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JOURNEYMAN ELECTRICIAN EXAM PRACTICE QUESTIONS (1–
100) WHITH CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+
1. What is the maximum allowable voltage drop for a branch circuit in a dwelling? A. 1% B. 3% C. 5% D. 10% Answer: B Branch circuits should have a voltage drop of no more than 3% to maintain efficiency, 2. Which conductor color is typically used for a grounded (neutral) conductor? A. Black B. White C. Green D. Red Answer: B White is standard for neutral conductors under the NEC. 3. What is the primary purpose of a GFCI? A. Protect against overcurrent B. Protect against ground faults C. Prevent voltage drop D. Increase amperage capacity Answer: B GFCIs trip when a ground fault occurs, preventing shock hazards. 4. In a 120/240V single-phase system, what is the voltage between the two hot legs? A. 120V B. 208V C. 240V D. 480V Answer: C The two hot legs in a single-phase system provide 240V.
5. Which type of conduit is flexible and often used for vibration-prone areas? A. EMT B. RMC C. FMC D. IMC Answer: C Flexible Metal Conduit (FMC) is designed for areas where vibration occurs. 6. What is the minimum size copper grounding electrode conductor for a 100A service? A. #8 AWG B. #6 AWG C. #4 AWG D. #2 AWG Answer: B NEC Table 250.66 specifies #6 copper for a 100A service. 7. Which device interrupts power when current exceeds a set value? A. Fuse B. Transformer C. Conductor D. Switch Answer: A A fuse melts when current exceeds its rating, protecting the circuit. 8. How many total wires are required in a typical 120/240V single-phase branch circuit with a neutral and ground? A. 2 B. 3 C. 4 D. 5 Answer: C Two hots, one neutral, and one ground make four conductors. 9. Which type of wire insulation is suitable for wet locations? A. NM-B B. UF-B C. THHN D. MTW Answer: B Underground Feeder (UF-B) is rated for wet locations.
Answer: B Fuses respond quickly to overcurrent, primarily short circuits.
15. What is the NEC limit for spacing between receptacles in a dwelling living room? A. 6 ft B. 10 ft C. 12 ft D. 15 ft Answer: D NEC requires receptacles so that no point along a wall is more than 6 feet from an outlet, which equates to spacing roughly every 12 feet. 16. Which conductor is used for equipment grounding? A. Black B. White C. Green D. Red Answer: C Green or bare copper conductors are for grounding. 17. What is the main purpose of a junction box? A. Increase voltage B. Protect connections C. Support equipment D. Ground circuits Answer: B Junction boxes protect splices and connections from damage and fire hazards. 18. How many watts can a 20A, 120V branch circuit safely supply continuously? A. 1200 W B. 1440 W C. 1920 W D. 2400 W Answer: C 20A x 120V = 2400W; for continuous load, use 80% rule → 2400 x 0.8 = 1920W. 19. What is the purpose of conduit fill calculations? A. Determine conduit length B. Ensure conductors fit safely C. Calculate voltage drop
D. Size breakers Answer: B Conduit fill ensures wires can be installed without damage or overheating.
20. Which NEC article covers wiring methods and materials? A. Article 100 B. Article 200 C. Article 300 D. Article 400 Answer: C Article 300 addresses wiring methods, materials, and installation requirements. 21. What is the maximum overcurrent protection for #14 AWG copper conductors? A. 10A B. 15A C. 20A D. 25A Answer: B NEC Table 310.15(B)(16) specifies 15A maximum for #14 copper. 22. Which type of breaker is required to protect a bedroom circuit? A. GFCI B. AFCI C. Standard breaker D. Dual-function breaker Answer: B Arc-Fault Circuit Interrupters are required for bedrooms to prevent fire hazards. 23. What is the standard residential service voltage in the U.S.? A. 120V only B. 240V only C. 120/240V single-phase D. 208Y/120V Answer: C Most homes use 120/240V single-phase service. 24. Which tool is used to check continuity of a conductor? A. Voltmeter B. Ohmmeter
C. Black D. Bare Answer: C Black is standard for ungrounded (hot) conductors.
30. What is the primary purpose of a bonding jumper? A. Conduct normal current B. Connect metal parts to ground C. Insulate conductors D. Reduce voltage drop Answer: B Bonding ensures all metal parts are at the same potential to prevent shock. 31. Which NEC article covers GFCI protection? A. Article 210 B. Article 220 C. Article 240 D. Article 250 Answer: A Article 210 outlines branch-circuit requirements including GFCI protection. 32. What is the maximum number of conductors allowed in a 3/4” EMT conduit? A. 6 #12 conductors B. 8 #12 conductors C. 9 #12 conductors D. 10 #12 conductors Answer: C NEC Chapter 9, Table 1, and Annex C provide conduit fill limits. 33. Which type of wire is rated for high temperature and dry locations? A. NM-B B. THHN C. UF-B D. SEU Answer: B THHN is rated for dry locations and higher temperatures (up to 90°C). 34. What is the maximum load per square foot for a general lighting branch circuit? A. 2 W/ft²
B. 3 W/ft² C. 5 W/ft² D. 10 W/ft² Answer: C NEC standard load for general lighting is 3 VA per square foot in dwelling units.
35. Which grounding electrode is required if a metal water pipe is present? A. Rod only B. Pipe only C. Rod and pipe D. None Answer: C Both metal water pipes and a rod may be required for grounding per NEC 250.52. 36. What is the minimum height of overhead service conductors over a residential driveway? A. 10 ft B. 12 ft C. 14 ft D. 18 ft Answer: C NEC requires 12–14 ft clearance over residential driveways; exact depends on local code. 37. Which conductor type is most common for branch circuits in homes? A. Aluminum THHN B. Copper NM-B C. Aluminum SE D. Copper MC Answer: B NM-B (Romex) copper is standard for residential branch circuits. 38. Which device provides short-circuit and overload protection for appliances? A. Receptacle B. Switch C. Circuit breaker D. Junction box Answer: C Circuit breakers protect circuits from overcurrent and short-circuits. 39. What is the maximum distance between support straps for NM cable? A. 2 ft
B. PVC
C. RMC
D. FMC
Answer: B PVC conduit is non-metallic, corrosion-resistant, and suitable for underground installation.
45. What is the maximum continuous load on a 15A, 120V branch circuit? A. 1440 W B. 1500 W C. 1600 W D. 1800 W Answer: A 15A x 120V = 1800W; continuous load limit is 80% → 1440W. 46. Which type of wire is suitable for direct burial without conduit? A. NM-B B. UF-B C. THHN D. MC Answer: B UF-B is rated for direct burial and wet locations. 47. What is the minimum size grounding electrode conductor for a 200A service using copper? A. #6 AWG B. #4 AWG C. #2 AWG D. #1/0 AWG Answer: B NEC Table 250.66 specifies #4 AWG copper for 200A service. 48. What is the main function of a transformer? A. Protect circuits from overload B. Convert voltage levels C. Measure current D. Provide grounding Answer: B Transformers increase or decrease voltage for distribution. 49. What type of cable is required in a wet location inside a building? A. NM-B
B. UF-B
C. SEU
D. THHN in conduit Answer: D THHN in conduit is suitable for wet locations inside buildings.
50. What is the purpose of a main bonding jumper? A. Connect branch circuits to neutral B. Bond panel neutral to grounding electrode C. Reduce voltage drop D. Increase amperage capacity Answer: B The main bonding jumper connects the neutral bus to the grounding system. 51. What is the minimum clearance for service conductors above a residential roof? A. 2 ft B. 3 ft C. 4 ft D. 5 ft Answer: B NEC requires 3 ft clearance above residential roofs for service drop conductors. 52. Which type of receptacle is required in bathrooms? A. Standard B. GFCI C. AFCI D. Twist-lock Answer: B Bathrooms require GFCI protection due to wet conditions. 53. What is the minimum wire size for a 30A branch circuit? A. #14 AWG B. #12 AWG C. #10 AWG D. #8 AWG Answer: C #10 AWG copper is rated for 30A.
59. Which breaker type protects against both arc faults and ground faults? A. Standard breaker B. GFCI C. Dual-function AFCI/GFCI D. Fuse Answer: C Dual-function breakers provide protection against arcing and ground faults. 60. What is the maximum distance a non-metallic cable can be stapled from a box? A. 6 inches B. 8 inches C. 12 inches D. 18 inches Answer: A NM cable must be secured within 12 inches of a box; some local codes require 6 inches. 61. Which type of conduit is threaded and rigid for outdoor use? A. EMT B. RMC C. FMC D. PVC Answer: B RMC (Rigid Metal Conduit) is threaded, strong, and suitable for outdoor or underground use. 62. What is the minimum size copper conductor for a 100A residential service? A. #8 AWG B. #6 AWG C. #4 AWG D. #2 AWG Answer: B NEC Table 310.15 specifies #6 AWG copper for 100A service. 63. What is the NEC maximum overcurrent protection for #12 AWG copper? A. 10A B. 15A C. 20A D. 25A
Answer: C #12 AWG copper is rated for 20A maximum.
64. Which wiring method is not allowed in wet locations? A. THWN in conduit B. NM-B C. UF-B D. EMT Answer: B NM-B (Romex) cannot be used in wet locations. 65. What is the minimum size copper equipment grounding conductor for a 60A circuit? A. #14 AWG B. #12 AWG C. #10 AWG D. #8 AWG Answer: B NEC Table 250.122 specifies #12 copper for a 60A circuit. 66. What is the purpose of a service disconnect? A. Reduce voltage B. Allow safe maintenance C. Increase amperage D. Bond neutral Answer: B A service disconnect allows power to be safely turned off for maintenance. 67. What is the maximum number of outlets on a 20A kitchen countertop branch circuit? A. 4 B. 5 C. 6 D. No specific limit Answer: D NEC does not limit outlets; the circuit load determines capacity. 68. Which device is required to protect a wet location outdoor receptacle? A. Standard breaker B. GFCI C. AFCI D. Fuse
D. 6 ft Answer: C NEC Table 110.26 specifies 4 ft for equipment over 600V.
74. Which NEC article covers grounding and bonding? A. 200 B. 210 C. 250 D. 300 Answer: C Article 250 provides rules for grounding and bonding. 75. What is the purpose of a fuse? A. Convert voltage B. Protect against overcurrent C. Ground circuits D. Measure amperage Answer: B Fuses interrupt current when it exceeds a safe level. 76. What is the standard wire color for a 240V hot leg in residential wiring? A. Black B. White C. Green D. Red Answer: D Black and red are commonly used for hot legs. 77. What is the minimum support spacing for Type NM cable? A. 3 ft B. 4.5 ft C. 6 ft D. 8 ft Answer: B NEC 334.30 requires NM cable to be supported every 4.5 ft. 78. What is the purpose of a junction box? A. Increase voltage B. Protect wire splices C. Provide grounding
D. Measure current Answer: B Junction boxes protect splices and connections from damage.
79. Which type of receptacle is required within 6 ft of a kitchen sink? A. Standard B. GFCI C. AFCI D. Twist-lock Answer: B Kitchen sinks require GFCI-protected receptacles. 80. What is the maximum voltage drop for feeders in commercial installations? A. 1% B. 3% C. 5% D. 10% Answer: C NEC recommends a maximum 5% voltage drop for feeders and branch circuits combined. 81. What is the maximum overcurrent for #10 AWG copper in free air? A. 20A B. 30A C. 35A D. 40A Answer: B #10 AWG copper is rated 30A in standard conditions. 82. Which breaker protects against arcing faults in bedrooms? A. Standard breaker B. AFCI C. GFCI D. Dual-function breaker Answer: B AFCIs prevent fires caused by arcing in wiring. 83. Which conductor is bare copper or green? A. Hot B. Neutral
C. RMC
D. PVC
Answer: C RMC is rigid and strong for industrial environments.
89. What is the standard residential service rating? A. 100A B. 200A C. 300A D. 400A Answer: B Most homes are equipped with 200A service. 90. What is the maximum spacing between outlets in a kitchen wall? A. 4 ft B. 6 ft C. 12 ft D. 15 ft Answer: C No point on a wall should be more than 6 ft from an outlet → roughly every 12 ft. 91. Which type of breaker is required in a wet location outside? A. Standard B. GFCI C. AFCI D. Fuse Answer: B Outdoor wet locations require GFCI protection. 92. What is the maximum voltage for a standard dwelling receptacle? A. 120V B. 208V C. 240V D. 277V Answer: A Standard receptacles in homes are 120V. 93. Which NEC table provides conductor ampacity? A. 310.15(B)(16)
B. 250.
C. 210.
D. 240.
Answer: A Table 310.15(B)(16) lists ampacity for conductors.
94. Which breaker type is required for kitchen circuits? A. Standard B. GFCI C. AFCI D. Dual-function Answer: B Kitchen circuits require GFCI protection. 95. What is the maximum voltage drop for branch circuits? A. 1% B. 2% C. 3% D. 5% Answer: C Branch circuits should not exceed 3% voltage drop. 96. Which wire type is rated for dry and wet locations? A. NM-B B. THHN C. UF-B D. SEU Answer: B THHN can be used in dry and wet locations inside conduit. 97. Which device measures current without breaking the circuit? A. Ammeter B. Clamp meter C. Voltmeter D. Ohmmeter Answer: B Clamp meters measure current externally. 98. Which NEC article covers service conductors? A. 210
