AL EL Electrical Contractor Exam Questions
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
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1. Which device is primarily used to provide overcurrent protection
for a branch circuit?
a. Disconnect switch
b. Grounding electrode
c. Circuit breaker
d. Junction box
Answer: c. Circuit breaker
Rationale: A circuit breaker is designed to interrupt current when an
overcurrent condition occurs, protecting conductors and connected
equipment from damage caused by excessive current.
2. What is the primary purpose of an equipment grounding
conductor?
,a. To carry normal operating current
b. To provide a low-impedance path for fault current
c. To increase circuit voltage
d. To reduce conductor resistance
Answer: b. 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, allowing the overcurrent
protective device to operate and disconnect the faulted circuit.
3. A 120-volt circuit has a resistance of 20 ohms. Approximately how
much current will flow?
a. 3 A
b. 6 A
c. 12 A
d. 20 A
Answer: b. 6 A
Rationale: Ohm's law states that current equals voltage divided by
resistance. Therefore, I = 120 ÷ 20 = 6 amperes.
4. What is the standard color identification for the grounded
conductor of a typical 120/240-volt system?
,a. Green
b. Red
c. White or gray
d. Orange
Answer: c. White or gray
Rationale: The grounded circuit conductor is generally identified by
white or gray insulation or equivalent approved identification. Green is
reserved for equipment grounding conductors.
5. What is the main purpose of a service disconnect?
a. To increase available fault current
b. To disconnect the premises wiring from the supply
c. To regulate branch-circuit voltage
d. To provide lighting control
Answer: b. To disconnect the premises wiring from the supply
Rationale: The service disconnect provides a means to disconnect the
building's electrical installation from the supply, allowing the
installation to be safely isolated for maintenance and emergency
conditions.
6. Which unit is used to measure electrical power?
, a. Ohm
b. Volt
c. Watt
d. Ampere
Answer: c. Watt
Rationale: Electrical power is measured in watts. In a simple DC circuit,
power can be calculated using P = E × I.
7. What is the purpose of a GFCI?
a. Prevent voltage drop
b. Detect an imbalance in current and interrupt the circuit
c. Increase circuit capacity
d. Correct low power factor
Answer: b. Detect an imbalance in current and interrupt the circuit
Rationale: A ground-fault circuit interrupter monitors current flowing
through the circuit conductors. When it detects a potentially dangerous
imbalance, it rapidly interrupts power.
8. Which type of wiring method uses individual insulated conductors
installed inside a raceway?
a. Type NM cable
b. Raceway wiring
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. Which device is primarily used to provide overcurrent protection
for a branch circuit?
a. Disconnect switch
b. Grounding electrode
c. Circuit breaker
d. Junction box
Answer: c. Circuit breaker
Rationale: A circuit breaker is designed to interrupt current when an
overcurrent condition occurs, protecting conductors and connected
equipment from damage caused by excessive current.
2. What is the primary purpose of an equipment grounding
conductor?
,a. To carry normal operating current
b. To provide a low-impedance path for fault current
c. To increase circuit voltage
d. To reduce conductor resistance
Answer: b. 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, allowing the overcurrent
protective device to operate and disconnect the faulted circuit.
3. A 120-volt circuit has a resistance of 20 ohms. Approximately how
much current will flow?
a. 3 A
b. 6 A
c. 12 A
d. 20 A
Answer: b. 6 A
Rationale: Ohm's law states that current equals voltage divided by
resistance. Therefore, I = 120 ÷ 20 = 6 amperes.
4. What is the standard color identification for the grounded
conductor of a typical 120/240-volt system?
,a. Green
b. Red
c. White or gray
d. Orange
Answer: c. White or gray
Rationale: The grounded circuit conductor is generally identified by
white or gray insulation or equivalent approved identification. Green is
reserved for equipment grounding conductors.
5. What is the main purpose of a service disconnect?
a. To increase available fault current
b. To disconnect the premises wiring from the supply
c. To regulate branch-circuit voltage
d. To provide lighting control
Answer: b. To disconnect the premises wiring from the supply
Rationale: The service disconnect provides a means to disconnect the
building's electrical installation from the supply, allowing the
installation to be safely isolated for maintenance and emergency
conditions.
6. Which unit is used to measure electrical power?
, a. Ohm
b. Volt
c. Watt
d. Ampere
Answer: c. Watt
Rationale: Electrical power is measured in watts. In a simple DC circuit,
power can be calculated using P = E × I.
7. What is the purpose of a GFCI?
a. Prevent voltage drop
b. Detect an imbalance in current and interrupt the circuit
c. Increase circuit capacity
d. Correct low power factor
Answer: b. Detect an imbalance in current and interrupt the circuit
Rationale: A ground-fault circuit interrupter monitors current flowing
through the circuit conductors. When it detects a potentially dangerous
imbalance, it rapidly interrupts power.
8. Which type of wiring method uses individual insulated conductors
installed inside a raceway?
a. Type NM cable
b. Raceway wiring
