CO ELECTRICAL CONTRACTOR EXAM
QUESTIONS AND CORRECT NSWERS (VERIFIED
ANSWERS) Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of an electrical circuit breaker?
A. Increase circuit voltage
B. Provide overcurrent protection
C. Improve power factor
D. Reduce conductor resistance
Correct Answer: B. Provide overcurrent protection
Rationale: A circuit breaker opens the circuit when current
exceeds its permitted value, helping protect conductors and
equipment.
2. Which unit is used to measure electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Correct Answer: C. Ampere
Rationale: Electrical current is measured in amperes (amps).
3. Which unit measures electrical resistance?
A. Ohm
B. Volt
,C. Ampere
D. Watt
Correct Answer: A. Ohm
Rationale: Resistance is measured in ohms (Ω).
4. Which formula represents Ohm's law?
A. P = I/R
B. V = IR
C. R = VI
D. I = VR
Correct Answer: B. V = IR
Rationale: Ohm's law states that voltage equals current
multiplied by resistance.
5. A 120-volt circuit has a resistance of 20 ohms. What current
flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Correct Answer: C. 6 A
Rationale: I = V/R = 120/20 = 6 amperes.
6. What is electrical power commonly measured in?
A. Watts
B. Ohms
C. Amperes
D. Hertz
,Correct Answer: A. Watts
Rationale: Electrical power is measured in watts.
7. What is the purpose of the equipment grounding
conductor?
A. Carry normal neutral current
B. Provide a low-impedance fault-current path
C. Increase circuit voltage
D. Reduce load demand
Correct Answer: B. Provide a low-impedance fault-current path
Rationale: The equipment grounding conductor provides a path
for fault current so protective devices can operate.
8. What does a neutral conductor normally carry in a single-
phase circuit?
A. Only fault current
B. Normal unbalanced or return current
C. No current under any condition
D. Only grounding current
Correct Answer: B. Normal unbalanced or return current
Rationale: In applicable circuits, the neutral carries the return
current from line-to-neutral loads.
9. What is the primary function of a service disconnect?
A. Increase service voltage
B. Disconnect power to the premises wiring
C. Regulate frequency
D. Measure energy consumption
, Correct Answer: B. Disconnect power to the premises wiring
Rationale: The service disconnect provides a means to
disconnect the premises electrical supply.
10. Which device protects a circuit from excessive current?
A. Transformer
B. Switch
C. Fuse or circuit breaker
D. Receptacle
Correct Answer: C. Fuse or circuit breaker
Rationale: Overcurrent protective devices interrupt excessive
current.
11. What is the main purpose of grounding and bonding?
A. Increase available voltage
B. Provide electrical safety and effective fault-current paths
C. Increase conductor resistance
D. Eliminate all circuit current
Correct Answer: B. Provide electrical safety and effective fault-
current paths
Rationale: Grounding and bonding help control electrical faults
and reduce shock hazards.
12. Which conductor is normally identified as the grounded
circuit conductor?
A. Equipment grounding conductor
B. Neutral conductor
QUESTIONS AND CORRECT NSWERS (VERIFIED
ANSWERS) Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of an electrical circuit breaker?
A. Increase circuit voltage
B. Provide overcurrent protection
C. Improve power factor
D. Reduce conductor resistance
Correct Answer: B. Provide overcurrent protection
Rationale: A circuit breaker opens the circuit when current
exceeds its permitted value, helping protect conductors and
equipment.
2. Which unit is used to measure electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Correct Answer: C. Ampere
Rationale: Electrical current is measured in amperes (amps).
3. Which unit measures electrical resistance?
A. Ohm
B. Volt
,C. Ampere
D. Watt
Correct Answer: A. Ohm
Rationale: Resistance is measured in ohms (Ω).
4. Which formula represents Ohm's law?
A. P = I/R
B. V = IR
C. R = VI
D. I = VR
Correct Answer: B. V = IR
Rationale: Ohm's law states that voltage equals current
multiplied by resistance.
5. A 120-volt circuit has a resistance of 20 ohms. What current
flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Correct Answer: C. 6 A
Rationale: I = V/R = 120/20 = 6 amperes.
6. What is electrical power commonly measured in?
A. Watts
B. Ohms
C. Amperes
D. Hertz
,Correct Answer: A. Watts
Rationale: Electrical power is measured in watts.
7. What is the purpose of the equipment grounding
conductor?
A. Carry normal neutral current
B. Provide a low-impedance fault-current path
C. Increase circuit voltage
D. Reduce load demand
Correct Answer: B. Provide a low-impedance fault-current path
Rationale: The equipment grounding conductor provides a path
for fault current so protective devices can operate.
8. What does a neutral conductor normally carry in a single-
phase circuit?
A. Only fault current
B. Normal unbalanced or return current
C. No current under any condition
D. Only grounding current
Correct Answer: B. Normal unbalanced or return current
Rationale: In applicable circuits, the neutral carries the return
current from line-to-neutral loads.
9. What is the primary function of a service disconnect?
A. Increase service voltage
B. Disconnect power to the premises wiring
C. Regulate frequency
D. Measure energy consumption
, Correct Answer: B. Disconnect power to the premises wiring
Rationale: The service disconnect provides a means to
disconnect the premises electrical supply.
10. Which device protects a circuit from excessive current?
A. Transformer
B. Switch
C. Fuse or circuit breaker
D. Receptacle
Correct Answer: C. Fuse or circuit breaker
Rationale: Overcurrent protective devices interrupt excessive
current.
11. What is the main purpose of grounding and bonding?
A. Increase available voltage
B. Provide electrical safety and effective fault-current paths
C. Increase conductor resistance
D. Eliminate all circuit current
Correct Answer: B. Provide electrical safety and effective fault-
current paths
Rationale: Grounding and bonding help control electrical faults
and reduce shock hazards.
12. Which conductor is normally identified as the grounded
circuit conductor?
A. Equipment grounding conductor
B. Neutral conductor
