are overcurrent devices required by Section 240.24 to be located so that they are readily accessible?
    • Only within 5 feet of the service point
    • At a height of exactly 4 feet above the floor in all cases
    • So that the center of the operating handle is not more than 6 feet 7 inches above the floor or working platform
    • Inside a locked room accessible only to qualified persons

    Correct answer: So that the center of the operating handle is not more than 6 feet 7 inches above the floor or working platform

    Locating the device so the center of the operating handle is not more than 6 feet 7 inches above the floor or working platform is correct. Section 240.24(A) requires overcurrent devices to be readily accessible with the handle's center no higher than 2.0 meters (6 feet 7 inches), unless a specified exception applies. A fixed 4-foot height, a 5-foot service limit, and locking the room behind restricted access do not state the general accessibility height rule.

85. Section 240.4(D) places small-conductor restrictions on overcurrent protection regardless of ampacity. What is the maximum overcurrent device rating generally permitted to protect a 14 AWG copper conductor?
    • 20 amperes
    • 15 amperes
    • 25 amperes
    • 30 amperes

    Correct answer: 15 amperes

    15 amperes is correct. The small-conductor rule in Section 240.4(D) limits overcurrent protection for 14 AWG copper to a maximum of 15 amperes even though its ampacity table value may appear higher. A 20-ampere device is the limit for 12 AWG copper, 30 amperes is the limit for 10 AWG copper, and 25 amperes is not the assigned small-conductor limit for 14 AWG.

86. A fuse or circuit breaker is connected so that the conductor it protects has an ampacity that does not correspond to a standard device rating. Under Section 240.4(B), when may the next higher standard overcurrent device rating be used?
    • Whenever the load is continuous
    • Only for motor branch circuits
    • Never; the device must always be smaller than the conductor ampacity
    • When the conductor ampacity does not correspond to a standard rating, the next higher standard size of 800 amperes or less may be used if conditions are met

    Correct answer: When the conductor ampacity does not correspond to a standard rating, the next higher standard size of 800 amperes or less may be used if conditions are met

    Using the next higher standard size of 800 amperes or less when the ampacity does not match a standard rating is correct. Section 240.4(B) allows rounding up to the next standard overcurrent device where the device is 800 amperes or less, the conductors are not part of a multi-outlet receptacle branch circuit, and the ampacity does not correspond to a standard size. This allowance is not limited to continuous loads or motor circuits, and the device is not always required to be smaller than the conductor ampacity.

87. Section 210.8(A) requires ground-fault circuit-interrupter protection for 125-volt, 15- and 20-ampere receptacles in specified dwelling locations. Which of the following dwelling locations requires GFCI protection for receptacles?
    • A bedroom wall receptacle
    • A hallway receptacle more than 6 feet from any sink
    • A receptacle in a finished living-room entertainment center
    • A receptacle serving the kitchen countertop

    Correct answer: A receptacle serving the kitchen countertop

    A receptacle serving the kitchen countertop is correct. Section 210.8(A) lists kitchens, specifically receptacles serving countertop surfaces, among the dwelling locations requiring GFCI protection because of the proximity of water and grounded surfaces. General bedroom, hallway, and living-room receptacles are not among the GFCI-required dwelling locations under that subsection.

88. A homeowner installs a 125-volt, 20-ampere receptacle in an unfinished basement to serve a workbench. What protection does Section 210.8(A) require for this receptacle?
    • Arc-fault circuit-interrupter protection only
    • Ground-fault circuit-interrupter protection
    • Surge protection only
    • No special protection is required in a basement

    Correct answer: Ground-fault circuit-interrupter protection

    Ground-fault circuit-interrupter protection is correct. Section 210.8(A) requires GFCI protection for 125-volt, 15- and 20-ampere receptacles installed in unfinished portions of basements not intended as habitable rooms, where damp conditions and grounded surfaces raise shock risk. Arc-fault protection addresses arcing faults rather than ground faults, surge protection serves a different purpose, and the basement receptacle is not exempt.

89. The primary protective function of a ground-fault circuit interrupter, as required by Section 210.8, is best described as protecting against what hazard?
    • Overheating of conductors from overload
    • Arcing faults in damaged cords
    • Electric shock to people from a ground fault
    • Lightning-induced voltage surges

    Correct answer: Electric shock to people from a ground fault

    Protecting people against electric shock from a ground fault is correct. A GFCI device senses small imbalances between the ungrounded and grounded conductors, indicating current leaking to ground through a person or object, and opens the circuit at about 4 to 6 milliamperes to prevent a lethal shock. Overload heating is handled by overcurrent devices, arcing faults by AFCI devices, and surges by surge protectors.

90. Section 210.12 requires arc-fault circuit-interrupter protection for 120-volt, 15- and 20-ampere branch circuits supplying outlets in many dwelling areas. Which of the following dwelling areas is specifically included in the AFCI requirement?
    • Exterior receptacles on the porch
    • Bedrooms
    • Garages
    • Bathrooms

    Correct answer: Bedrooms

    Bedrooms is correct. Section 210.12(A) requires AFCI protection for 120-volt, 15- and 20-ampere branch circuits supplying outlets in dwelling-unit kitchens, family rooms, dining rooms, living rooms, bedrooms, and several other listed living areas. Bathrooms, garages, and outdoor receptacles are generally GFCI areas rather than part of the AFCI-listed living spaces.

91. What hazard is an arc-fault circuit interrupter specifically designed to detect and interrupt, as the basis for the Section 210.12 requirement?
    • A direct line-to-ground leakage current to a person
    • A sustained overload on the conductor
    • A drop in system voltage below nominal
    • A dangerous arcing condition in branch-circuit wiring

    Correct answer: A dangerous arcing condition in branch-circuit wiring

    A dangerous arcing condition in branch-circuit wiring is correct. An AFCI device recognizes the characteristic current signatures of unintended series or parallel arcing, such as from damaged or loose conductors, and opens the circuit to reduce the risk of fire. Leakage current to a person is the province of a GFCI, overloads are handled by the overcurrent device, and undervoltage is not the AFCI's function.

92. An electrician extends an existing 120-volt, 15-ampere branch circuit in a dwelling bedroom by adding a receptacle outlet. Under Section 210.12(D), what does the NEC require regarding arc-fault protection for this modified circuit?
    • No action is required because the original circuit predates the rule
    • The entire dwelling must be rewired with AFCI protection
    • AFCI protection must be provided where the branch circuit is extended or modified
    • Only GFCI protection is required for the added outlet

    Correct answer: AFCI protection must be provided where the branch circuit is extended or modified

    Providing AFCI protection where the branch circuit is extended or modified is correct. Section 210.12(D) requires that when a branch circuit in an AFCI-required area is modified, replaced, or extended, the added or extended portion be protected by a listed AFCI device such as an outlet branch-circuit AFCI or a combination AFCI breaker. The work is not exempt simply because the circuit is older, whole-house rewiring is not mandated, and GFCI protection does not satisfy the AFCI requirement.

93. Section 210.52(A) governs the general spacing of receptacle outlets along dwelling walls. What is the maximum distance permitted along a wall line so that no point measured horizontally along the floor line is more than a set distance from a receptacle?
    • No point more than 12 feet from a receptacle
    • Receptacles spaced not more than 8 feet apart
    • No point more than 6 feet from a receptacle, so receptacles are spaced not more than 12 feet apart
    • Receptacles spaced not more than 20 feet apart

    Correct answer: No point more than 6 feet from a receptacle, so receptacles are spaced not more than 12 feet apart

    Spacing so that no point along the wall line is more than 6 feet from a receptacle, giving a maximum of 12 feet between receptacles, is correct. Section 210.52(A) is built around the 6-foot rule so that an appliance cord of typical length can reach a receptacle without an extension cord. A flat 8-foot or 20-foot spacing, or a 12-foot maximum distance to a single receptacle, does not state the rule correctly.

94. Under Section 210.52(A), any wall space in a dwelling that is how wide or wider must be provided with a receptacle outlet?
    • 3 feet or wider
    • 2 feet or wider
    • 4 feet or wider
    • 18 inches or wider

    Correct answer: 2 feet or wider

    2 feet or wider is correct. Section 210.52(A)(2) defines a wall space that requires a receptacle as any space 2 feet or more in width, including space measured around corners but not interrupted by doorways or fireplaces. The 3-foot, 4-foot, and 18-inch values do not match the code's 2-foot threshold for counting wall space.

95. For receptacle outlets serving the countertops of a dwelling kitchen, Section 210.52(C) requires spacing so that no point along the counter wall line is more than what distance from a receptacle?
    • 12 inches
    • 36 inches
    • 48 inches
    • 24 inches

    Correct answer: 24 inches

    24 inches is correct. Section 210.52(C)(1) requires kitchen countertop receptacles to be placed so that no point along the wall line behind the counter is more than 24 inches from a receptacle, ensuring a 24-inch reach for countertop appliances. The other distances do not match the kitchen-counter spacing requirement.

96. A countertop in a dwelling kitchen has a wall section 30 inches wide behind it, measured between cabinet ends. Under Section 210.52(C), what does the NEC require for this counter space?
    • No receptacle is required because the space is under 4 feet
    • At least one receptacle outlet is required, because a counter space 12 inches or wider must be served
    • A receptacle is required only if a window is present
    • Two receptacles are required for any counter over 24 inches

    Correct answer: At least one receptacle outlet is required, because a counter space 12 inches or wider must be served

    Requiring at least one receptacle because the counter space is 12 inches or wider is correct. Section 210.52(C)(1) requires a receptacle for each kitchen counter wall space that is 12 inches or wider, and a 30-inch space clearly exceeds that threshold. The space is not exempt for being under 4 feet, a window does not control the requirement, and two receptacles are not mandated by width alone for a 30-inch space.

97. Section 240.21 generally requires overcurrent protection at the point where a conductor receives its supply. A tap conductor is best described as a conductor that does which of the following?
    • Is always larger than the conductor supplying it
    • Is protected by a device rated at exactly its ampacity
    • Is permitted only on services rated over 1,000 amperes
    • Has overcurrent protection ahead of it that exceeds the value allowed by its ampacity

    Correct answer: Has overcurrent protection ahead of it that exceeds the value allowed by its ampacity

    Having overcurrent protection ahead of it that exceeds the value normally permitted by its ampacity is correct. The tap rules of Section 240.21 allow a smaller conductor to be connected to a larger circuit without overcurrent protection at the tap point, provided length, termination, and physical-protection conditions are met. A tap is not defined by being larger than its supply, protected exactly at its ampacity, or limited to services over 1,000 amperes.

98. Under the 10-foot tap rule of Section 240.21(B)(1), a tap conductor not over 10 feet long must have an ampacity not less than what value relative to the device or conductors it supplies?
    • Not less than 10 percent of the feeder overcurrent device
    • Not less than the full feeder overcurrent device rating
    • Not less than the combined computed loads and at least the rating of the device supplied
    • Not less than 50 percent of the feeder ampacity

    Correct answer: Not less than the combined computed loads and at least the rating of the device supplied

    Having an ampacity not less than the combined computed loads and at least the rating of the device supplied is correct. The 10-foot tap rule in Section 240.21(B)(1) requires the tap conductor's ampacity to be sufficient for the load served and not less than the rating of the device or the overcurrent device at its termination, among other conditions. A flat 10 percent, the full feeder device rating, and a 50 percent feeder figure do not state the 10-foot tap ampacity requirement.

99. For a tap conductor installed under the 25-foot tap rule of Section 240.21(B)(2), the tap conductor must have an ampacity of at least what fraction of the rating of the overcurrent device protecting the feeder conductors?
    • One-tenth
    • One-half
    • Equal to the device
    • One-third

    Correct answer: One-third

    One-third is correct. The 25-foot tap rule in Section 240.21(B)(2) requires the tap conductor to have an ampacity not less than one-third of the rating of the overcurrent device protecting the feeder, and to terminate in a single device that limits the load to the tap conductor's ampacity. The one-tenth and one-half fractions, and a device-equal requirement, do not match the 25-foot tap rule.

100. A 400-ampere feeder is protected by a 400-ampere overcurrent device. An electrician installs a tap conductor under the 25-foot tap rule. What is the minimum ampacity the tap conductor must have?
     • 40 amperes
     • 200 amperes
     • 133 amperes
     • 400 amperes

     Correct answer: 133 amperes

     133 amperes is correct. Under the 25-foot tap rule of Section 240.21(B)(2), the tap conductor must have an ampacity of at least one-third of the feeder overcurrent device rating, so $\frac{400}{3} \approx 133\,\text{A}$. Using one-tenth gives 40 amperes, one-half gives 200 amperes, and the full 400-ampere figure ignores the one-third allowance the tap rule provides.

101. A 120-volt, 20-ampere branch circuit supplies receptacle outlets in a dwelling kitchen serving the countertop, and the homeowner is concerned about both shock and fire. Considering Sections 210.8 and 210.12, which combination of protection does the NEC require for this circuit?
     • GFCI protection only
     • Both GFCI protection and AFCI protection
     • AFCI protection only
     • Neither, because small-appliance circuits are exempt

     Correct answer: Both GFCI protection and AFCI protection

     Both GFCI protection and AFCI protection is correct. Kitchen countertop receptacles require GFCI protection under Section 210.8(A) for shock prevention, and the kitchen branch circuit also requires AFCI protection under Section 210.12(A) because the kitchen is among the listed living areas, so both protections apply. Providing only one, or claiming an exemption for the small-appliance circuit, does not satisfy both code requirements.

102. An installer protects a 12 AWG copper conductor, which has a small-conductor overcurrent limit of 20 amperes, with a 30-ampere breaker because the conductor's 90-degree ampacity is higher. Why does the NEC consider this installation a violation?
     • Because Section 240.4(D) caps overcurrent protection for 12 AWG copper at 20 amperes regardless of the higher ampacity
     • Because 12 AWG copper may never be used on a branch circuit
     • Because a 30-ampere breaker is not a standard size
     • Because the conductor must instead be protected at 15 amperes

     Correct answer: Because Section 240.4(D) caps overcurrent protection for 12 AWG copper at 20 amperes regardless of the higher ampacity

     Section 240.4(D) capping overcurrent protection for 12 AWG copper at 20 amperes regardless of the higher ampacity is correct. The small-conductor rule overrides the temperature-column ampacity, limiting 12 AWG copper to a 20-ampere device to protect against overheating at typical terminations. The 12 AWG conductor is widely used on branch circuits, 30 amperes is a standard size, and 12 AWG copper is protected at 20 amperes rather than 15 amperes.

103. An electrician replaces an old standard receptacle with a new one in a dwelling laundry area. Under Section 210.8(A), the receptacle replacement triggers what requirement at that location?
     • The branch circuit must be upgraded to 30 amperes
     • The replacement receptacle must be provided with GFCI protection where GFCI is now required for that location
     • A dedicated grounding rod must be driven at the outlet
     • The receptacle must be relocated at least 6 feet from the laundry sink

     Correct answer: The replacement receptacle must be provided with GFCI protection where GFCI is now required for that location

     Providing the replacement receptacle with GFCI protection where GFCI is now required for that location is correct. Section 210.8 requires that where a receptacle is replaced in a location that currently calls for GFCI protection, such as a laundry area near a sink, the replacement must be GFCI protected. Replacing a receptacle does not force a circuit upgrade to 30 amperes, a dedicated grounding rod, or relocation of the outlet.