Ohio Electrical Contractor Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Which organization publishes the National Electrical Code (NEC)?
A. OSHA
B. IEEE
C. NFPA
D. ANSI
Rationale: The National Electrical Code (NEC) is published by the
National Fire Protection Association (NFPA). The NEC is updated every
three years and establishes minimum standards for safe electrical
installations throughout the United States.
2. The primary purpose of the NEC is to:
A. Guarantee electrical system efficiency
B. Reduce installation costs
C. Provide practical safeguarding of persons and property from
,electrical hazards
D. Standardize utility rates
Rationale: The NEC's stated purpose is the practical safeguarding of
persons and property from hazards arising from the use of electricity.
It is not intended as a design specification or instruction manual.
3. A branch circuit is defined as the conductors between the:
A. Service drop and service equipment
B. Transformer and meter
C. Final overcurrent device protecting the circuit and the outlets
D. Main disconnect and utility transformer
Rationale: Article 100 defines a branch circuit as the circuit conductors
between the final overcurrent device protecting the circuit and the
outlets served.
4. Conductors shall generally be sized based on:
A. Fixture color
B. Voltage only
C. Ampacity
D. Number of switches
,Rationale: Conductors are selected primarily according to their
ampacity, ensuring they can safely carry the intended load without
overheating.
5. Copper conductors generally have:
A. Higher resistance than aluminum
B. Lower conductivity than aluminum
C. Higher conductivity than aluminum
D. The same conductivity as steel
Rationale: Copper offers higher electrical conductivity and lower
resistance than aluminum, allowing it to carry more current for a
given conductor size.
6. Equipment grounding conductors are primarily intended to:
A. Carry normal load current
B. Increase circuit voltage
C. Provide an effective fault-current path
D. Improve lighting efficiency
Rationale: Equipment grounding conductors provide a low-impedance
path that allows overcurrent devices to clear ground faults rapidly.
, 7. Grounding and bonding differ because bonding:
A. Increases voltage
B. Ensures electrical continuity between conductive parts
C. Eliminates overcurrent devices
D. Replaces grounding electrodes
Rationale: Bonding joins conductive parts together to establish
electrical continuity and maintain the ability to conduct fault current
safely.
8. Which overcurrent device automatically opens a circuit under
overload conditions?
A. Switch
B. Receptacle
C. Circuit breaker
D. Junction box
Rationale: Circuit breakers detect excessive current and automatically
interrupt the circuit to prevent overheating and fire hazards.
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. Which organization publishes the National Electrical Code (NEC)?
A. OSHA
B. IEEE
C. NFPA
D. ANSI
Rationale: The National Electrical Code (NEC) is published by the
National Fire Protection Association (NFPA). The NEC is updated every
three years and establishes minimum standards for safe electrical
installations throughout the United States.
2. The primary purpose of the NEC is to:
A. Guarantee electrical system efficiency
B. Reduce installation costs
C. Provide practical safeguarding of persons and property from
,electrical hazards
D. Standardize utility rates
Rationale: The NEC's stated purpose is the practical safeguarding of
persons and property from hazards arising from the use of electricity.
It is not intended as a design specification or instruction manual.
3. A branch circuit is defined as the conductors between the:
A. Service drop and service equipment
B. Transformer and meter
C. Final overcurrent device protecting the circuit and the outlets
D. Main disconnect and utility transformer
Rationale: Article 100 defines a branch circuit as the circuit conductors
between the final overcurrent device protecting the circuit and the
outlets served.
4. Conductors shall generally be sized based on:
A. Fixture color
B. Voltage only
C. Ampacity
D. Number of switches
,Rationale: Conductors are selected primarily according to their
ampacity, ensuring they can safely carry the intended load without
overheating.
5. Copper conductors generally have:
A. Higher resistance than aluminum
B. Lower conductivity than aluminum
C. Higher conductivity than aluminum
D. The same conductivity as steel
Rationale: Copper offers higher electrical conductivity and lower
resistance than aluminum, allowing it to carry more current for a
given conductor size.
6. Equipment grounding conductors are primarily intended to:
A. Carry normal load current
B. Increase circuit voltage
C. Provide an effective fault-current path
D. Improve lighting efficiency
Rationale: Equipment grounding conductors provide a low-impedance
path that allows overcurrent devices to clear ground faults rapidly.
, 7. Grounding and bonding differ because bonding:
A. Increases voltage
B. Ensures electrical continuity between conductive parts
C. Eliminates overcurrent devices
D. Replaces grounding electrodes
Rationale: Bonding joins conductive parts together to establish
electrical continuity and maintain the ability to conduct fault current
safely.
8. Which overcurrent device automatically opens a circuit under
overload conditions?
A. Switch
B. Receptacle
C. Circuit breaker
D. Junction box
Rationale: Circuit breakers detect excessive current and automatically
interrupt the circuit to prevent overheating and fire hazards.
