Electrical Code Review | High-Yield Practice Questions with
Detailed Explanations, Wiring Methods, Electrical Theory, Load
Calculations, Safety Standards, Blueprint Reading, Real-World
Jobsite Scenarios, and Complete Review to Pass the Journeyman
Electrician Licensing Exam on the First Attempt
1. What is the primary function of a circuit breaker?
• A) To measure electrical current
• B) To protect the electrical circuit from overloads and short circuits
• C) To convert AC to DC
• D) To store electrical energy
Correct Option: B
Rationale: A circuit breaker is designed to automatically interrupt the flow of electricity
in a circuit when it detects an overload or a fault, thereby protecting the circuit and
preventing potential hazards.
2. What is the purpose of grounding in electrical systems?
• A) To provide a path for fault current to dissipate safely
• B) To increase voltage in a circuit
• C) To store electrical energy
• D) To measure power consumption
Correct Option: A
Rationale: Grounding provides a safe path for fault current to travel back to the ground,
reducing the risk of electric shock and equipment damage.
3. In residential electrical systems, what is the standard voltage supplied?
• A) 120 volts
• B) 240 volts
• C) 380 volts
• D) 480 volts
Correct Option: B
Rationale: In residential systems, the standard voltage is typically 120 volts for general
outlets and 240 volts for larger appliances such as dryers and ovens.
, 4. Which of the following is a code requirement for connecting electrical panels?
• A) Panels must be located within 10 feet of each other
• B) All connections must be made using proper wire sizes and types
• C) Only copper wire can be used
• D) Panels do not need to be accessible
Correct Option: B
Rationale: Proper wire sizing and types are critical to ensure safety and compliance
with electrical codes. This prevents overheating and ensures reliability.
5. What is the function of a resistor in a circuit?
• A) To limit the flow of current
• B) To increase voltage
• C) To store electrical charge
• D) To convert energy types
Correct Option: A
Rationale: A resistor is used to limit the flow of electrical current in a circuit, helping to
protect other components and manage voltage levels.
6. Which component is used to convert alternating current (AC) to direct current
(DC)?
• A) Transformer
• B) Inductor
• C) Rectifier
• D) Capacitor
Correct Option: C
Rationale: A rectifier converts AC to DC by allowing current to flow only in one
direction, making it useful for powering DC devices.
7. What device measures electric current?
• A) Voltmeter
• B) Ammeter
• C) Ohmmeter
• D) Wattmeter