California Residential Electrician
Certification Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf.
1. What is the minimum branch-circuit conductor size permitted for a
20-ampere residential branch circuit according to the NEC?
A. 16 AWG copper
B. 12 AWG copper
C. 10 AWG copper
D. 14 AWG copper
Rationale: A 20-ampere branch circuit requires conductors rated at least
20 amperes. Under NEC requirements, 12 AWG copper conductors are
commonly used for 20-ampere circuits. Smaller conductors such as 14
AWG are limited to 15 amperes unless specially protected.
2. In a residential dwelling, which device is required to protect most
125-volt through 250-volt receptacles supplied by single-phase branch
circuits?
A. AFCI only
B. Surge protective device
,C. GFCI protection
D. Isolation transformer
Rationale: Ground-fault circuit interrupter (GFCI) protection is required
in locations where people may be exposed to electrical shock hazards,
such as kitchens, bathrooms, garages, outdoors, and other specified
residential areas.
3. 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 resistance during normal operation
Rationale: Equipment grounding conductors provide a safe path for
fault current back to the source, allowing overcurrent protection devices
to operate and disconnect the circuit.
4. A 120-volt, 1,800-watt space heater draws approximately how many
amperes?
A. 5 amperes
B. 10 amperes
C. 15 amperes
D. 20 amperes
Rationale: Current is calculated using the formula I = P ÷ V. 1,800 watts
÷ 120 volts = 15 amperes. This calculation determines the approximate
current draw of the heater.
,5. What is the primary function of a circuit breaker?
A. Increase electrical load capacity
B. Convert AC power to DC power
C. Interrupt excessive current flow
D. Maintain constant voltage
Rationale: Circuit breakers protect wiring and equipment by opening the
circuit when current exceeds safe levels due to overloads or short
circuits.
6. Where are tamper-resistant receptacles required in dwelling units?
A. Only garages
B. Only kitchens
C. Only outdoor locations
D. Most general-use receptacle locations
Rationale: Tamper-resistant receptacles are required in most dwelling
unit areas to reduce the risk of children inserting objects into receptacle
openings.
7. What is the purpose of an AFCI device?
A. Prevent overheating of motors
B. Protect against low voltage
C. Detect and interrupt dangerous arc faults
D. Provide additional grounding
, Rationale: Arc-fault circuit interrupters detect unintended electrical arcs
that can cause fires and disconnect the circuit before damage occurs.
8. Which conductor normally carries current back to the source in a
single-phase 120-volt circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral conductor
D. Bonding jumper
Rationale: The neutral conductor serves as the grounded conductor and
provides the return path for current in typical single-phase residential
circuits.
9. What is the maximum number of conductors generally allowed
under one terminal screw on a standard receptacle?
A. Three
B. Two
C. One
D. Unlimited
Rationale: Most device terminals are listed for a single conductor unless
specifically marked otherwise. Multiple conductors under one terminal
can create unsafe connections.
10. What is the minimum burial depth for a residential branch circuit
installed underground in PVC conduit under typical NEC conditions?
Certification Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf.
1. What is the minimum branch-circuit conductor size permitted for a
20-ampere residential branch circuit according to the NEC?
A. 16 AWG copper
B. 12 AWG copper
C. 10 AWG copper
D. 14 AWG copper
Rationale: A 20-ampere branch circuit requires conductors rated at least
20 amperes. Under NEC requirements, 12 AWG copper conductors are
commonly used for 20-ampere circuits. Smaller conductors such as 14
AWG are limited to 15 amperes unless specially protected.
2. In a residential dwelling, which device is required to protect most
125-volt through 250-volt receptacles supplied by single-phase branch
circuits?
A. AFCI only
B. Surge protective device
,C. GFCI protection
D. Isolation transformer
Rationale: Ground-fault circuit interrupter (GFCI) protection is required
in locations where people may be exposed to electrical shock hazards,
such as kitchens, bathrooms, garages, outdoors, and other specified
residential areas.
3. 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 resistance during normal operation
Rationale: Equipment grounding conductors provide a safe path for
fault current back to the source, allowing overcurrent protection devices
to operate and disconnect the circuit.
4. A 120-volt, 1,800-watt space heater draws approximately how many
amperes?
A. 5 amperes
B. 10 amperes
C. 15 amperes
D. 20 amperes
Rationale: Current is calculated using the formula I = P ÷ V. 1,800 watts
÷ 120 volts = 15 amperes. This calculation determines the approximate
current draw of the heater.
,5. What is the primary function of a circuit breaker?
A. Increase electrical load capacity
B. Convert AC power to DC power
C. Interrupt excessive current flow
D. Maintain constant voltage
Rationale: Circuit breakers protect wiring and equipment by opening the
circuit when current exceeds safe levels due to overloads or short
circuits.
6. Where are tamper-resistant receptacles required in dwelling units?
A. Only garages
B. Only kitchens
C. Only outdoor locations
D. Most general-use receptacle locations
Rationale: Tamper-resistant receptacles are required in most dwelling
unit areas to reduce the risk of children inserting objects into receptacle
openings.
7. What is the purpose of an AFCI device?
A. Prevent overheating of motors
B. Protect against low voltage
C. Detect and interrupt dangerous arc faults
D. Provide additional grounding
, Rationale: Arc-fault circuit interrupters detect unintended electrical arcs
that can cause fires and disconnect the circuit before damage occurs.
8. Which conductor normally carries current back to the source in a
single-phase 120-volt circuit?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral conductor
D. Bonding jumper
Rationale: The neutral conductor serves as the grounded conductor and
provides the return path for current in typical single-phase residential
circuits.
9. What is the maximum number of conductors generally allowed
under one terminal screw on a standard receptacle?
A. Three
B. Two
C. One
D. Unlimited
Rationale: Most device terminals are listed for a single conductor unless
specifically marked otherwise. Multiple conductors under one terminal
can create unsafe connections.
10. What is the minimum burial depth for a residential branch circuit
installed underground in PVC conduit under typical NEC conditions?
