Journeyman Electrician (NEC) — All Questions

Along a dwelling kitchen countertop, no point measured horizontally along the wall line may be more than what distance from a receptacle outlet?

• a.36 inches
• b.24 inches✓
• c.48 inches
• d.12 inches

No point along the kitchen counter wall line may be more than 24 inches from a receptacle, which places outlets no more than 48 inches apart. See NEC 210.52(C)(1).

A kitchen countertop or work surface must have a receptacle outlet if it is at least what width?

• a.12 inches✓
• b.18 inches
• c.6 inches
• d.24 inches

A countertop or work surface that is 12 inches or wider must be provided with at least one receptacle outlet. See NEC 210.52(C)(1).

At least one receptacle outlet must be installed within what distance of the outside edge of each dwelling bathroom basin?

• a.6 feet
• b.3 feet✓
• c.2 feet
• d.1 foot

A receptacle must be located within 3 feet of the outside edge of each basin, on a wall or partition adjacent to the basin or on the basin countertop. See NEC 210.52(D).

What is the minimum branch-circuit rating required for the dwelling laundry receptacle outlet(s)?

• a.15 amperes
• b.30 amperes
• c.20 amperes✓
• d.25 amperes

At least one 20-ampere branch circuit must supply the laundry receptacle outlet(s), and it may not serve other outlets. See NEC 210.11(C)(2) and 210.52(F).

Using the standard method, what is the general lighting load for a 2,500-square-foot dwelling before demand factors?

• a.5,625 volt-amperes
• b.11,250 volt-amperes
• c.7,500 volt-amperes✓
• d.6,000 volt-amperes

Dwelling general lighting is 3 volt-amperes per square foot: 2,500 x 3 = 7,500 VA. See NEC Table 220.12; verify the VA-per-square-foot value for the NEC edition your jurisdiction has adopted.

An apartment has the two required small-appliance branch circuits and no laundry circuit. What load must be included for the small-appliance circuits before demand factors?

• a.3,000 volt-amperes✓
• b.6,000 volt-amperes
• c.4,500 volt-amperes
• d.1,500 volt-amperes

Each small-appliance branch circuit is calculated at 1,500 VA: 2 x 1,500 = 3,000 VA. See NEC 220.52(A).

Using Column C of the household cooking-appliance demand table, what is the demand load for two 12-kilowatt household ranges on one feeder?

• a.11 kilowatts✓
• b.10 kilowatts
• c.8 kilowatts
• d.16 kilowatts

Column C of Table 220.55 gives 11 kilowatts for two household ranges rated not over 12 kilowatts each. See NEC 220.55.

Using the standard demand table, what is the demand load for a single 16-kilowatt household electric range?

• a.8 kilowatts
• b.16 kilowatts
• c.9.6 kilowatts✓
• d.12 kilowatts

Column C for one range is 8 kilowatts. Note 1 increases that value 5 percent for each kilowatt over 12: 16 kW is 4 over, so 8 x 1.20 = 9.6 kilowatts. See NEC Table 220.55, Note 1.

A dwelling has a single household electric clothes dryer with a nameplate rating of 5.5 kilowatts. What value must be used for the dryer load?

• a.4,000 volt-amperes
• b.5,000 volt-amperes
• c.5,250 volt-amperes
• d.5,500 volt-amperes✓

The dryer load is 5,000 VA or the nameplate rating, whichever is larger: 5,500 exceeds 5,000, so 5,500 VA is used. See NEC 220.54.

A dwelling feeder supplies three fastened-in-place appliances other than ranges, dryers and heating or air-conditioning equipment. What demand factor may be applied to their nameplate total?

• a.65 percent
• b.75 percent
• c.100 percent✓
• d.50 percent

The 75 percent demand factor requires four or more such fastened-in-place appliances; with only three, no reduction is permitted. See NEC 220.53.

Using the optional dwelling calculation, the general loads total 30 kVA. What is the demand load for these general loads?

• a.30 kVA
• b.22 kVA
• c.12 kVA
• d.18 kVA✓

The optional method takes the first 10 kVA at 100 percent and the remainder at 40 percent: 10 + (20 x 0.40) = 18 kVA. See NEC 220.82(B).

A commercial building has 40 general-use receptacle outlets. Using the standard method, what receptacle load must be calculated before demand factors?

• a.6,000 volt-amperes
• b.4,800 volt-amperes
• c.7,200 volt-amperes✓
• d.7,920 volt-amperes

Non-dwelling receptacle outlets are calculated at 180 VA each: 40 x 180 = 7,200 VA. See NEC 220.14(I).

A retail store has 15 linear feet of show window. What show-window load must be included?

• a.1,800 volt-amperes
• b.1,500 volt-amperes
• c.2,700 volt-amperes
• d.3,000 volt-amperes✓

Show-window lighting is calculated at 200 VA per linear foot of show window: 15 x 200 = 3,000 VA. See NEC 220.14(G).

A store lighting load of 20 amperes operates continuously. What is the minimum standard branch-circuit overcurrent device rating?

• a.20 amperes
• b.30 amperes
• c.35 amperes
• d.25 amperes✓

The device must be at least 125 percent of the continuous load: 20 x 1.25 = 25 A, which is a standard rating. See NEC 210.20(A).

A feeder supplies 50 amperes of continuous load plus 40 amperes of noncontinuous load. Using 75 degrees C copper terminations, what is the minimum conductor size?

• a.1 AWG
• b.2 AWG✓
• c.3 AWG
• d.4 AWG

Required ampacity = noncontinuous + 125 percent continuous = 40 + (50 x 1.25) = 102.5 A. In the 75 degrees C column 3 AWG (100 A) fails and 2 AWG (115 A) qualifies. See NEC 215.2(A)(1) and Table 310.16.

Four current-carrying 10 AWG THHN copper conductors share one raceway at a 30 degrees C ambient. What is the adjusted ampacity of each before termination limits?

• a.28 amperes
• b.30 amperes
• c.32 amperes✓
• d.35 amperes

The 90 degrees C ampacity of 10 AWG copper is 40 A, and the 4 to 6 conductor adjustment is 80 percent: 40 x 0.80 = 32 A. The final overcurrent device is still limited to 30 A by NEC 240.4(D). See NEC 310.15(C)(1).

A feeder neutral has a maximum unbalanced load of 250 amperes of non-nonlinear line-to-neutral load. Applying the permitted demand factor, what is the calculated neutral load?

• a.175 amperes
• b.250 amperes
• c.225 amperes
• d.235 amperes✓

For a feeder or service, the first 200 A of unbalanced neutral load is taken at 100 percent and the portion over 200 A at 70 percent: 200 + (50 x 0.70) = 235 A. See NEC 220.61(B).

A branch circuit supplies a 44-ampere continuous load. What is the minimum standard overcurrent device rating?

• a.50 amperes
• b.55 amperes
• c.70 amperes
• d.60 amperes✓

44 x 1.25 = 55 A, which is not a standard rating, so the next standard size of 60 A must be used. See NEC 210.20(A) and 240.6(A).

A 120-volt branch circuit shows a measured voltage drop of 4.8 volts. What is the percentage voltage drop?

• a.4 percent✓
• b.5 percent
• c.3 percent
• d.2 percent

Percentage voltage drop = 4.8 / 120 = 0.04, or 4 percent, which exceeds the 3 percent branch-circuit guideline. See the Informational Note to NEC 210.19.

A single receptacle is installed on an individual 20-ampere branch circuit. What is the minimum ampere rating of that receptacle?

• a.20 amperes✓
• b.30 amperes
• c.25 amperes
• d.15 amperes

A single receptacle on an individual branch circuit must have an ampere rating not less than the branch-circuit rating: 20 A. See NEC 210.21(B)(1).

What is the maximum continuous load permitted on a 15-ampere branch circuit?

• a.18 amperes
• b.12 amperes✓
• c.15 amperes
• d.10 amperes

A continuous load may not exceed 80 percent of the overcurrent device rating: 15 x 0.80 = 12 A. See NEC 210.20(A).

A dwelling has a combined general lighting, small-appliance and laundry load of 8,000 volt-amperes. Applying the standard demand factors, what is the demand load?

• a.4,750 volt-amperes✓
• b.8,000 volt-amperes
• c.2,800 volt-amperes
• d.5,000 volt-amperes

The dwelling lighting demand table takes the first 3,000 VA at 100 percent and the remainder at 35 percent: 3,000 + (5,000 x 0.35) = 4,750 VA. See NEC Table 220.45 (renumbered from Table 220.42 in the 2023 NEC).

In a dwelling-unit load calculation, how are the general-use 15- and 20-ampere receptacle outlets handled?

• a.They are calculated at 180 volt-amperes each in addition to the lighting load
• b.They are omitted from the load calculation entirely
• c.They are calculated at 1.5 amperes each
• d.They are included in the general lighting volt-amperes and are not calculated separately✓

In dwelling units, general-use receptacle outlets and lighting outlets are considered part of the general lighting load at 3 VA per square foot and no additional volt-amperes are added for them. See NEC 220.14(J).

A branch circuit supplies a 32-ampere continuous load. Using 75 degrees C copper terminations, what is the minimum conductor size?

• a.6 AWG
• b.10 AWG
• c.12 AWG
• d.8 AWG✓

The conductor must carry at least 125 percent of the continuous load: 32 x 1.25 = 40 A. In the 75 degrees C column 10 AWG (35 A) fails and 8 AWG (50 A) qualifies. See NEC 210.19(A) and Table 310.16.

Which dwelling-unit location requires arc-fault circuit-interrupter protection for 120-volt, 15- and 20-ampere branch circuits?

• a.A bathroom
• b.A bedroom✓
• c.An unfinished basement
• d.An outdoor receptacle

AFCI protection covers most habitable dwelling areas, including bedrooms, kitchens, living rooms and laundry areas. Bathrooms, unfinished basements and outdoor receptacles are addressed by GFCI rather than AFCI requirements. See NEC 210.12(A).

Which dwelling-unit location requires GFCI protection for 125-volt, 15- and 20-ampere receptacles?

• a.A living-room wall receptacle
• b.A bedroom receptacle
• c.A hallway receptacle
• d.A garage✓

NEC 210.8(A) lists garages among the GFCI areas along with bathrooms, kitchens, laundry areas, basements, crawl spaces and outdoors. Living rooms, bedrooms and hallways are AFCI areas instead.

A feeder supplies a 60-ampere continuous load. What is the minimum standard overcurrent device rating?

• a.70 amperes
• b.75 amperes
• c.80 amperes✓
• d.90 amperes

60 x 1.25 = 75 A, which is not a standard rating, so the next standard size of 80 A must be used. See NEC 215.3 and 240.6(A).

An electric-vehicle supply equipment branch circuit serves a 40-ampere EV charging load. What minimum overcurrent device and conductor ampacity are required?

• a.50 amperes✓
• b.45 amperes
• c.60 amperes
• d.40 amperes

Electric-vehicle charging load is treated as continuous, so the overcurrent device and conductors are sized at 125 percent: 40 x 1.25 = 50 A. See NEC 625.41 and 625.42.

A dwelling has a combined general lighting, small-appliance and laundry load of 3,600 volt-amperes. Applying the standard demand factors, what is the demand load?

• a.3,600 volt-amperes
• b.3,150 volt-amperes
• c.3,210 volt-amperes✓
• d.1,260 volt-amperes

The first 3,000 VA is taken at 100 percent and the remainder at 35 percent: 3,000 + (600 x 0.35) = 3,210 VA. See NEC Table 220.45.