Journeyman Electrician Theory
Examination Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which of the following is the primary function of a transformer?
A. Convert direct current to alternating current
B. Change voltage levels
C. Increase resistance
D. Store electrical energy
Rationale: Transformers are used to step up or step down voltage in
an AC circuit.
2. Ohm’s Law is expressed as:
A. V = I × R
, B. P = V × I
C. V = I × R
D. I = V ÷ P
Rationale: Ohm’s Law defines the relationship between voltage (V),
current (I), and resistance (R) in a circuit.
3. A conductor with low resistivity is preferred because it:
A. Produces more heat
B. Allows current to flow easily
C. Increases voltage drop
D. Reduces power efficiency
Rationale: Low resistivity materials, like copper, allow electricity to
flow with minimal resistance.
4. The term “grounding” in electrical systems refers to:
A. Connecting devices to a circuit breaker
B. Connecting electrical systems to the earth
C. Insulating electrical wires
D. Increasing voltage capacity
Rationale: Grounding provides a safe path for fault current to the
earth to prevent shock or fire.
,5. The unit of electrical power is:
A. Ampere
B. Watt
C. Ohm
D. Volt
Rationale: Power (P) is measured in watts, calculated as P = V × I.
6. What is the main purpose of a circuit breaker?
A. Store energy
B. Interrupt excessive current flow
C. Step down voltage
D. Measure current
Rationale: Circuit breakers protect circuits by automatically
interrupting current flow during overloads or short circuits.
7. In a three-phase system, the voltage between any two lines is called:
A. Line-to-neutral voltage
B. Line-to-line voltage
C. Phase voltage
D. Ground voltage
Rationale: Line-to-line voltage is the voltage measured between any
two of the three phases.
, 8. An insulator is best described as a material that:
A. Resists the flow of electric current
B. Conducts electricity efficiently
C. Increases voltage
D. Stores charge
Rationale: Insulators, such as rubber or plastic, prevent current flow
and are used to protect against shock.
9. A device that converts mechanical energy into electrical energy is a:
A. Transformer
B. Generator
C. Rectifier
D. Capacitor
Rationale: Generators produce electricity by mechanical motion
through electromagnetic induction.
10. A capacitor in an AC circuit:
A. Stores direct current
B. Stores energy in an electric field
C. Resists all current flow
D. Measures voltage
Examination Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which of the following is the primary function of a transformer?
A. Convert direct current to alternating current
B. Change voltage levels
C. Increase resistance
D. Store electrical energy
Rationale: Transformers are used to step up or step down voltage in
an AC circuit.
2. Ohm’s Law is expressed as:
A. V = I × R
, B. P = V × I
C. V = I × R
D. I = V ÷ P
Rationale: Ohm’s Law defines the relationship between voltage (V),
current (I), and resistance (R) in a circuit.
3. A conductor with low resistivity is preferred because it:
A. Produces more heat
B. Allows current to flow easily
C. Increases voltage drop
D. Reduces power efficiency
Rationale: Low resistivity materials, like copper, allow electricity to
flow with minimal resistance.
4. The term “grounding” in electrical systems refers to:
A. Connecting devices to a circuit breaker
B. Connecting electrical systems to the earth
C. Insulating electrical wires
D. Increasing voltage capacity
Rationale: Grounding provides a safe path for fault current to the
earth to prevent shock or fire.
,5. The unit of electrical power is:
A. Ampere
B. Watt
C. Ohm
D. Volt
Rationale: Power (P) is measured in watts, calculated as P = V × I.
6. What is the main purpose of a circuit breaker?
A. Store energy
B. Interrupt excessive current flow
C. Step down voltage
D. Measure current
Rationale: Circuit breakers protect circuits by automatically
interrupting current flow during overloads or short circuits.
7. In a three-phase system, the voltage between any two lines is called:
A. Line-to-neutral voltage
B. Line-to-line voltage
C. Phase voltage
D. Ground voltage
Rationale: Line-to-line voltage is the voltage measured between any
two of the three phases.
, 8. An insulator is best described as a material that:
A. Resists the flow of electric current
B. Conducts electricity efficiently
C. Increases voltage
D. Stores charge
Rationale: Insulators, such as rubber or plastic, prevent current flow
and are used to protect against shock.
9. A device that converts mechanical energy into electrical energy is a:
A. Transformer
B. Generator
C. Rectifier
D. Capacitor
Rationale: Generators produce electricity by mechanical motion
through electromagnetic induction.
10. A capacitor in an AC circuit:
A. Stores direct current
B. Stores energy in an electric field
C. Resists all current flow
D. Measures voltage
