CT Limited Electrical Journeyperson (E-4) Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
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1. What is the primary purpose of a circuit breaker in an electrical
circuit?
A. To increase the circuit voltage
B. To improve power factor
C. To interrupt current when an overcurrent condition occurs
D. To provide a continuous electrical connection
Rationale: A circuit breaker protects conductors and equipment by
opening the circuit when current exceeds a safe level. This helps prevent
overheating, equipment damage, and electrical fires.
2. Which device is specifically designed to provide protection against
ground-fault current?
,A. Transformer
B. Disconnect switch
C. Ground-fault circuit interrupter (GFCI)
D. Surge suppressor
Rationale: A GFCI monitors the current leaving and returning through a
circuit. When it detects an imbalance indicating current may be flowing
through an unintended path, it quickly disconnects power.
3. What is the standard unit used to measure electrical current?
A. Volt
B. Ohm
C. Watt
D. Ampere
Rationale: Electrical current is measured in amperes, commonly
abbreviated as amps. Voltage is measured in volts, resistance in ohms,
and power in watts.
4. What is the purpose of an equipment grounding conductor?
A. To carry normal circuit current
B. To increase circuit voltage
C. To provide a low-impedance path for fault current
D. To reduce conductor size
,Rationale: The equipment grounding conductor provides a path for fault
current back to the source so that an overcurrent protective device can
operate and disconnect the circuit.
5. Which conductor is normally identified by white or gray insulation
in a typical branch circuit?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded conductor
D. Bonding jumper
Rationale: White or gray insulation is generally used to identify the
grounded, or neutral, conductor. Identification requirements can vary
for specific applications, but this is the standard branch-circuit
identification.
6. What does Ohm's Law state?
A. P = I/R
B. V = I × R
C. I = V × R
D. R = V × I
Rationale: Ohm's Law establishes the relationship among voltage,
current, and resistance. Voltage equals current multiplied by resistance.
, 7. A 120-volt circuit has a resistance of 20 ohms. Approximately how
much current flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Rationale: Using Ohm's Law, I = V/R. Therefore, 120 ÷ 20 = 6 amperes.
8. What is the primary purpose of a disconnecting means?
A. To increase circuit capacity
B. To disconnect electrical equipment from its source of supply
C. To regulate frequency
D. To measure resistance
Rationale: A disconnecting means allows equipment to be isolated from
its electrical supply for servicing, maintenance, or emergency purposes.
9. Which type of electrical box is commonly used to contain wire
splices and connections?
A. Pull box only
B. Meter socket
C. Junction box
D. Panelboard
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary purpose of a circuit breaker in an electrical
circuit?
A. To increase the circuit voltage
B. To improve power factor
C. To interrupt current when an overcurrent condition occurs
D. To provide a continuous electrical connection
Rationale: A circuit breaker protects conductors and equipment by
opening the circuit when current exceeds a safe level. This helps prevent
overheating, equipment damage, and electrical fires.
2. Which device is specifically designed to provide protection against
ground-fault current?
,A. Transformer
B. Disconnect switch
C. Ground-fault circuit interrupter (GFCI)
D. Surge suppressor
Rationale: A GFCI monitors the current leaving and returning through a
circuit. When it detects an imbalance indicating current may be flowing
through an unintended path, it quickly disconnects power.
3. What is the standard unit used to measure electrical current?
A. Volt
B. Ohm
C. Watt
D. Ampere
Rationale: Electrical current is measured in amperes, commonly
abbreviated as amps. Voltage is measured in volts, resistance in ohms,
and power in watts.
4. What is the purpose of an equipment grounding conductor?
A. To carry normal circuit current
B. To increase circuit voltage
C. To provide a low-impedance path for fault current
D. To reduce conductor size
,Rationale: The equipment grounding conductor provides a path for fault
current back to the source so that an overcurrent protective device can
operate and disconnect the circuit.
5. Which conductor is normally identified by white or gray insulation
in a typical branch circuit?
A. Ungrounded conductor
B. Equipment grounding conductor
C. Grounded conductor
D. Bonding jumper
Rationale: White or gray insulation is generally used to identify the
grounded, or neutral, conductor. Identification requirements can vary
for specific applications, but this is the standard branch-circuit
identification.
6. What does Ohm's Law state?
A. P = I/R
B. V = I × R
C. I = V × R
D. R = V × I
Rationale: Ohm's Law establishes the relationship among voltage,
current, and resistance. Voltage equals current multiplied by resistance.
, 7. A 120-volt circuit has a resistance of 20 ohms. Approximately how
much current flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Rationale: Using Ohm's Law, I = V/R. Therefore, 120 ÷ 20 = 6 amperes.
8. What is the primary purpose of a disconnecting means?
A. To increase circuit capacity
B. To disconnect electrical equipment from its source of supply
C. To regulate frequency
D. To measure resistance
Rationale: A disconnecting means allows equipment to be isolated from
its electrical supply for servicing, maintenance, or emergency purposes.
9. Which type of electrical box is commonly used to contain wire
splices and connections?
A. Pull box only
B. Meter socket
C. Junction box
D. Panelboard
