Journeyman Electrician Licensing Exam — Questions and Answers

Question 1: If a circuit has apparent power of 5 kVA and true power of 4 kW, what is the power factor?

1.25
0.5
0.6
0.8 (Correct answer)

Correct answer: 0.8

Power factor = True power / Apparent power = 4 kW / 5 kVA = 0.8.

Question 2: What is the purpose of a motor starter?

To measure motor power consumption
To limit inrush current and provide overload protection when starting a motor (Correct answer)
To increase motor speed above nameplate rating
To convert AC power to DC for the motor

Correct answer: To limit inrush current and provide overload protection when starting a motor

A motor starter limits the high inrush current during startup and provides thermal overload protection during operation.

Question 3: Per NEC 250.52(A)(1), a metal underground water pipe used as a grounding electrode must have at least how many feet of direct earth contact?

10 feet (Correct answer)
8 feet
5 feet
15 feet

Correct answer: 10 feet

NEC 250.52(A)(1) requires a metal underground water pipe to be in direct contact with the earth for at least 10 feet to qualify as a grounding electrode.

Question 4: What is the voltage threshold above which NFPA 70E considers electrical work potentially hazardous?

12V DC
50V AC (Correct answer)
120V AC
240V AC

Correct answer: 50V AC

NFPA 70E establishes 50 volts AC as the threshold at which electrical shock becomes a significant hazard requiring safety precautions.

Question 5: What is the purpose of a GFCI device from a safety perspective?

To prevent fires caused by overloaded circuits
To measure total harmonic distortion
To protect people from electric shock by detecting ground faults as small as 5 milliamps (Correct answer)
To protect equipment from voltage surges

Correct answer: To protect people from electric shock by detecting ground faults as small as 5 milliamps

GFCIs detect ground fault currents as low as 4-6 milliamps and trip within milliseconds to prevent fatal electric shock.

Question 6: Which wiring method is specifically designed for use in wet or damp locations exposed to weather?

UF cable (Correct answer)
AC cable
NM cable
FMC

Correct answer: UF cable

Underground feeder (UF) cable is designed for direct burial and wet or damp locations, unlike standard NM cable.

Question 7: What is the nameplate 'service factor' of a motor?

The multiplier indicating how much above nameplate load the motor can handle continuously (Correct answer)
The efficiency rating of the motor
The insulation temperature class of the windings
The number of starts per hour permitted

Correct answer: The multiplier indicating how much above nameplate load the motor can handle continuously

The service factor is a multiplier that indicates how much above the rated load a motor can operate continuously without damage.

Question 8: Per NEC 250.56, if a single ground rod electrode has a resistance to earth exceeding what value, a supplemental electrode must be added?

100 ohms
50 ohms
15 ohms
25 ohms (Correct answer)

Correct answer: 25 ohms

NEC 250.56 requires a supplemental grounding electrode whenever a single rod electrode has a measured resistance exceeding 25 ohms.

Question 9: Two resistors of 6 ohms each are connected in parallel. What is the total resistance?

3 ohms (Correct answer)
6 ohms
12 ohms
1 ohm

Correct answer: 3 ohms

For two equal resistors in parallel, RT = R/2 = 6/2 = 3 ohms.

Question 10: What NEC article covers the installation of motors, motor circuits, and controllers?

Article 450
Article 430 (Correct answer)
Article 410
Article 440

Correct answer: Article 430

NEC Article 430 covers all aspects of motor circuits including conductors, overcurrent protection, controllers, and disconnecting means.

Question 11: What does PPE stand for in electrical safety?

Personal Protective Equipment (Correct answer)
Powered Protection Equipment
Personal Protection Equipment
Primary Protective Enclosure

Correct answer: Personal Protective Equipment

PPE stands for Personal Protective Equipment, which includes items like rubber gloves, face shields, and arc flash suits.

Question 12: What is the minimum size service entrance conductor required for a single-family dwelling per the NEC?

6 AWG copper
1/0 AWG copper
4 AWG copper (Correct answer)
2 AWG copper

Correct answer: 4 AWG copper

NEC 230.79 requires a minimum 100-ampere service for single-family dwellings, which corresponds to 4 AWG copper for service entrance conductors.

Question 13: How do you reverse the direction of a three-phase induction motor?

Change the motor control transformer tap
Interchange any two of the three phase conductors (Correct answer)
Reverse the grounding conductor
Swap any single hot leg with the neutral

Correct answer: Interchange any two of the three phase conductors

Reversing any two of the three-phase conductors reverses the rotating magnetic field direction, which reverses motor rotation.

Question 14: What does the NFPA 70E standard primarily address?

Utility transmission standards
Electrical safety in the workplace (Correct answer)
Installation requirements for wiring systems
Product listing requirements for electrical equipment

Correct answer: Electrical safety in the workplace

NFPA 70E: Standard for Electrical Safety in the Workplace covers safe work practices, PPE requirements, and hazard analysis.

Question 15: What is the minimum bending radius for 1-inch EMT?

8 inches
5 inches
6 inches (Correct answer)
4 inches

Correct answer: 6 inches

The NEC requires a minimum bending radius of 6 times the internal diameter for EMT to prevent conductor damage.

Question 16: What NEC article covers general requirements for wiring methods?

Article 100
Article 200
Article 300 (Correct answer)
Article 400

Correct answer: Article 300

NEC Article 300 covers general requirements for all wiring methods and materials.

Question 17: What is the maximum number of current-carrying conductors permitted in a single conduit before derating is required under the NEC?

4
3 (Correct answer)
6
2

Correct answer: 3

The NEC allows up to 3 current-carrying conductors before ampacity derating applies per NEC 310.15(C).

Question 18: Which wiring method is required in Class I, Division 1 hazardous locations?

PVC conduit
NM cable
MC cable
Rigid metal conduit (RMC) or equivalent (Correct answer)

Correct answer: Rigid metal conduit (RMC) or equivalent

Class I, Division 1 hazardous locations require rigid metal conduit or other approved methods to contain potential ignition sources.

Question 19: What does Kirchhoff's Current Law (KCL) state?

The sum of all currents entering a node equals the sum leaving it (Correct answer)
The sum of voltage drops equals the source voltage
Current is the same throughout a series circuit
Resistance increases with temperature

Correct answer: The sum of all currents entering a node equals the sum leaving it

KCL states that the algebraic sum of all currents entering and exiting a node must equal zero.

Question 20: In a parallel circuit, what happens to total resistance as more resistors are added?

It increases
It stays the same
It decreases (Correct answer)
It doubles

Correct answer: It decreases

Adding more resistors in parallel provides additional paths for current, reducing overall resistance.

Question 21: Per NEC 250.53(B), what is the minimum separation required between two ground rod electrodes when more than one is installed?

2 feet
8 feet
6 feet (Correct answer)
4 feet

Correct answer: 6 feet

NEC 250.53(B) requires ground rods to be spaced at least 6 feet apart so each rod contacts independent soil and resistance zones do not overlap.

Question 22: What is 'energized electrical work' as defined by NFPA 70E?

Testing a circuit with a voltmeter
Installation of new electrical equipment
Work performed on or near live parts that have not been placed in an electrically safe work condition (Correct answer)
Any work that requires running new wiring

Correct answer: Work performed on or near live parts that have not been placed in an electrically safe work condition

Energized electrical work is any task performed on or near conductors or circuit parts that have not been de-energized and verified safe.

Question 23: What is the minimum size copper grounding electrode conductor required for a service with 2/0 AWG copper service entrance conductors per NEC Table 250.66?

4 AWG (Correct answer)
6 AWG
1/0 AWG
2 AWG

Correct answer: 4 AWG

Per NEC Table 250.66, service entrance conductors in the 1/0–3/0 AWG range require a minimum 4 AWG copper grounding electrode conductor.

Question 24: How is armored cable (Type AC) different from metal-clad cable (Type MC)?

MC has an aluminum bonding strip; AC uses an internal bare wire that provides fault return (Correct answer)
They are identical
AC uses aluminum wire; MC uses copper
AC has an aluminum bonding strip; MC does not

Correct answer: MC has an aluminum bonding strip; AC uses an internal bare wire that provides fault return

Type MC cable contains an insulated equipment grounding conductor, while Type AC relies on an aluminum bonding strip inside the armor for fault current return.

Question 25: Per the NEC, what is the maximum length a flexible cord can be used as a substitute for fixed wiring?

25 feet
6 feet
Flexible cords are never permitted as fixed wiring (Correct answer)
10 feet

Correct answer: Flexible cords are never permitted as fixed wiring

The NEC prohibits using flexible cords as a substitute for fixed building wiring under NEC 400.12.

Question 26: What is the purpose of a neutral bar in a main electrical panel?

To distribute 240V circuits
To bond the panel to the building structure
To connect all hot conductors
To provide a common connection point for grounded (neutral) conductors (Correct answer)

Correct answer: To provide a common connection point for grounded (neutral) conductors

The neutral bar provides a terminal block where all grounded (neutral) conductors connect to complete the circuit back to the source.

Question 27: What is a 'separately derived system'?

A feeder that has its own dedicated panel
Any circuit over 50 amps
A system with no direct electrical connection to the supply side conductors of another system (Correct answer)
A circuit protected by a GFCI breaker

Correct answer: A system with no direct electrical connection to the supply side conductors of another system

A separately derived system, such as a transformer secondary, has no direct metallic connection to the supply conductors of another system.

Question 28: Before working on electrical equipment, what must a qualified electrician do first?

Put on rubber-soled shoes
Turn off all lights in the area
Notify the utility company
Verify the circuit is de-energized using a proper voltage tester (Correct answer)

Correct answer: Verify the circuit is de-energized using a proper voltage tester

NFPA 70E and OSHA require verification of de-energized state using an appropriate voltage-testing device before performing electrical work.

Question 29: What is the purpose of a control transformer in a motor control circuit?

To filter harmonic distortion from the motor
To step up voltage for the motor
To store energy during power interruptions
To provide a lower, safer voltage (typically 120V) for the control circuit (Correct answer)

Correct answer: To provide a lower, safer voltage (typically 120V) for the control circuit

A control transformer steps down the line voltage to a safer, lower voltage (usually 120V) for the control circuit components.

Question 30: What is the maximum number of disconnecting means permitted at a service entrance per the NEC?

8
6 (Correct answer)
4
2

Correct answer: 6

NEC 230.71 allows a maximum of six disconnects at a single service entrance location.

Question 31: According to the NEC, motor branch circuit conductors must be sized at what minimum percentage of the motor's full-load current (FLC)?

150%
100%
125% (Correct answer)
115%

Correct answer: 125%

NEC 430.22 requires motor branch circuit conductors to be sized at no less than 125% of the motor's full-load current.

Question 32: What does NEMA stand for in the context of motor control enclosures?

National Equipment Maintenance Administration
National Electrical Motor Association
National Electrical Manufacturers Association (Correct answer)
North American Electrical Motor Authority

Correct answer: National Electrical Manufacturers Association

NEMA stands for National Electrical Manufacturers Association, which sets standards for motor control enclosure ratings.

Question 33: Under OSHA, how frequently must extension cords used on construction sites be visually inspected?

Annually
Monthly
Before each use (Correct answer)
Weekly

Correct answer: Before each use

OSHA 1926.405 requires that flexible cords and cables be visually inspected before use on any shift for external defects.

Question 34: What is the primary purpose of equipment grounding in an electrical system?

To reduce electrical consumption
To increase circuit efficiency
To improve power factor
To provide a low-impedance fault current path back to the source (Correct answer)

Correct answer: To provide a low-impedance fault current path back to the source

Equipment grounding provides a low-impedance return path so overcurrent devices trip quickly during a ground fault, protecting people and equipment.

Question 35: What is the minimum approach distance for unqualified workers near exposed energized conductors at 120-240V?

Any distance with rubber gloves
3 feet
They must not approach — area must be guarded (Correct answer)
10 feet

Correct answer: They must not approach — area must be guarded

Unqualified workers must not work on or near exposed energized conductors; the area must be guarded or barricaded to prevent their approach.

Question 36: Per the NEC, where must the grounding electrode conductor connect to a ground rod?

Within the first 12 inches of the top (Correct answer)
Only at the midpoint
At the top of the rod only
Anywhere along the rod

Correct answer: Within the first 12 inches of the top

The grounding electrode conductor must be connected within the upper 12 inches (top) of the ground rod per NEC 250.70.

Question 37: What type of motor uses both a start winding and a run winding?

Synchronous motor
DC shunt motor
Three-phase induction motor
Single-phase split-phase motor (Correct answer)

Correct answer: Single-phase split-phase motor

A single-phase split-phase motor uses a start winding (with higher resistance) to create the phase shift needed for starting torque.

Question 38: What is the reactance of a capacitor called?

Inductive reactance
Capacitive reactance (Correct answer)
Conductance
Impedance

Correct answer: Capacitive reactance

The opposition a capacitor provides to AC current is called capacitive reactance (Xc), measured in ohms.

Question 39: Under the NEC, bonding of metal water piping systems is required when the piping is likely to become energized. What is this requirement found in?

Article 200
Article 300
Article 350
Article 250 (Correct answer)

Correct answer: Article 250

NEC Article 250 covers all grounding and bonding requirements, including bonding of metal piping systems.

Question 40: What is the frequency of standard AC power in the United States?

240 Hz
120 Hz
50 Hz
60 Hz (Correct answer)

Correct answer: 60 Hz

The US electrical grid operates at 60 Hz, meaning AC voltage completes 60 cycles per second.

Question 41: What is the purpose of a conduit body (LB, LL, LR)?

To ground the conduit system
To protect conductors from water
To splice conductors
To change direction and provide access to conductors (Correct answer)

Correct answer: To change direction and provide access to conductors

Conduit bodies are used to change the direction of a conduit run and provide access to conductors for pulling and maintenance.

Question 42: Which of the following best describes 'qualified person' under OSHA electrical standards?

Someone who has been trained to work on electrical systems and is aware of the hazards involved (Correct answer)
Any licensed electrician regardless of training
Anyone with a general contractor's license
Someone who has passed an OSHA safety course

Correct answer: Someone who has been trained to work on electrical systems and is aware of the hazards involved

OSHA defines a qualified person as one who has received specific training in and has demonstrated skills in the construction and operation of electrical equipment.

Question 43: What size fuse or breaker is typically used to protect a 200-amp service entrance?

150 amps
175 amps
200 amps (Correct answer)
250 amps

Correct answer: 200 amps

A 200-amp service is protected by a 200-amp main overcurrent device that matches the rated capacity of the service.

Question 44: The main bonding jumper in a service panel connects which two components?

The service entrance conductors to the branch circuit breakers
The neutral (grounded) bus to the equipment grounding bus and enclosure (Correct answer)
The ungrounded (hot) bus to the neutral bus
The grounding electrode directly to the service panel enclosure

Correct answer: The neutral (grounded) bus to the equipment grounding bus and enclosure

The main bonding jumper connects the neutral conductor to the equipment grounding conductor and service enclosure, establishing the required neutral-to-ground bond at the service.

Question 45: In which location is it NOT permissible to connect neutral conductors and equipment grounding conductors together?

At a remote subpanel fed from the same service (Correct answer)
At an outdoor transformer secondary used as a separately derived system
At the source of a separately derived system
At the service equipment panel

Correct answer: At a remote subpanel fed from the same service

Per NEC 250.142(B), neutral and equipment grounding conductors must not be interconnected at remote panelboards supplied from the same service.

Question 46: What is the formula for calculating the area of a circle (used for conduit fill calculations)?

A = πd
A = 2πr
A = πr
A = πr² (Correct answer)

Correct answer: A = πr²

The area of a circle is π times the radius squared (A = πr²), which is essential for conduit fill calculations.

Question 47: Per NEC 250.53(G), what is the minimum depth a ground rod electrode must be driven into the earth?

6 feet
8 feet (Correct answer)
4 feet
10 feet

Correct answer: 8 feet

NEC 250.53(G) requires ground rods to be driven to a depth of at least 8 feet to ensure adequate earth contact.

Question 48: What color is the outer jacket of 12 AWG NM cable (Romex)?

Yellow (Correct answer)
Orange
White
Gray

Correct answer: Yellow

12 AWG NM cable has a yellow outer jacket, while 14 AWG is white and 10 AWG is orange.

Question 49: Per the NEC, overload protection for a motor must trip at what maximum percentage of the motor's full-load current for motors with a 1.15 service factor?

125% (Correct answer)
115%
100%
140%

Correct answer: 125%

NEC 430.32 requires overload devices to trip at no more than 125% of the motor's nameplate full-load current for motors with a 1.15 service factor.

Question 50: A NEMA 4X enclosure provides protection against which of the following?

Dust only
High-voltage surges
Water splash and corrosion (Correct answer)
Explosive atmospheres

Correct answer: Water splash and corrosion

A NEMA 4X enclosure is designed to protect against water splash, dust, and corrosion, making it suitable for outdoor and food processing environments.

Question 51: What is the maximum rating of an inverse time circuit breaker used to protect a motor branch circuit per the NEC?

150% of motor FLC
125% of motor FLC
115% of motor FLC
250% of motor FLC (Correct answer)

Correct answer: 250% of motor FLC

NEC Table 430.52 allows inverse time (standard) circuit breakers to be sized up to 250% of the motor's full-load current for short-circuit protection.

Question 52: Per NEC Table 250.122, what is the minimum size copper equipment grounding conductor required for a circuit protected by a 20-ampere overcurrent device?

14 AWG
12 AWG (Correct answer)
10 AWG
16 AWG

Correct answer: 12 AWG

NEC Table 250.122 specifies that a 20-ampere overcurrent device requires a minimum 12 AWG copper equipment grounding conductor.

Question 53: A 240V, 5kW electric heater draws how many amps?

10.4 amps
5 amps
41.6 amps
20.8 amps (Correct answer)

Correct answer: 20.8 amps

Using I = P/V = 5000/240 ≈ 20.8 amps.

Question 54: According to the NEC, what minimum size copper conductor is required for a 20-ampere branch circuit?

8 AWG
14 AWG
10 AWG
12 AWG (Correct answer)

Correct answer: 12 AWG

The NEC requires a minimum of 12 AWG copper for a 20-ampere branch circuit per Table 310.16.

Question 55: What is the minimum conductor size required for a ground ring grounding electrode per NEC 250.52(A)(4)?

2 AWG bare copper (Correct answer)
4 AWG bare copper
1/0 AWG bare copper
6 AWG bare copper

Correct answer: 2 AWG bare copper

NEC 250.52(A)(4) requires a ground ring to consist of at least 2 AWG bare copper conductor encircling the building or structure.

Question 56: What is the purpose of a Variable Frequency Drive (VFD)?

To provide backup power during outages
To control motor speed by varying the frequency of the supply voltage (Correct answer)
To reduce motor starting current to zero
To convert single-phase power to three-phase

Correct answer: To control motor speed by varying the frequency of the supply voltage

A VFD controls AC motor speed by varying the frequency and voltage supplied to the motor.

Question 57: Per NEC Table 250.66, what is the maximum copper grounding electrode conductor size required regardless of how large the service entrance conductors are?

2/0 AWG copper
3/0 AWG copper (Correct answer)
4/0 AWG copper
250 kcmil copper

Correct answer: 3/0 AWG copper

NEC Table 250.66 caps the required grounding electrode conductor at 3/0 AWG copper, even for very large or paralleled service conductors.

Question 58: What is the first step in an arc flash hazard analysis?

Training all workers in arc flash awareness
Selecting appropriate PPE
Collecting electrical system data to determine incident energy levels (Correct answer)
Installing arc flash labels on all equipment

Correct answer: Collecting electrical system data to determine incident energy levels

The first step is collecting single-line diagrams, equipment ratings, and protective device data to calculate incident energy at each location.

Question 59: According to NEC 250.119, which of the following correctly identifies an equipment grounding conductor?

White or gray insulation
Green, green with yellow stripe, or bare (Correct answer)
Orange or blue insulation
Black or red insulation

Correct answer: Green, green with yellow stripe, or bare

NEC 250.119 requires equipment grounding conductors to be identified by green insulation, green with yellow stripe, or left bare.

Question 60: What is the primary purpose of using liquid-tight flexible metal conduit (LFMC)?

To increase current-carrying capacity
To allow movement and vibration while maintaining a watertight seal (Correct answer)
To reduce material costs
To reduce voltage drop

Correct answer: To allow movement and vibration while maintaining a watertight seal

LFMC is used where flexibility is needed and moisture protection is required, such as connections to HVAC equipment.

Question 61: What is the maximum support spacing for rigid metal conduit (RMC) per the NEC?

8 feet
10 feet (Correct answer)
5 feet
12 feet

Correct answer: 10 feet

The NEC requires RMC to be supported at least every 10 feet and within a certain distance of boxes and fittings.

Question 62: A circuit has a voltage of 120V and a resistance of 20 ohms. What is the current?

2 amps
4 amps
6 amps (Correct answer)
8 amps

Correct answer: 6 amps

Using Ohm's Law, I = V/R = 120/20 = 6 amps.

Question 63: What is the purpose of Lockout/Tagout (LOTO) procedures?

To lock electrical panels to prevent unauthorized access
To prevent accidental energization of equipment during maintenance (Correct answer)
To tag circuits that are overloaded
To secure tools at the end of the workday

Correct answer: To prevent accidental energization of equipment during maintenance

LOTO procedures ensure that hazardous energy sources are isolated and locked out before workers perform maintenance or servicing.

Question 64: What is EMT commonly called in the field?

Thin-wall conduit (Correct answer)
Rigid conduit
Flex conduit
Liquid-tight conduit

Correct answer: Thin-wall conduit

EMT (Electrical Metallic Tubing) is commonly called thin-wall conduit due to its lighter wall thickness compared to RMC.

Question 65: What unit is used to measure electrical resistance?

Ampere
Volt
Ohm (Correct answer)
Watt

Correct answer: Ohm

Electrical resistance is measured in ohms (Ω), named after physicist Georg Simon Ohm.

Question 66: What is the power factor of a purely resistive circuit?

1.0 (Correct answer)
0.5
0.8
0

Correct answer: 1.0

A purely resistive circuit has a power factor of 1.0 because voltage and current are perfectly in phase.

Question 67: What type of connector must be used when terminating EMT at an enclosure in a wet location?

Compression connector
Snap-in connector
Set-screw connector
Raintight compression connector (Correct answer)

Correct answer: Raintight compression connector

In wet locations, raintight compression connectors are required to maintain the integrity of the watertight seal at enclosure entries.

Question 68: Which of the following best describes inductance in an electrical circuit?

Dissipation of electrical energy
Opposition to change in voltage
Opposition to change in current (Correct answer)
Storage of electrical charge

Correct answer: Opposition to change in current

Inductance is the property of a conductor that opposes changes in current flow, measured in henries.

Question 69: What is 'locked rotor current' (LRC) in a motor?

The high inrush current drawn when the motor shaft cannot rotate at startup (Correct answer)
The current drawn when the motor runs at full speed
The current after the motor reaches operating temperature
The current when the motor runs with no load

Correct answer: The high inrush current drawn when the motor shaft cannot rotate at startup

Locked rotor current is the maximum current a motor draws at standstill (when the shaft is held or before it begins to turn).

Question 70: What is the minimum ampacity required for a service to a single-family dwelling per the NEC?

60 amps
100 amps (Correct answer)
200 amps
150 amps

Correct answer: 100 amps

NEC 230.79(C) requires a minimum 100-ampere service for single-family dwellings.

Question 71: What is the impedance of a circuit with 8 ohms resistance and 6 ohms reactance?

14 ohms
2 ohms
10 ohms (Correct answer)
7 ohms

Correct answer: 10 ohms

Impedance Z = √(R² + X²) = √(64 + 36) = √100 = 10 ohms.

Question 72: What is the purpose of a wire nut (twist-on wire connector)?

To ground conductors to the enclosure
To splice two or more conductors together (Correct answer)
To terminate conductors at a breaker
To reduce conductor ampacity

Correct answer: To splice two or more conductors together

Wire nuts (twist-on connectors) are used to join two or more conductors together in an approved manner inside a junction box.

Question 73: For a separately derived system such as a step-down transformer, where must the system bonding jumper be installed per NEC 250.30(A)(1)?

At the remote panelboard served by the transformer
At the source of the separately derived system (Correct answer)
At the first overcurrent device downstream of the transformer
At the transformer primary terminals

Correct answer: At the source of the separately derived system

NEC 250.30(A)(1) requires the system bonding jumper to be installed at the source of the separately derived system to establish the neutral-to-ground bond.

Question 74: What does a contactor do in a motor control circuit?

Measures motor power factor
Provides short circuit protection
Provides overload protection
Electrically switches the motor power circuit on and off (Correct answer)

Correct answer: Electrically switches the motor power circuit on and off

A contactor is an electrically operated switch (controlled by a low-voltage coil) used to switch the high-power motor circuit on and off.

Question 75: Which of the following is specifically prohibited from use as a grounding electrode per NEC 250.52(B)?

Metal underground gas piping (Correct answer)
Plate electrode buried 30 inches deep
Metal underground water pipe
Concrete-encased electrode (Ufer ground)

Correct answer: Metal underground gas piping

NEC 250.52(B)(1) explicitly prohibits metal underground gas piping from being used as a grounding electrode due to the explosion hazard from arcing.

Question 76: A transformer has a primary voltage of 480V and a turns ratio of 4:1. What is the secondary voltage?

120V (Correct answer)
240V
60V
1920V

Correct answer: 120V

Secondary voltage = Primary voltage / turns ratio = 480 / 4 = 120V.

Question 77: Per NEC 250.52(A)(3), a concrete-encased grounding electrode must contain at least how much bare copper conductor or rebar encased in the concrete?

10 feet
15 feet
25 feet
20 feet (Correct answer)

Correct answer: 20 feet

NEC 250.52(A)(3) requires at least 20 feet of bare copper conductor or rebar encased within a concrete foundation to qualify as a concrete-encased electrode.

Question 78: What is the function of a thermal overload relay in a motor control circuit?

To reverse motor direction
To protect the motor windings from excessive heat due to overload (Correct answer)
To start the motor remotely
To vary motor speed

Correct answer: To protect the motor windings from excessive heat due to overload

A thermal overload relay monitors motor current and trips to disconnect the motor if it draws excessive current that could overheat and damage the windings.

Question 79: What is the formula for calculating electrical power?

P = V / I
P = I / V
P = V + I
P = V × I (Correct answer)

Correct answer: P = V × I

Power (P) in watts equals voltage (V) multiplied by current (I), expressed as P = V × I.

Question 80: What is the RMS voltage of US standard household current if the peak voltage is approximately 170V?

85V
120V (Correct answer)
170V
155V

Correct answer: 120V

RMS voltage equals peak voltage multiplied by 0.707, so 170 × 0.707 ≈ 120V.

Question 81: What is the primary purpose of a grounding electrode system?

To provide the normal current return path from loads back to the source
To increase the impedance of the neutral conductor
To connect the electrical system to earth to stabilize voltage and dissipate lightning and transient surges (Correct answer)
To limit fault current magnitude in branch circuits

Correct answer: To connect the electrical system to earth to stabilize voltage and dissipate lightning and transient surges

The grounding electrode system connects the electrical system to earth to stabilize voltages to ground and safely dissipate lightning and transient overvoltages.

Question 82: What OSHA citation is typically issued when an employer's violation of a safety standard could cause death or serious physical harm?

Other-than-serious violation
Willful violation
Serious violation (Correct answer)
De minimis violation

Correct answer: Serious violation

OSHA issues a serious violation citation when there is substantial probability that death or serious physical harm could result from the hazardous condition.

Question 83: In a motor control circuit, what is a 'holding contact' used for?

To maintain a specific motor speed
To hold the motor shaft in place when stopped
To hold the overload relay in a tripped position
To maintain the starter coil energized after the start button is released (Correct answer)

Correct answer: To maintain the starter coil energized after the start button is released

A holding (or seal-in) contact is an auxiliary contact that keeps the motor starter coil energized after the momentary start button is released.

Question 84: Under the NEC, AFCI protection is now required in which residential room?

Bedroom (Correct answer)
Utility room
Bathroom
Garage

Correct answer: Bedroom

AFCI protection has been required in bedrooms since the 1999 NEC and has since expanded to most living areas.

Question 85: What is the primary advantage of a wye (star) motor winding configuration?

Reduced starting current and lower starting torque (Correct answer)
Higher starting torque than delta
Lower operating voltage requirement
Higher efficiency at full load than delta

Correct answer: Reduced starting current and lower starting torque

In wye-start configurations, voltage per winding is reduced to 58%, lowering starting current to approximately 33% of delta-start current.

Question 86: At what minimum depth below grade must a ground ring electrode be buried per NEC 250.52(A)(4)?

24 inches
36 inches
30 inches (Correct answer)
18 inches

Correct answer: 30 inches

NEC 250.52(A)(4) requires the ground ring conductor to be buried at least 30 inches (750 mm) below the earth's surface.

Question 87: What is the purpose of an Incident Energy Analysis?

To assess the efficiency of motors and transformers
To measure the power quality of electrical systems
To calculate a building's total electrical demand
To determine the amount of heat energy a worker could be exposed to during an arc flash event (Correct answer)

Correct answer: To determine the amount of heat energy a worker could be exposed to during an arc flash event

Incident Energy Analysis calculates the thermal energy (in cal/cm²) a worker could receive at a specific working distance during an arc flash.

Question 88: What is the total power consumed by a 120V circuit with 10 amps at a power factor of 0.8?

800 watts
960 watts (Correct answer)
1200 watts
1500 watts

Correct answer: 960 watts

True power P = V × I × PF = 120 × 10 × 0.8 = 960 watts.

Question 89: The NEC defines a 'feeder' as all circuit conductors between what two points?

Branch circuit device and outlet
Main panel and branch circuit overcurrent device (Correct answer)
Transformer and service entrance
Service entrance and main panel

Correct answer: Main panel and branch circuit overcurrent device

A feeder is defined as all circuit conductors between the service equipment or source of power and the final branch-circuit overcurrent device.

Question 90: What size knockout is required in an electrical box for 3/4-inch conduit?

1 inch
1/2 inch
3/4 inch (Correct answer)
1-1/4 inch

Correct answer: 3/4 inch

A 3/4-inch conduit requires a 3/4-inch knockout in the electrical box to maintain proper fitting.

Question 91: The conductor that runs from the grounding electrode system to the neutral conductor at the service equipment is called the:

Equipment grounding conductor (EGC)
System bonding jumper
Main bonding jumper
Grounding electrode conductor (GEC) (Correct answer)

Correct answer: Grounding electrode conductor (GEC)

The grounding electrode conductor (GEC) connects the grounding electrode system to the neutral bus at the service equipment, linking the electrical system to earth.

Question 92: In a series circuit, how does total resistance compare to individual resistors?

Total resistance equals the largest resistor
Total resistance is less than the smallest resistor
Total resistance is the sum of all resistors (Correct answer)
Total resistance is the average of all resistors

Correct answer: Total resistance is the sum of all resistors

In a series circuit, total resistance equals the sum of all individual resistances (RT = R1 + R2 + R3...).

Question 93: According to the NEC, what is the minimum burial depth for rigid metal conduit (RMC) under a residential driveway?

12 inches (Correct answer)
24 inches
6 inches
18 inches

Correct answer: 12 inches

The NEC requires RMC to be buried at least 6 inches under a residential driveway, but 12 inches is required under most other conditions.

Question 94: What NEC requirement applies to the motor disconnecting means?

It must be rated for 200% of motor FLC
It must be a circuit breaker
It must be in sight from the motor and controller (Correct answer)
It must be fused

Correct answer: It must be in sight from the motor and controller

NEC 430.102 requires the motor disconnecting means to be within sight from the motor location and within sight from the controller.

Question 95: What is the primary purpose of bonding metallic components together in an electrical system?

To increase the voltage level throughout the circuit
To establish electrical continuity so all metal parts remain at the same potential (Correct answer)
To increase resistance in the fault current path
To reduce the ampacity requirements of conductors

Correct answer: To establish electrical continuity so all metal parts remain at the same potential

Bonding connects metallic parts to maintain equal potential between them and provides a low-impedance path for fault current to operate overcurrent devices.

Question 96: What is the minimum insulation class rating for rubber gloves used on 480V systems?

Class 1 (7500V)
Class 2 (17000V)
Class 00 (500V)
Class 0 (1000V) (Correct answer)

Correct answer: Class 0 (1000V)

Class 0 rubber insulating gloves are rated for 1000V and are the minimum appropriate choice for work on 480V systems.

Question 97: What is an arc flash hazard?

A hazard from static electricity discharge
A hazard from touching a live wire with bare hands
A sudden release of energy caused by an electrical fault that produces extreme heat and blast pressure (Correct answer)
Overheating of a circuit due to sustained overload

Correct answer: A sudden release of energy caused by an electrical fault that produces extreme heat and blast pressure

An arc flash is a dangerous electrical explosion that releases intense heat (up to 35,000°F), light, pressure, and molten metal.

Question 98: What type of grounding electrode is considered the most effective?

Concrete-encased electrode (Ufer ground) (Correct answer)
Ground rod
Metal underground water pipe
Building steel

Correct answer: Concrete-encased electrode (Ufer ground)

The concrete-encased electrode (Ufer ground) is considered highly effective because the moisture in concrete provides excellent soil contact.

Question 99: What does 'service entrance' refer to?

The physical door to the electrical room
The conductors and equipment that bring power from the utility to the building's main disconnect (Correct answer)
The meter base installed by the utility
The grounding electrode system

Correct answer: The conductors and equipment that bring power from the utility to the building's main disconnect

The service entrance includes the service conductors, service equipment, and all components between the utility connection and the main disconnect.

Question 100: Which NEC article contains all of the requirements for grounding and bonding of electrical systems and equipment?

Article 250 (Correct answer)
Article 240
Article 300
Article 230

Correct answer: Article 250

NEC Article 250 is dedicated entirely to grounding and bonding requirements and is one of the most referenced articles on electrician licensing exams.

Journeyman Electrician Licensing Exam

The Journeyman Electrician exam tests knowledge of the National Electrical Code (NEC), electrical theory, wiring methods, grounding and bonding, motors, and safety regulations required to obtain a journeyman electrician license.

100

Questions

240 min

Time Limit

70%

To Pass

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