CO Journeyman Electrician Exam
Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of an overcurrent protective device
such as a circuit breaker?
A. To increase circuit voltage
B. To stabilize frequency
C. To protect conductors and equipment from excessive current
D. To improve power factor
Rationale: An overcurrent protective device opens the circuit when
current exceeds a safe level. This helps prevent conductor
overheating, insulation damage, equipment failure, and fire.
2. According to Ohm’s law, what current flows through a 20-ohm
resistance connected to a 120-volt source?
,A. 0.17 A
B. 2 A
C. 6 A
D. 24 A
Rationale: Ohm’s law states that I = E/R. Therefore, I = 120 ÷ 20 = 6
amperes.
3. What is the purpose of the equipment grounding conductor?
A. To carry normal circuit current
B. To increase available voltage
C. To reduce conductor resistance
D. To provide a low-impedance path for fault current
Rationale: The equipment grounding conductor provides a conductive
path for fault current back to the source. This allows the overcurrent
device to operate promptly during a ground fault.
4. Which conductor is normally identified by white or gray
insulation?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded circuit conductor
D. Switched grounding conductor
,Rationale: The grounded circuit conductor, commonly called the
neutral, is generally identified by white or gray insulation. Green or
bare conductors are generally reserved for grounding purposes.
5. A 120-volt circuit supplies a 1,800-watt load. Approximately how
much current does the load draw?
A. 7.5 A
B. 10 A
C. 15 A
D. 20 A
Rationale: Current is calculated by dividing power by voltage. I = 1,800
÷ 120 = 15 amperes.
6. What is the main function of a disconnecting means?
A. To increase circuit capacity
B. To regulate current
C. To disconnect electrical equipment from its source of supply
D. To reduce conductor temperature
Rationale: A disconnecting means provides a way to disconnect
equipment or circuits from their supply. It is important for servicing,
maintenance, and safety.
, 7. Which wiring method uses individual insulated conductors
installed inside a raceway?
A. NM cable
B. UF cable
C. Conduit and conductors
D. SE cable
Rationale: Raceway systems such as EMT, IMC, RMC, and PVC conduit
contain individual conductors pulled through the raceway. This differs
from cable assemblies, which contain multiple conductors within an
overall jacket.
8. What is the unit of electrical resistance?
A. Volt
B. Ampere
C. Watt
D. Ohm
Rationale: Resistance is measured in ohms (Ω). Voltage is measured in
volts, current in amperes, and power in watts.
9. What happens to current in a series circuit if resistance increases
while voltage remains constant?
Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of an overcurrent protective device
such as a circuit breaker?
A. To increase circuit voltage
B. To stabilize frequency
C. To protect conductors and equipment from excessive current
D. To improve power factor
Rationale: An overcurrent protective device opens the circuit when
current exceeds a safe level. This helps prevent conductor
overheating, insulation damage, equipment failure, and fire.
2. According to Ohm’s law, what current flows through a 20-ohm
resistance connected to a 120-volt source?
,A. 0.17 A
B. 2 A
C. 6 A
D. 24 A
Rationale: Ohm’s law states that I = E/R. Therefore, I = 120 ÷ 20 = 6
amperes.
3. What is the purpose of the equipment grounding conductor?
A. To carry normal circuit current
B. To increase available voltage
C. To reduce conductor resistance
D. To provide a low-impedance path for fault current
Rationale: The equipment grounding conductor provides a conductive
path for fault current back to the source. This allows the overcurrent
device to operate promptly during a ground fault.
4. Which conductor is normally identified by white or gray
insulation?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded circuit conductor
D. Switched grounding conductor
,Rationale: The grounded circuit conductor, commonly called the
neutral, is generally identified by white or gray insulation. Green or
bare conductors are generally reserved for grounding purposes.
5. A 120-volt circuit supplies a 1,800-watt load. Approximately how
much current does the load draw?
A. 7.5 A
B. 10 A
C. 15 A
D. 20 A
Rationale: Current is calculated by dividing power by voltage. I = 1,800
÷ 120 = 15 amperes.
6. What is the main function of a disconnecting means?
A. To increase circuit capacity
B. To regulate current
C. To disconnect electrical equipment from its source of supply
D. To reduce conductor temperature
Rationale: A disconnecting means provides a way to disconnect
equipment or circuits from their supply. It is important for servicing,
maintenance, and safety.
, 7. Which wiring method uses individual insulated conductors
installed inside a raceway?
A. NM cable
B. UF cable
C. Conduit and conductors
D. SE cable
Rationale: Raceway systems such as EMT, IMC, RMC, and PVC conduit
contain individual conductors pulled through the raceway. This differs
from cable assemblies, which contain multiple conductors within an
overall jacket.
8. What is the unit of electrical resistance?
A. Volt
B. Ampere
C. Watt
D. Ohm
Rationale: Resistance is measured in ohms (Ω). Voltage is measured in
volts, current in amperes, and power in watts.
9. What happens to current in a series circuit if resistance increases
while voltage remains constant?
