Missouri Journeyman Electrician Examination
Questions With Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of the National Electrical Code
(NEC)?
A. To design electrical appliances
B. To provide minimum safety standards for electrical
installations
C. To calculate electrical utility rates
D. To certify electricians
Rationale: The NEC establishes minimum safety requirements to
protect people and property from electrical hazards. It is not a design
manual or certification system but a safety standard used for
installation practices.
2. Which unit is used to measure electrical current?
A. Volt
, B. Ampere
C. Ohm
D. Watt
Rationale: Current is measured in amperes (amps), which represent
the flow of electric charge through a conductor.
3. Ohm’s Law is expressed as:
A. P = IV
B. V = IR²
C. V = IR
D. I = P/R
Rationale: Ohm’s Law defines the relationship between voltage,
current, and resistance: voltage equals current multiplied by
resistance.
4. What does a ground fault circuit interrupter (GFCI) protect
against?
A. Overvoltage
B. Short circuits
, C. Electrical shock hazards
D. Power surges
Rationale: A GFCI quickly shuts off power when it detects a difference
in current flow, preventing electric shock.
5. The color of the grounding conductor in typical U.S. wiring is:
A. White
B. Black
C. Red
D. Green or bare copper
Rationale: Grounding conductors are identified by green insulation or
are left bare to distinguish them from current-carrying conductors.
6. What is the function of a circuit breaker?
A. Increase voltage
B. Store electrical energy
C. Protect circuits from overcurrent
D. Convert AC to DC
Rationale: Circuit breakers automatically interrupt current flow when
overload or short circuit conditions occur.
, 7. Voltage is defined as:
A. Flow of electrons
B. Electrical potential difference
C. Resistance to current
D. Power consumption
Rationale: Voltage is the potential difference that drives current
through a circuit.
8. What is the standard frequency of electrical power in the United
States?
A. 50 Hz
B. 60 Hz
C. 100 Hz
D. 120 Hz
Rationale: The U.S. electrical grid operates at 60 hertz alternating
current frequency.
9. A conductor’s resistance increases when:
A. Length decreases
Questions With Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of the National Electrical Code
(NEC)?
A. To design electrical appliances
B. To provide minimum safety standards for electrical
installations
C. To calculate electrical utility rates
D. To certify electricians
Rationale: The NEC establishes minimum safety requirements to
protect people and property from electrical hazards. It is not a design
manual or certification system but a safety standard used for
installation practices.
2. Which unit is used to measure electrical current?
A. Volt
, B. Ampere
C. Ohm
D. Watt
Rationale: Current is measured in amperes (amps), which represent
the flow of electric charge through a conductor.
3. Ohm’s Law is expressed as:
A. P = IV
B. V = IR²
C. V = IR
D. I = P/R
Rationale: Ohm’s Law defines the relationship between voltage,
current, and resistance: voltage equals current multiplied by
resistance.
4. What does a ground fault circuit interrupter (GFCI) protect
against?
A. Overvoltage
B. Short circuits
, C. Electrical shock hazards
D. Power surges
Rationale: A GFCI quickly shuts off power when it detects a difference
in current flow, preventing electric shock.
5. The color of the grounding conductor in typical U.S. wiring is:
A. White
B. Black
C. Red
D. Green or bare copper
Rationale: Grounding conductors are identified by green insulation or
are left bare to distinguish them from current-carrying conductors.
6. What is the function of a circuit breaker?
A. Increase voltage
B. Store electrical energy
C. Protect circuits from overcurrent
D. Convert AC to DC
Rationale: Circuit breakers automatically interrupt current flow when
overload or short circuit conditions occur.
, 7. Voltage is defined as:
A. Flow of electrons
B. Electrical potential difference
C. Resistance to current
D. Power consumption
Rationale: Voltage is the potential difference that drives current
through a circuit.
8. What is the standard frequency of electrical power in the United
States?
A. 50 Hz
B. 60 Hz
C. 100 Hz
D. 120 Hz
Rationale: The U.S. electrical grid operates at 60 hertz alternating
current frequency.
9. A conductor’s resistance increases when:
A. Length decreases
