Journeyperson Electrician Licensing Exam:
Verified Questions and Answers | Instant PDF
Study Guide
1.What is the primary purpose of a circuit breaker in an
electrical distribution system?
A. To increase circuit voltage
B. To regulate power factor
C. To interrupt current when an overcurrent condition occurs
D. To provide a continuous connection to ground
Rationale: A circuit breaker is an overcurrent protective device
designed to open a circuit when current exceeds its rated value
for a sufficient period. This protects conductors and equipment
from excessive heating and potential fire hazards.
2. Which unit is used to measure 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.
3. According to Ohm's law, what is the current in a circuit
with a voltage of 120 volts and a resistance of 20 ohms?
,A. 2 A
B. 4 A
C. 6 A
D. 24 A
Rationale: Ohm's law states that I = E/R. Therefore, 120 V ÷ 20
Ω = 6 A.
4. Which conductor is normally used to provide the
intentional low-impedance path for fault current back to
the source?
A. Ungrounded conductor
B. Grounded conductor only
C. Equipment grounding conductor
D. Neutral bonding jumper only
Rationale: The equipment grounding conductor provides a low-
impedance path for fault current so that overcurrent protection
can operate quickly and disconnect the faulted circuit.
5. What is the electrical power consumed by a 120-volt load
drawing 10 amperes?
A. 12 W
B. 120 W
C. 1,200 W
D. 12,000 W
,Rationale: For a resistive load, power is calculated using P = E ×
I. Thus, 120 V × 10 A = 1,200 W.
6. What is the main purpose of a grounding electrode
system?
A. To increase available circuit current
B. To replace overcurrent protection
C. To connect the electrical system to earth for purposes such
as voltage stabilization and fault protection
D. To eliminate the need for equipment grounding conductors
Rationale: Grounding electrodes connect the electrical system to
earth. They help stabilize system voltage relative to earth and
provide a path for certain abnormal conditions. They do not
replace equipment grounding conductors.
7. Which type of electrical circuit provides multiple paths for
current?
A. Series circuit
B. Parallel circuit
C. Open circuit
D. Short circuit
Rationale: A parallel circuit contains multiple current paths. In a
properly functioning parallel circuit, each branch can operate
independently while receiving the circuit voltage.
, 8. In a series circuit, what happens to current throughout the
circuit?
A. It is different at every load
B. It is zero at the first load
C. The same current flows through each component
D. It doubles after every load
Rationale: A series circuit has only one path for current.
Therefore, the same current flows through every component
connected in series.
9. What is the primary function of a transformer?
A. To convert AC into DC
B. To interrupt fault current
C. To transfer electrical energy between circuits and change
voltage and current levels
D. To eliminate electrical resistance
Rationale: Transformers use electromagnetic induction to
transfer energy between windings. Depending on their
configuration, they can step voltage up or down.
10. A transformer has a 480-volt primary and a 120-volt
secondary. What type of transformer is this?
A. Isolation transformer only
B. Step-up transformer
Verified Questions and Answers | Instant PDF
Study Guide
1.What is the primary purpose of a circuit breaker in an
electrical distribution system?
A. To increase circuit voltage
B. To regulate power factor
C. To interrupt current when an overcurrent condition occurs
D. To provide a continuous connection to ground
Rationale: A circuit breaker is an overcurrent protective device
designed to open a circuit when current exceeds its rated value
for a sufficient period. This protects conductors and equipment
from excessive heating and potential fire hazards.
2. Which unit is used to measure 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.
3. According to Ohm's law, what is the current in a circuit
with a voltage of 120 volts and a resistance of 20 ohms?
,A. 2 A
B. 4 A
C. 6 A
D. 24 A
Rationale: Ohm's law states that I = E/R. Therefore, 120 V ÷ 20
Ω = 6 A.
4. Which conductor is normally used to provide the
intentional low-impedance path for fault current back to
the source?
A. Ungrounded conductor
B. Grounded conductor only
C. Equipment grounding conductor
D. Neutral bonding jumper only
Rationale: The equipment grounding conductor provides a low-
impedance path for fault current so that overcurrent protection
can operate quickly and disconnect the faulted circuit.
5. What is the electrical power consumed by a 120-volt load
drawing 10 amperes?
A. 12 W
B. 120 W
C. 1,200 W
D. 12,000 W
,Rationale: For a resistive load, power is calculated using P = E ×
I. Thus, 120 V × 10 A = 1,200 W.
6. What is the main purpose of a grounding electrode
system?
A. To increase available circuit current
B. To replace overcurrent protection
C. To connect the electrical system to earth for purposes such
as voltage stabilization and fault protection
D. To eliminate the need for equipment grounding conductors
Rationale: Grounding electrodes connect the electrical system to
earth. They help stabilize system voltage relative to earth and
provide a path for certain abnormal conditions. They do not
replace equipment grounding conductors.
7. Which type of electrical circuit provides multiple paths for
current?
A. Series circuit
B. Parallel circuit
C. Open circuit
D. Short circuit
Rationale: A parallel circuit contains multiple current paths. In a
properly functioning parallel circuit, each branch can operate
independently while receiving the circuit voltage.
, 8. In a series circuit, what happens to current throughout the
circuit?
A. It is different at every load
B. It is zero at the first load
C. The same current flows through each component
D. It doubles after every load
Rationale: A series circuit has only one path for current.
Therefore, the same current flows through every component
connected in series.
9. What is the primary function of a transformer?
A. To convert AC into DC
B. To interrupt fault current
C. To transfer electrical energy between circuits and change
voltage and current levels
D. To eliminate electrical resistance
Rationale: Transformers use electromagnetic induction to
transfer energy between windings. Depending on their
configuration, they can step voltage up or down.
10. A transformer has a 480-volt primary and a 120-volt
secondary. What type of transformer is this?
A. Isolation transformer only
B. Step-up transformer
