AL EL-S Electrical Specialty Contractor
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary purpose of a circuit breaker in an electrical
circuit?
A. To increase voltage
B. To provide illumination
C. To protect conductors from overcurrent
D. To reduce electrical resistance
Answer: C. To protect conductors from overcurrent
Rationale: A circuit breaker opens the circuit when current exceeds a safe
level, protecting conductors and equipment from overheating and
potential fire hazards.
, 2. Which unit is used to measure electrical current?
A. Volt
B. Ohm
C. Watt
D. Ampere
Answer: D. Ampere
Rationale: The ampere, commonly called an amp, is the standard unit used
to measure electric current.
3. Which instrument is normally used to measure voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Wattmeter
Answer: B. Voltmeter
Rationale: A voltmeter measures electrical potential difference, or voltage,
between two points.
4. What is the electrical resistance of a conductor measured in?
A. Amperes
B. Volts
,C. Ohms
D. Watts
Answer: C. Ohms
Rationale: The ohm is the SI unit of electrical resistance.
5. Which formula represents Ohm's law?
A. P = I/R
B. E = I × R
C. R = E × I
D. I = E × R
Answer: B. E = I × R
Rationale: Ohm's law states that voltage (E) equals current (I) multiplied
by resistance (R).
6. What is the purpose of an equipment grounding conductor?
A. To carry normal load current
B. To increase circuit voltage
C. To provide a path for fault current
D. To reduce the size of the neutral conductor
Answer: C. To provide a path for fault current
, Rationale: The equipment grounding conductor provides a low-impedance
path for fault current so protective devices can operate promptly.
7. Which conductor normally carries the return current in a single-phase,
line-to-neutral circuit?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper
D. Grounding electrode conductor
Answer: B. Neutral conductor
Rationale: In a typical line-to-neutral circuit, the grounded neutral
conductor carries the current returning from the load.
8. What is the main purpose of electrical bonding?
A. To increase circuit resistance
B. To establish electrical continuity between conductive parts
C. To eliminate the need for overcurrent protection
D. To increase conductor ampacity
Answer: B. To establish electrical continuity between conductive parts
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary purpose of a circuit breaker in an electrical
circuit?
A. To increase voltage
B. To provide illumination
C. To protect conductors from overcurrent
D. To reduce electrical resistance
Answer: C. To protect conductors from overcurrent
Rationale: A circuit breaker opens the circuit when current exceeds a safe
level, protecting conductors and equipment from overheating and
potential fire hazards.
, 2. Which unit is used to measure electrical current?
A. Volt
B. Ohm
C. Watt
D. Ampere
Answer: D. Ampere
Rationale: The ampere, commonly called an amp, is the standard unit used
to measure electric current.
3. Which instrument is normally used to measure voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Wattmeter
Answer: B. Voltmeter
Rationale: A voltmeter measures electrical potential difference, or voltage,
between two points.
4. What is the electrical resistance of a conductor measured in?
A. Amperes
B. Volts
,C. Ohms
D. Watts
Answer: C. Ohms
Rationale: The ohm is the SI unit of electrical resistance.
5. Which formula represents Ohm's law?
A. P = I/R
B. E = I × R
C. R = E × I
D. I = E × R
Answer: B. E = I × R
Rationale: Ohm's law states that voltage (E) equals current (I) multiplied
by resistance (R).
6. What is the purpose of an equipment grounding conductor?
A. To carry normal load current
B. To increase circuit voltage
C. To provide a path for fault current
D. To reduce the size of the neutral conductor
Answer: C. To provide a path for fault current
, Rationale: The equipment grounding conductor provides a low-impedance
path for fault current so protective devices can operate promptly.
7. Which conductor normally carries the return current in a single-phase,
line-to-neutral circuit?
A. Equipment grounding conductor
B. Neutral conductor
C. Bonding jumper
D. Grounding electrode conductor
Answer: B. Neutral conductor
Rationale: In a typical line-to-neutral circuit, the grounded neutral
conductor carries the current returning from the load.
8. What is the main purpose of electrical bonding?
A. To increase circuit resistance
B. To establish electrical continuity between conductive parts
C. To eliminate the need for overcurrent protection
D. To increase conductor ampacity
Answer: B. To establish electrical continuity between conductive parts
