I85PREP
⌘ K
NE Journeyman Electrician study materials
NE Journeyman Electrician study resources

NE Journeyman Electrician practice questions

One question at a time. Build your NE Journeyman Electrician understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1General Electrical Knowledge and Theory

In a series circuit containing three resistors, which quantity is the same through every resistor?

  1. Resistance
  2. Voltage
  3. Power
  4. Current Correct answer.

Explanation

A series circuit provides only one path for electron flow, so the same current passes through every component in that single path. Voltage divides across the resistors in proportion to their resistance, and power differs because it depends on each resistor's voltage drop.

Question 2General Electrical Knowledge and Theory

A 120-volt circuit supplies a resistive load drawing 15 amperes. What is the resistance of the load?

  1. 135 ohms
  2. 1800 ohms
  3. 8 ohms Correct answer.
  4. 0.125 ohm

Explanation

Ohm's law states R = E / I, so 120 volts divided by 15 amperes equals 8 ohms. This is a direct application of the fundamental relationship among voltage, current, and resistance.

Question 3General Electrical Knowledge and Theory

What is the relationship between electrical power, voltage, and current in a direct-current circuit?

  1. Power equals voltage squared divided by current
  2. Power equals voltage divided by current
  3. Power equals current divided by voltage
  4. Power equals voltage multiplied by current Correct answer.

Explanation

The power formula for a DC circuit is P = E × I, so a load drawing 10 amperes at 120 volts consumes 1200 watts. The other arrangements invert or misapply the relationship and do not yield watts.

Question 4General Electrical Knowledge and Theory

A parallel circuit has two branches across a 120-volt source, with branch resistances of 60 ohms and 120 ohms. What is the total current supplied by the source?

  1. 1.33 amperes
  2. 1 ampere
  3. 2 amperes
  4. 3 amperes Correct answer.

Explanation

In a parallel circuit each branch sees the full source voltage, so the currents are 120/60 = 2 amperes and 120/120 = 1 ampere. Kirchhoff's current law gives a total of 3 amperes.

Question 5General Electrical Knowledge and Theory

What is the equivalent resistance of two 12-ohm resistors connected in parallel?

  1. 12 ohms
  2. 6 ohms Correct answer.
  3. 3 ohms
  4. 24 ohms

Explanation

For two equal resistors in parallel, the equivalent resistance is half the value of one resistor, so 12 divided by 2 equals 6 ohms. The general reciprocal formula 1/RT = 1/R1 + 1/R2 gives the same result.

Question 6General Electrical Knowledge and Theory

Which statement correctly describes the magnetic field produced by current flowing through a conductor?

  1. The field runs parallel to the conductor along its length
  2. The field forms concentric circles around the conductor, with direction given by the left-hand rule Correct answer.
  3. The field exists only at the ends of the conductor
  4. The field strength is independent of current magnitude

Explanation

Current through a conductor creates a magnetic field whose lines form concentric circles around the conductor. The left-hand rule (or right-hand rule, depending on convention) relates field direction to current direction, and field strength increases with current.

Question 7General Electrical Knowledge and Theory

According to Faraday's law, what happens when a conductor is moved through a magnetic field?

  1. The conductor loses its current-carrying capacity
  2. The magnetic field is permanently cancelled
  3. A voltage is induced in the conductor Correct answer.
  4. The conductor's resistance decreases

Explanation

Faraday's law states that a changing magnetic flux linking a conductor induces an electromotive force in it. This principle underlies generators and transformers, where relative motion or changing flux produces voltage.

Question 8General Electrical Knowledge and Theory

What is the phase relationship between voltage and current in a purely capacitive AC circuit?

  1. Voltage and current are in phase
  2. Current leads voltage by 90 degrees Correct answer.
  3. Voltage leads current by 90 degrees
  4. Current lags voltage by 45 degrees

Explanation

In a purely capacitive circuit, current reaches its peak before voltage does, so current leads voltage by 90 electrical degrees. This behavior is often remembered with the mnemonic CIVIL, where CIV indicates current leads in a capacitor.

Question 9General Electrical Knowledge and Theory

What is the phase relationship between voltage and current in a purely inductive AC circuit?

  1. Voltage leads current by 90 degrees Correct answer.
  2. Voltage and current are in phase
  3. Current leads voltage by 90 degrees
  4. Current leads voltage by 180 degrees

Explanation

In an inductor, the changing current produces a back EMF that opposes the change, causing voltage to peak before current does. Voltage therefore leads current by 90 electrical degrees in a purely inductive circuit.

Question 10General Electrical Knowledge and Theory

A transformer has 480 turns on its primary and 120 turns on its secondary. If the primary is energized at 480 volts, what is the secondary voltage?

  1. 120 volts Correct answer.
  2. 240 volts
  3. 1920 volts
  4. 60 volts

Explanation

The voltage ratio equals the turns ratio, so secondary voltage equals primary voltage times secondary turns divided by primary turns: 480 × (120/480) = 120 volts. This is a step-down transformer with a 4:1 ratio.

Question 11General Electrical Knowledge and Theory

A three-phase system has a line voltage of 480 volts and a balanced line current of 20 amperes at unity power factor. What is the approximate apparent power?

  1. 5.5 kVA
  2. 9.6 kVA
  3. 33.3 kVA
  4. 16.6 kVA Correct answer.

Explanation

Three-phase apparent power is calculated as the square root of three times line voltage times line current, so 1.732 × 480 × 20 equals approximately 16,600 volt-amperes, or 16.6 kVA. At unity power factor this apparent power equals real power.

Question 12General Electrical Knowledge and Theory

What is the primary purpose of a bonding jumper in an electrical installation?

  1. To ensure electrical continuity between metal parts that must be connected Correct answer.
  2. To increase the resistance of the grounding path
  3. To provide overload protection for the conductors
  4. To reduce the ampacity of the circuit

Explanation

A bonding jumper maintains electrical continuity between metal parts so they remain at the same potential, preventing dangerous voltage differences. This supports fault-current return and protects against electric shock.

Question 13General Electrical Knowledge and Theory

Which conductor property most directly determines its resistance for a given length and material?

  1. Insulation color
  2. Voltage rating of the insulation
  3. Cross-sectional area Correct answer.
  4. Ambient temperature only

Explanation

Resistance is inversely proportional to cross-sectional area, so a larger circular mil area reduces resistance. Length and material resistivity also matter, but among the choices only area directly changes resistance for fixed length.

Question 14General Electrical Knowledge and Theory

Why are alternating-current ammeters often operated through a current transformer rather than connected directly in the circuit?

  1. To eliminate the need for insulation on the conductors
  2. To measure large currents safely by stepping them down to a lower value Correct answer.
  3. To increase the current to a measurable level
  4. To convert alternating current into direct current

Explanation

A current transformer steps high primary current down to a standard lower secondary current, allowing safe metering with smaller instruments. It also isolates the measuring circuit from the high-voltage primary.

Question 15General Electrical Knowledge and Theory

A circuit contains a 30-ohm resistor and a 40-ohm inductive reactance in series. What is the impedance?

  1. 70 ohms
  2. 10 ohms
  3. 50 ohms Correct answer.
  4. 35 ohms

Explanation

Impedance in a series RL circuit is the vector sum of resistance and reactance, calculated as the square root of (30 squared plus 40 squared). That equals the square root of 2500, or 50 ohms.

Question 16General Electrical Knowledge and Theory

What is the effect of power factor correction capacitors on an inductive load's power factor?

  1. They convert real power into reactive power
  2. They increase the lagging reactive current and lower the power factor
  3. They have no effect on reactive current
  4. They reduce the lagging reactive current and bring the power factor closer to unity Correct answer.

Explanation

Capacitors supply leading reactive current that offsets the lagging reactive current drawn by inductive loads. This reduces total line current and improves power factor toward unity without changing the real power consumed.

Question 17General Electrical Knowledge and Theory

In a 120/240-volt single-phase, three-wire service, what is the voltage between the two ungrounded conductors?

  1. 360 volts
  2. 240 volts Correct answer.
  3. 120 volts
  4. 60 volts

Explanation

The two ungrounded conductors are supplied from opposite ends of the service transformer winding, so the voltage between them is the sum of the two 120-volt halves, or 240 volts. Each ungrounded conductor to neutral measures 120 volts.

Question 18General Electrical Knowledge and Theory

What does the term ampacity describe?

  1. The maximum voltage a conductor can withstand before insulation breakdown
  2. The total resistance of a conductor at operating temperature
  3. The amount of power a conductor dissipates at no load
  4. The maximum current a conductor can carry continuously under stated conditions without exceeding its temperature rating Correct answer.

Explanation

Ampacity is the current-carrying capacity of a conductor under specified conditions of use, limited by the temperature rating of the conductor and its insulation. It is not a voltage or resistance rating.

Question 19General Electrical Knowledge and Theory

A 240-volt, 5-kilowatt resistive heater operates at unity power factor. What current does it draw?

  1. 12 amperes
  2. 2.4 amperes
  3. 20.8 amperes Correct answer.
  4. 48 amperes

Explanation

Current is found by dividing power by voltage: 5000 watts divided by 240 volts equals approximately 20.8 amperes. At unity power factor, volt-amperes equal watts, so no additional correction is needed.

Question 20General Electrical Knowledge and Theory

Why does a short circuit produce a very large current compared with a normal load?

  1. The fault path has very low resistance, so Ohm's law yields a high current for the applied voltage Correct answer.
  2. The source frequency increases during a short circuit
  3. The voltage rises sharply during a short circuit
  4. The fault path has very high resistance, which increases current

Explanation

A short circuit creates a low-resistance path between points of different potential, and since current equals voltage divided by resistance, a small denominator produces a large current. This is why overcurrent protective devices must interrupt fault current quickly.

Question 21Wiring Methods and Materials

What is the minimum burial depth for Type UF cable directly buried under a residential lawn on a 120/240-volt branch circuit?

  1. 12 inches
  2. 6 inches
  3. 24 inches Correct answer.
  4. 18 inches

Explanation

Type UF cable used for direct burial on a 120/240-volt circuit must be at least 24 inches below grade. This depth applies to residential lawns and similar areas not subject to vehicular traffic.

Question 22Wiring Methods and Materials

Which wiring method is permitted to be installed in a concrete slab on grade?

  1. Liquidtight flexible nonmetallic conduit
  2. Rigid polyvinyl chloride conduit Correct answer.
  3. Surface metal raceway
  4. Electrical nonmetallic tubing

Explanation

Rigid PVC conduit is listed and permitted for direct burial in concrete, including slabs on grade. ENT is restricted from use in poured concrete, and surface raceways are not designed for embedding.

Question 23Wiring Methods and Materials

What is the maximum number of 90-degree bends permitted in a single run of rigid metal conduit between pull points?

  1. Four Correct answer.
  2. Two
  3. Six
  4. Three

Explanation

A single conduit run may contain no more than the equivalent of four quarter bends (360 degrees total) between pull points. This limit applies to all raceway types and prevents damage to conductors during pulling.

Question 24Wiring Methods and Materials

Type NM-B cable is permitted to be installed in which of the following locations?

  1. In the concealed space of a masonry block wall below grade Correct answer.
  2. Inside a dropped ceiling used as a return-air plenum
  3. Inside a raceway installed outdoors on a rooftop
  4. In a wet location subject to saturation

Explanation

NM cable is permitted in the concealed space of a masonry block wall, including below grade, as long as it is not in a wet location or in a plenum. NM cable is prohibited in ducts and plenums, in wet locations, and where exposed to weather.

Question 25Wiring Methods and Materials

A metal raceway is installed between two junction boxes, and the raceway is not otherwise used as an equipment grounding conductor. What must be done to ensure the metal raceway is electrically continuous?

  1. Install a grounding electrode conductor from the raceway to a ground rod
  2. Install an insulated equipment grounding conductor inside and ignore the raceway
  3. Rely on the locknuts alone to establish continuity
  4. Bond the raceway at both ends with listed bonding jumpers and fittings Correct answer.

Explanation

Metal raceways must be made electrically continuous and bonded to ensure a low-impedance fault path. Listed bonding jumpers and bonding fittings are required around components that might interrupt continuity, such as expansion joints.

Question 26Wiring Methods and Materials

What is the required support interval for 1-inch electrical metallic tubing installed horizontally in a dry location?

  1. Every 5 feet
  2. Every 12 feet
  3. Every 10 feet Correct answer.
  4. Every 3 feet

Explanation

EMT must be securely fastened at intervals not exceeding 10 feet and within 3 feet of every box or termination. The 10-foot interval is the general support rule for EMT.

Question 27Wiring Methods and Materials

A run of rigid metal conduit is installed outdoors and is subject to expansion and contraction. Which fitting is required at a joint to accommodate this movement?

  1. A bonding bushing
  2. A listed expansion fitting Correct answer.
  3. A standard coupling
  4. An Erickson coupling

Explanation

Where raceways are exposed to temperature changes that cause expansion or contraction, listed expansion fittings must be installed. The fitting allows the conduit to slide while maintaining electrical continuity.

Question 28Wiring Methods and Materials

Which of the following is an acceptable use for liquidtight flexible metal conduit?

  1. As a flexible connection to a motor subject to vibration in a damp location Correct answer.
  2. Buried directly in soil without a corrosion evaluation
  3. In a wet location without any additional protection
  4. Inside a hazardous location without seals

Explanation

Liquidtight flexible metal conduit is commonly used to connect motors and other vibrating equipment in damp or wet locations. Its flexible construction absorbs vibration while the outer jacket resists moisture.

Question 29Wiring Methods and Materials

What is the minimum size of a copper conductor permitted for use as a grounding electrode conductor to a driven ground rod?

  1. 4 AWG
  2. 8 AWG Correct answer.
  3. 6 AWG
  4. 14 AWG

Explanation

For a rod, pipe, or plate electrode, the grounding electrode conductor is not required to be larger than 6 AWG copper, and the minimum permitted size for this connection is 8 AWG copper. The size is based on the service conductor rating but capped at 6 AWG for this electrode type.

Question 30Wiring Methods and Materials

A 3-inch trade size rigid metal conduit is installed with a threaded coupling. Which of the following is required to ensure proper electrical continuity?

  1. A listed bonding bushing at the box end
  2. Threaded couplings made up tight with at least five threads engaged Correct answer.
  3. Bonding jumpers around the coupling
  4. A grounding electrode conductor connected to the coupling

Explanation

Threaded rigid metal conduit joints must be made up tight, with a minimum of five threads engaged, to ensure mechanical strength and electrical continuity. Properly made threaded joints provide the bonding path without additional jumpers.

Question 31Wiring Methods and Materials

Which of the following wiring methods is permitted in a Class I, Division 1 location as a general wiring method?

  1. Rigid metal conduit with threaded connections Correct answer.
  2. Surface metal raceway
  3. Type NM-B cable
  4. Electrical nonmetallic tubing

Explanation

In Class I, Division 1 locations, threaded rigid metal conduit is the standard permitted wiring method because it provides a robust, sealable raceway. Other methods require specific listing and are generally restricted.

Question 32Wiring Methods and Materials

What is the maximum spacing between supports for Type MC cable installed horizontally?

  1. 12 feet
  2. 10 feet
  3. 6 feet Correct answer.
  4. 3 feet

Explanation

Type MC cable must be supported at intervals not exceeding 6 feet and within 12 inches of every box or fitting. This spacing keeps the cable secure while allowing some flexibility.

Question 33Wiring Methods and Materials

Which of the following is required when Type AC cable is used to supply a luminaire in a suspended ceiling?

  1. An anti-short bushing at the armor termination Correct answer.
  2. An equipment grounding conductor run inside the cable
  3. A separate grounding electrode conductor
  4. A bonding jumper around each support

Explanation

Type AC cable requires an anti-short bushing at terminations to protect conductors from the cut edge of the armor. The armor of AC cable serves as the equipment grounding conductor, so a separate conductor is not required.

Question 34Wiring Methods and Materials

A junction box is installed in a ceiling and contains splices for a 20-ampere branch circuit. What is the minimum size of the box if it contains six 12 AWG conductors and no fittings?

  1. 18 cubic inches
  2. 20.25 cubic inches Correct answer.
  3. 15 cubic inches
  4. 12 cubic inches

Explanation

Each 12 AWG conductor requires 2.25 cubic inches of box volume. Six conductors require 13.5 cubic inches, but the box must also accommodate the required free space for splices and the largest box size meeting the minimum is 20.25 cubic inches when the splice and grounding allowances are included.

Question 35Wiring Methods and Materials

Which of the following is the minimum size of a pull box for a straight pull of 4 AWG conductors through a 2-inch raceway?

  1. 16 inches Correct answer.
  2. 12 inches
  3. 8 inches
  4. 24 inches

Explanation

For a straight pull, the pull box length must be at least eight times the trade diameter of the largest raceway. Eight times 2 inches equals 16 inches.

Question 36Wiring Methods and Materials

Which wiring method is permitted for a 15-ampere, 125-volt receptacle circuit in a dwelling unit bathroom?

  1. Type SE cable installed underground
  2. Type UF cable installed in a raceway in a damp location
  3. Type NM-B cable installed in a wet location
  4. Type NM-B cable installed through bored holes in studs Correct answer.

Explanation

NM-B cable is commonly used for bathroom receptacle circuits when run through framing members and protected where required. Bathroom receptacles are typically in dry or damp locations, not wet locations, and NM cable is suitable when installed properly.

Question 37Wiring Methods and Materials

What is the minimum cover requirement for rigid metal conduit installed under a driveway used by trucks?

  1. 18 inches
  2. 12 inches
  3. 6 inches
  4. 24 inches Correct answer.

Explanation

Where a raceway is buried under a street, driveway, or parking area subject to vehicular traffic, the minimum cover for rigid metal conduit is 24 inches. This protects the raceway from the loads imposed by vehicles.

Question 38Wiring Methods and Materials

A metal wireway is installed to carry conductors between two panelboards. Which of the following is required at each end of the wireway?

  1. A bonding jumper to the enclosure Correct answer.
  2. A grounding electrode conductor
  3. A listed expansion fitting
  4. A seal-off fitting

Explanation

Metal wireways must be bonded to the equipment they connect to ensure a continuous fault-current path. A bonding jumper or listed bonding fitting is required at the terminations.

Question 39Wiring Methods and Materials

Which of the following is the correct method for supporting Type SE cable installed vertically on a wall?

  1. Support within 12 inches of the top and every 30 inches thereafter
  2. Support every 10 feet with no box support
  3. Support only at the top and bottom
  4. Support within 12 inches of each box and every 6 feet Correct answer.

Explanation

Type SE cable must be supported within 12 inches of each box or fitting and at intervals not exceeding 6 feet. This prevents strain on terminations and keeps the cable secure.

Question 40Wiring Methods and Materials

A 1-inch trade size Schedule 40 PVC conduit is installed outdoors exposed to sunlight. What minimum support spacing applies?

  1. Every 10 feet
  2. Every 5 feet
  3. Every 12 feet
  4. Every 3 feet Correct answer.

Explanation

Schedule 40 PVC conduit must be supported at intervals not exceeding 3 feet and within 3 feet of each box or fitting. The closer spacing accounts for the lower rigidity of PVC.

Question 41Wiring Methods and Materials

Which of the following fittings is required where a conduit passes from an indoor dry location to an outdoor location in a hazardous area?

  1. An Erickson coupling
  2. An expansion fitting
  3. A bonding bushing
  4. A listed seal-off fitting Correct answer.

Explanation

Where a raceway crosses from a hazardous area to a nonhazardous area, a listed seal-off fitting is required to prevent gases from migrating through the conduit. The seal is installed as close as practicable to the boundary.

Question 42Wiring Methods and Materials

What is the maximum permitted distance from a box to the first support for Type NM cable?

  1. 24 inches
  2. 12 inches Correct answer.
  3. 6 inches
  4. 18 inches

Explanation

Type NM cable must be secured within 12 inches of every box or fitting and at intervals not exceeding 4.5 feet. The 12-inch rule keeps the cable from being strained at terminations.

Question 43Wiring Methods and Materials

A feeder is installed in a rigid PVC conduit that is exposed to direct sunlight on a rooftop. Which of the following is required for the PVC conduit?

  1. A grounding electrode conductor
  2. A listed expansion fitting Correct answer.
  3. A bonding jumper around each coupling
  4. A seal-off fitting

Explanation

PVC conduit expands and contracts significantly with temperature changes, so a listed expansion fitting is required where the conduit is exposed to large temperature swings such as on a rooftop. The fitting prevents damage to joints and terminations.

Question 44Wiring Methods and Materials

Which of the following is a permitted use of surface metal raceway?

  1. Embedded in a concrete slab
  2. Exposed on a wall in a dry location Correct answer.
  3. Buried directly in soil
  4. Concealed inside a wall cavity

Explanation

Surface metal raceway is designed for exposed mounting on surfaces such as walls and ceilings in dry locations. It is not intended for concealment, embedding, or direct burial.

Question 45Wiring Methods and Materials

A 20-ampere branch circuit uses Type MC cable with an insulated equipment grounding conductor. Which of the following statements about the armor of the MC cable is correct?

  1. The armor must be removed and replaced with a bare conductor
  2. The armor is not permitted to be bonded
  3. The armor may serve as an equipment grounding conductor only if listed and identified for that use Correct answer.
  4. The armor is the sole equipment grounding conductor

Explanation

The armor of Type MC cable is permitted to serve as an equipment grounding conductor only where the cable is listed and identified for that use. Otherwise, a separate insulated equipment grounding conductor must be provided.

Question 46Wiring Methods and Materials

When Type NM cable is run through a bored hole in a wood framing member and the hole is not firestopped or otherwise protected, what minimum distance must the cable edge be kept from the nearest edge of the framing member?

  1. 1 1/2 inches
  2. 2 inches
  3. 1 inch
  4. 1 1/4 inches Correct answer.

Explanation

Section 334.17 requires that where NM cable is run through bored holes in studs or joists, the cable must be kept at least 1 1/4 inches from the nearest edge of the wood member unless the hole is protected by a steel plate or the framing is not likely to be penetrated by nails or screws.

Question 47Wiring Methods and Materials

A rigid metal conduit run is installed in a concrete slab on grade in a corrosive soil area. Which of the following is required to protect the conduit from corrosion?

  1. The conduit must be wrapped with 10-mil tape at all couplings only.
  2. The conduit must be listed and identified for direct burial and be provided with corrosion protection approved for the soil conditions. Correct answer.
  3. The conduit must be painted with a bituminous coating after installation.
  4. No protection is required because the concrete encasement isolates the conduit from the soil.

Explanation

Section 344.10 requires that where ferrous raceways are subject to severe corrosive influences, they must be protected by a corrosion-resistant coating or be of a material suitable for the environment, and listed for the condition. Concrete alone is not an acceptable substitute where the soil is corrosive.

Question 48Wiring Methods and Materials

A 3/4-inch trade size electrical nonmetallic tubing is installed in a concealed ceiling space of a building. What is the maximum permitted support spacing for the tubing?

  1. 3 feet Correct answer.
  2. 10 feet
  3. 4 1/2 feet
  4. 6 feet

Explanation

Section 362.30 requires ENT to be securely fastened in place at intervals not exceeding 3 feet and within 3 feet of every box or fitting. The tighter spacing reflects the flexible nature of the tubing compared with rigid raceways.

Question 49Wiring Methods and Materials

A metal junction box is installed in a wall and contains splices of 12 AWG conductors. What minimum volume allowance must be provided for each 12 AWG conductor in the box?

  1. 1.75 cubic inches
  2. 2.25 cubic inches Correct answer.
  3. 3.00 cubic inches
  4. 2.00 cubic inches

Explanation

Table 314.16(B) assigns a volume allowance of 2.25 cubic inches for each 12 AWG conductor. The box volume must be at least the sum of the allowances for all conductors, equipment grounding conductors, and device or fitting allowances.

Question 50Wiring Methods and Materials

A feeder circuit of 200 amperes is installed in a metal wireway that is 4 inches wide and 4 inches deep. The wireway contains 30 current-carrying conductors. Which of the following describes the required ampacity adjustment?

  1. The ampacity must be adjusted to 40 percent of the conductor ampacity from the tables. Correct answer.
  2. The ampacity must be adjusted to 70 percent of the conductor ampacity from the tables.
  3. The ampacity must be adjusted to 50 percent of the conductor ampacity from the tables.
  4. No adjustment is required because the conductors are in a wireway rather than a raceway.

Explanation

Section 376.22 requires that where more than 30 current-carrying conductors are installed in a metal wireway, the allowable ampacity of each conductor must be reduced in accordance with the adjustment factors in Table 310.15(B)(3)(a). For 31 to 40 conductors the factor is 40 percent, and the 30-conductor threshold is exceeded here.