Missouri Journeyman Electrician Exam Newest
(2026 Update) Actual Practice Questions – Set
100 Most Common Exam Questions And
Answers In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. A 120V branch circuit supplies general lighting in a dwelling unit. According
to NEC standards, what is the minimum rating of the branch circuit?
A. 10A
B. 15A
C. 20A
D. 30A
Answer: B ✓ [B. 15A]
*Rationale: A 15-amp branch circuit is the minimum permitted for general
lighting in dwelling units under NEC standards.
2. What is the maximum number of 12 AWG copper conductors allowed in a
standard 2-inch conduit fill (no adjustments applied)?
A. 9
B. 16
C. 25
D. 32
Answer: B ✓ [B. 16]
*Rationale: Conduit fill limits based on NEC Chapter 9 allow approximately 16
conductors of 12 AWG in 2-inch conduit depending on insulation type.
, 3. A GFCI device is primarily designed to protect against:
A. Overvoltage
B. Short circuits
C. Ground faults
D. Arc faults only
Answer: C ✓ [C. Ground faults]
*Rationale: GFCI devices detect imbalance between hot and neutral conductors
to prevent ground-fault shock hazards.
4. What is the minimum burial depth for a 120V residential branch circuit in
PVC conduit under a driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: C ✓ [C. 18 inches]
*Rationale: NEC requires at least 18 inches cover for residential PVC under
driveways.
5. Which color is typically used for grounded neutral conductors?
A. Green
B. White
C. Red
D. Black
Answer: B ✓ [B. White]
*Rationale: White or gray insulation identifies grounded neutral conductors per
NEC rules.
, 6. A 240V single-phase load draws 24 amps. What is the minimum wire size
(copper) required?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: C ✓ [C. 10 AWG]
*Rationale: 10 AWG copper is rated for 30 amps, safely covering a 24A load.
7. Which device protects against arc faults in residential wiring?
A. AFCI
B. GFCI
C. MCB
D. Disconnect switch
Answer: A ✓ [A. AFCI]
*Rationale: Arc Fault Circuit Interrupters detect dangerous arcing conditions that
may cause fires.
8. The purpose of a bonding jumper is to:
A. Increase voltage
B. Reduce resistance in grounding paths
C. Limit current flow
D. Isolate circuits
Answer: B ✓ [B. Reduce resistance in grounding paths]
*Rationale: Bonding ensures low impedance path for fault current to trip
protection devices.
, 9. What is the standard voltage of a residential split-phase system in the U.S.?
A. 120V
B. 208V
C. 240V
D. 480V
Answer: C ✓ [C. 240V]
*Rationale: Residential services provide 120/240V split-phase power.
10.A 20A receptacle circuit must use a minimum conductor size of:
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: B ✓ [B. 12 AWG]
*Rationale: 12 AWG copper is rated for 20 amps per NEC standards.
11.What is the primary purpose of a circuit breaker?
A. Increase load capacity
B. Provide overcurrent protection
C. Store electrical energy
D. Reduce voltage drop
Answer: B ✓ [B. Provide overcurrent protection]
*Rationale: Circuit breakers interrupt excessive current to protect wiring and
equipment.
12.In a residential panel, the neutral bar is typically:
A. Energized
B. Isolated in subpanels
(2026 Update) Actual Practice Questions – Set
100 Most Common Exam Questions And
Answers In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. A 120V branch circuit supplies general lighting in a dwelling unit. According
to NEC standards, what is the minimum rating of the branch circuit?
A. 10A
B. 15A
C. 20A
D. 30A
Answer: B ✓ [B. 15A]
*Rationale: A 15-amp branch circuit is the minimum permitted for general
lighting in dwelling units under NEC standards.
2. What is the maximum number of 12 AWG copper conductors allowed in a
standard 2-inch conduit fill (no adjustments applied)?
A. 9
B. 16
C. 25
D. 32
Answer: B ✓ [B. 16]
*Rationale: Conduit fill limits based on NEC Chapter 9 allow approximately 16
conductors of 12 AWG in 2-inch conduit depending on insulation type.
, 3. A GFCI device is primarily designed to protect against:
A. Overvoltage
B. Short circuits
C. Ground faults
D. Arc faults only
Answer: C ✓ [C. Ground faults]
*Rationale: GFCI devices detect imbalance between hot and neutral conductors
to prevent ground-fault shock hazards.
4. What is the minimum burial depth for a 120V residential branch circuit in
PVC conduit under a driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Answer: C ✓ [C. 18 inches]
*Rationale: NEC requires at least 18 inches cover for residential PVC under
driveways.
5. Which color is typically used for grounded neutral conductors?
A. Green
B. White
C. Red
D. Black
Answer: B ✓ [B. White]
*Rationale: White or gray insulation identifies grounded neutral conductors per
NEC rules.
, 6. A 240V single-phase load draws 24 amps. What is the minimum wire size
(copper) required?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: C ✓ [C. 10 AWG]
*Rationale: 10 AWG copper is rated for 30 amps, safely covering a 24A load.
7. Which device protects against arc faults in residential wiring?
A. AFCI
B. GFCI
C. MCB
D. Disconnect switch
Answer: A ✓ [A. AFCI]
*Rationale: Arc Fault Circuit Interrupters detect dangerous arcing conditions that
may cause fires.
8. The purpose of a bonding jumper is to:
A. Increase voltage
B. Reduce resistance in grounding paths
C. Limit current flow
D. Isolate circuits
Answer: B ✓ [B. Reduce resistance in grounding paths]
*Rationale: Bonding ensures low impedance path for fault current to trip
protection devices.
, 9. What is the standard voltage of a residential split-phase system in the U.S.?
A. 120V
B. 208V
C. 240V
D. 480V
Answer: C ✓ [C. 240V]
*Rationale: Residential services provide 120/240V split-phase power.
10.A 20A receptacle circuit must use a minimum conductor size of:
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 8 AWG
Answer: B ✓ [B. 12 AWG]
*Rationale: 12 AWG copper is rated for 20 amps per NEC standards.
11.What is the primary purpose of a circuit breaker?
A. Increase load capacity
B. Provide overcurrent protection
C. Store electrical energy
D. Reduce voltage drop
Answer: B ✓ [B. Provide overcurrent protection]
*Rationale: Circuit breakers interrupt excessive current to protect wiring and
equipment.
12.In a residential panel, the neutral bar is typically:
A. Energized
B. Isolated in subpanels
