CO Journeyman Electrician Exam
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. During the installation of a branch circuit in a commercial building, a
journeyman electrician must determine the minimum ampacity of
conductors supplying a continuous load. If a load operates
continuously for three hours or more and has a calculated load of
32 amperes, what minimum conductor ampacity is generally
required before considering applicable adjustment or correction
factors?
A. 32 amperes
B. 36 amperes
C. 40 amperes
D. 48 amperes
Rationale: Continuous loads are generally calculated at 125% of the
continuous load. Therefore, 32 amperes × 125% equals 40 amperes
minimum required ampacity.
2. Which statement best describes the primary purpose of an
equipment grounding conductor in an electrical installation?
,A. To carry normal load current back to the source
B. To increase the voltage available to connected equipment
C. To eliminate the need for overcurrent protection
D. To provide a low-impedance path for fault current and facilitate
operation of protective devices
Rationale: The equipment grounding conductor provides a fault-current
path that helps ensure sufficient current flows during a ground fault to
operate the fuse or circuit breaker promptly.
3. A 120-volt, single-phase branch circuit supplies a resistive load rated
at 1,800 watts. Ignoring power factor and conductor losses,
approximately how much current does the load draw?
A. 10 amperes
B. 12 amperes
C. 15 amperes
D. 18 amperes
Rationale: Current is calculated using I = P ÷ V. Therefore, 1,800 watts ÷
120 volts equals 15 amperes.
4. What is the principal reason that conductors installed in locations
with high ambient temperatures may require ampacity correction?
A. High temperatures reduce circuit voltage
B. High temperatures increase conductor insulation thickness
C. High temperatures reduce the ability of conductors to dissipate heat
,safely
D. High temperatures eliminate inductive reactance
Rationale: Conductors generate heat when carrying current, and
elevated ambient temperatures reduce their ability to dissipate that
heat, potentially requiring ampacity correction.
5. When selecting an overcurrent protective device for a branch
circuit, what is its primary safety function?
A. To regulate the power factor of the circuit
B. To maintain constant voltage during utility fluctuations
C. To disconnect the circuit when excessive current could damage
conductors or equipment
D. To prevent all voltage drop in branch-circuit conductors
Rationale: Fuses and circuit breakers protect conductors and equipment
by interrupting excessive current caused by overloads or faults.
6. Which type of electrical fault occurs when an energized conductor
unintentionally contacts another conductor or a grounded
conductive surface, creating a low-resistance current path?
A. Open circuit
B. Voltage drop
C. Inductive coupling
D. Short circuit or ground fault
Rationale: A short circuit or ground fault creates an unintended low-
impedance path that can result in extremely high fault current.
, 7. A transformer has a primary voltage of 480 volts and a secondary
voltage of 120 volts. Assuming an ideal transformer, which
statement is correct?
A. The transformer is a step-up transformer
B. The secondary current must always be lower than primary current
C. The transformer is a step-down transformer
D. The transformer converts AC directly into DC
Rationale: Because the secondary voltage is lower than the primary
voltage, the transformer reduces voltage and is classified as a step-
down transformer.
8. What is the purpose of bonding electrically conductive metal parts
that are likely to become energized?
A. To increase the resistance of the electrical system
B. To isolate metal components from the grounding system
C. To establish electrical continuity and an effective fault-current path
D. To allow metal parts to carry normal neutral current
Rationale: Bonding connects conductive components together and to
the grounding system so fault current has an effective path for
operating protective devices.
9. Which instrument is most appropriate for measuring insulation
resistance at a higher test voltage than an ordinary multimeter?
A. Clamp-on ammeter
B. Wattmeter
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. During the installation of a branch circuit in a commercial building, a
journeyman electrician must determine the minimum ampacity of
conductors supplying a continuous load. If a load operates
continuously for three hours or more and has a calculated load of
32 amperes, what minimum conductor ampacity is generally
required before considering applicable adjustment or correction
factors?
A. 32 amperes
B. 36 amperes
C. 40 amperes
D. 48 amperes
Rationale: Continuous loads are generally calculated at 125% of the
continuous load. Therefore, 32 amperes × 125% equals 40 amperes
minimum required ampacity.
2. Which statement best describes the primary purpose of an
equipment grounding conductor in an electrical installation?
,A. To carry normal load current back to the source
B. To increase the voltage available to connected equipment
C. To eliminate the need for overcurrent protection
D. To provide a low-impedance path for fault current and facilitate
operation of protective devices
Rationale: The equipment grounding conductor provides a fault-current
path that helps ensure sufficient current flows during a ground fault to
operate the fuse or circuit breaker promptly.
3. A 120-volt, single-phase branch circuit supplies a resistive load rated
at 1,800 watts. Ignoring power factor and conductor losses,
approximately how much current does the load draw?
A. 10 amperes
B. 12 amperes
C. 15 amperes
D. 18 amperes
Rationale: Current is calculated using I = P ÷ V. Therefore, 1,800 watts ÷
120 volts equals 15 amperes.
4. What is the principal reason that conductors installed in locations
with high ambient temperatures may require ampacity correction?
A. High temperatures reduce circuit voltage
B. High temperatures increase conductor insulation thickness
C. High temperatures reduce the ability of conductors to dissipate heat
,safely
D. High temperatures eliminate inductive reactance
Rationale: Conductors generate heat when carrying current, and
elevated ambient temperatures reduce their ability to dissipate that
heat, potentially requiring ampacity correction.
5. When selecting an overcurrent protective device for a branch
circuit, what is its primary safety function?
A. To regulate the power factor of the circuit
B. To maintain constant voltage during utility fluctuations
C. To disconnect the circuit when excessive current could damage
conductors or equipment
D. To prevent all voltage drop in branch-circuit conductors
Rationale: Fuses and circuit breakers protect conductors and equipment
by interrupting excessive current caused by overloads or faults.
6. Which type of electrical fault occurs when an energized conductor
unintentionally contacts another conductor or a grounded
conductive surface, creating a low-resistance current path?
A. Open circuit
B. Voltage drop
C. Inductive coupling
D. Short circuit or ground fault
Rationale: A short circuit or ground fault creates an unintended low-
impedance path that can result in extremely high fault current.
, 7. A transformer has a primary voltage of 480 volts and a secondary
voltage of 120 volts. Assuming an ideal transformer, which
statement is correct?
A. The transformer is a step-up transformer
B. The secondary current must always be lower than primary current
C. The transformer is a step-down transformer
D. The transformer converts AC directly into DC
Rationale: Because the secondary voltage is lower than the primary
voltage, the transformer reduces voltage and is classified as a step-
down transformer.
8. What is the purpose of bonding electrically conductive metal parts
that are likely to become energized?
A. To increase the resistance of the electrical system
B. To isolate metal components from the grounding system
C. To establish electrical continuity and an effective fault-current path
D. To allow metal parts to carry normal neutral current
Rationale: Bonding connects conductive components together and to
the grounding system so fault current has an effective path for
operating protective devices.
9. Which instrument is most appropriate for measuring insulation
resistance at a higher test voltage than an ordinary multimeter?
A. Clamp-on ammeter
B. Wattmeter
