Nevada C-2 Electrical Contractor Exam
Prep 2026 | Verified Q&As, Detailed
Rationales & NEC Formulas (Pass on Your
First Attempt!)
What is the primary purpose of an equipment grounding conductor (EGC)?
A. To carry normal load current
B. To provide a low-impedance path for fault current
C. To increase circuit voltage
D. To replace the grounded conductor
Correct 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 so that the overcurrent protective device can
operate promptly.
Which device is primarily designed to protect people from electric shock caused by
ground-fault current?
A. AFCI
B. GFCI
C. Surge protector
D. Disconnect switch
_Correct Answer: B. GFCI
Rationale: A ground-fault circuit interrupter detects an imbalance between current
leaving and returning through the circuit and interrupts the circuit when the
imbalance reaches its trip threshold.
What is the general purpose of an overcurrent protective device?
,A. Increase conductor ampacity
B. Protect conductors and equipment from excessive current
C. Reduce grounding resistance
D. Increase power factor
_Correct Answer: B. Protect conductors and equipment from excessive
current
Rationale: Fuses and circuit breakers are intended to protect conductors and
equipment from damage caused by overcurrent conditions.
A continuous load is generally calculated at what percentage of its load for
conductor and overcurrent protection sizing?
A. 50%
B. 80%
C. 100%
D. 125%
_Correct Answer: D. 125%
Rationale: A continuous load is generally treated as 125% of the continuous load
for sizing purposes under NEC requirements, subject to the applicable rules and
exceptions.
Which instrument is commonly used to measure voltage?
A. Ammeter
B. Ohmmeter
C. Voltmeter
D. Megohmmeter only
_Correct Answer: C. Voltmeter
Rationale: A voltmeter measures electrical potential difference between two points
in a circuit.
How should an ammeter normally be connected when measuring current in a
circuit?
,A. In parallel
B. In series
C. Across the grounding electrode
D. Across the circuit breaker
_Correct Answer: B. In series
Rationale: A conventional ammeter is connected in series so that circuit current
flows through the meter.
What is the unit of electrical resistance?
A. Volt
B. Ampere
C. Ohm
D. Watt
_Correct Answer: C. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Ohm's law expresses the
relationship between voltage, current, and resistance.
According to Ohm's law, current is equal to:
A. Voltage × resistance
B. Voltage ÷ resistance
C. Resistance ÷ voltage
D. Power × resistance
_Correct Answer: B. Voltage ÷ resistance
Rationale: Ohm's law is I = E/R, where I is current, E is voltage, and R is
resistance.
What is the primary function of a circuit breaker?
A. Store electrical energy
B. Interrupt current when an overcurrent condition occurs
C. Increase circuit resistance permanently
D. Convert AC to DC
, _Correct Answer: B. Interrupt current when an overcurrent condition occurs
Rationale: Circuit breakers are overcurrent protective devices that open a circuit
when specified overcurrent conditions occur.
Which conductor normally carries the unbalanced current in a multiwire branch
circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral or grounded conductor
D. Bonding jumper only
_Correct Answer: C. Neutral or grounded conductor
Rationale: In a multiwire branch circuit, the grounded conductor carries the
unbalanced portion of the current from the ungrounded conductors.
What is the purpose of bonding metal parts of an electrical system?
A. To increase operating voltage
B. To establish electrical continuity and facilitate fault-current clearing
C. To reduce conductor ampacity
D. To eliminate the need for overcurrent protection
_Correct Answer: B. To establish electrical continuity and facilitate fault-
current clearing
Rationale: Bonding connects conductive parts together so that a low-impedance
fault-current path is available when required.
Which formula is used to calculate electrical power in a basic DC circuit?
A. P = E × I
B. P = E ÷ I
C. P = I ÷ E
D. P = R ÷ E
_Correct Answer: A. P = E × I
Rationale: Electrical power in watts equals voltage multiplied by current.
Prep 2026 | Verified Q&As, Detailed
Rationales & NEC Formulas (Pass on Your
First Attempt!)
What is the primary purpose of an equipment grounding conductor (EGC)?
A. To carry normal load current
B. To provide a low-impedance path for fault current
C. To increase circuit voltage
D. To replace the grounded conductor
Correct 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 so that the overcurrent protective device can
operate promptly.
Which device is primarily designed to protect people from electric shock caused by
ground-fault current?
A. AFCI
B. GFCI
C. Surge protector
D. Disconnect switch
_Correct Answer: B. GFCI
Rationale: A ground-fault circuit interrupter detects an imbalance between current
leaving and returning through the circuit and interrupts the circuit when the
imbalance reaches its trip threshold.
What is the general purpose of an overcurrent protective device?
,A. Increase conductor ampacity
B. Protect conductors and equipment from excessive current
C. Reduce grounding resistance
D. Increase power factor
_Correct Answer: B. Protect conductors and equipment from excessive
current
Rationale: Fuses and circuit breakers are intended to protect conductors and
equipment from damage caused by overcurrent conditions.
A continuous load is generally calculated at what percentage of its load for
conductor and overcurrent protection sizing?
A. 50%
B. 80%
C. 100%
D. 125%
_Correct Answer: D. 125%
Rationale: A continuous load is generally treated as 125% of the continuous load
for sizing purposes under NEC requirements, subject to the applicable rules and
exceptions.
Which instrument is commonly used to measure voltage?
A. Ammeter
B. Ohmmeter
C. Voltmeter
D. Megohmmeter only
_Correct Answer: C. Voltmeter
Rationale: A voltmeter measures electrical potential difference between two points
in a circuit.
How should an ammeter normally be connected when measuring current in a
circuit?
,A. In parallel
B. In series
C. Across the grounding electrode
D. Across the circuit breaker
_Correct Answer: B. In series
Rationale: A conventional ammeter is connected in series so that circuit current
flows through the meter.
What is the unit of electrical resistance?
A. Volt
B. Ampere
C. Ohm
D. Watt
_Correct Answer: C. Ohm
Rationale: Electrical resistance is measured in ohms (Ω). Ohm's law expresses the
relationship between voltage, current, and resistance.
According to Ohm's law, current is equal to:
A. Voltage × resistance
B. Voltage ÷ resistance
C. Resistance ÷ voltage
D. Power × resistance
_Correct Answer: B. Voltage ÷ resistance
Rationale: Ohm's law is I = E/R, where I is current, E is voltage, and R is
resistance.
What is the primary function of a circuit breaker?
A. Store electrical energy
B. Interrupt current when an overcurrent condition occurs
C. Increase circuit resistance permanently
D. Convert AC to DC
, _Correct Answer: B. Interrupt current when an overcurrent condition occurs
Rationale: Circuit breakers are overcurrent protective devices that open a circuit
when specified overcurrent conditions occur.
Which conductor normally carries the unbalanced current in a multiwire branch
circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral or grounded conductor
D. Bonding jumper only
_Correct Answer: C. Neutral or grounded conductor
Rationale: In a multiwire branch circuit, the grounded conductor carries the
unbalanced portion of the current from the ungrounded conductors.
What is the purpose of bonding metal parts of an electrical system?
A. To increase operating voltage
B. To establish electrical continuity and facilitate fault-current clearing
C. To reduce conductor ampacity
D. To eliminate the need for overcurrent protection
_Correct Answer: B. To establish electrical continuity and facilitate fault-
current clearing
Rationale: Bonding connects conductive parts together so that a low-impedance
fault-current path is available when required.
Which formula is used to calculate electrical power in a basic DC circuit?
A. P = E × I
B. P = E ÷ I
C. P = I ÷ E
D. P = R ÷ E
_Correct Answer: A. P = E × I
Rationale: Electrical power in watts equals voltage multiplied by current.
