ICC RESIDENTIAL ELECTRICAL INSPECTOR (E1) EXAM QUESTIONS
WITH CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF
Core Domains
General Requirements and Electrical Theory
Services and Service Equipment
Branch Circuit and Feeder Requirements
Wiring Methods and Power Distribution
Devices, Lighting Fixtures, and Appliances
Grounding and Bonding
Special Occupancies and Equipment
Introduction
This examination assesses the candidate's competency in inspecting electrical
installations in one- and two-family dwellings. The test evaluates knowledge of
the International Residential Code (IRC) and National Electrical Code (NEC)
requirements for services, branch circuits, feeders, wiring methods, grounding,
and electrical equipment. Questions emphasize practical application, code
interpretation, and inspection procedures. Candidates must demonstrate critical
thinking and decision-making skills essential for ensuring safe electrical
installations. The multiple-choice format covers foundational concepts through
advanced code applications required for Residential Electrical Inspector
certification.
Section One: Questions 1–60
Question 1
What is the minimum branch circuit rating required for general lighting in
dwelling units per NEC?
A. 10 amperes
B. 15 amperes
C. 20 amperes
,D. 30 amperes
C. 20 amperes
RATIONALE: General lighting circuits in dwelling units are typically
required to be at least 20 amps to handle standard residential loads safely. This
requirement ensures adequate capacity for lighting and general-use receptacles.
Question 2
Which device is required in bathrooms of dwelling units?
A. AFCI
B. GFCI
C. Surge protector
D. Disconnect switch
B. GFCI
RATIONALE: GFCI protection is required in bathrooms to protect against
shock hazards in wet locations. All 125-volt through 250-volt receptacles
installed in bathrooms must have ground-fault circuit-interrupter protection.
Question 3
What is the maximum fill percentage for more than two conductors in a
conduit?
A. 31%
B. 40%
C. 53%
D. 60%
B. 40%
RATIONALE: Conduit fill is limited to 40% when more than two conductors
are installed in a raceway. This allows for proper heat dissipation and prevents
damage during wire pulling.
Question 4
,Which wiring method is commonly used in residential wood frame
construction?
A. EMT
B. PVC only
C. NM cable
D. Rigid steel conduit
C. NM cable
RATIONALE: Non-metallic sheathed cable (NM cable) is the most common
wiring method used in residential wood frame construction. It is cost-effective,
easy to install, and suitable for dry interior locations.
Question 5
Most residential electrical systems use what type of service voltage?
A. 120/240V
B. 208V only
C. 277/480V
D. 24V
A. 120/240V
RATIONALE: Most residential systems use split-phase 120/240V service.
This provides 120 volts for general lighting and receptacles and 240 volts for
larger appliances such as ranges and dryers.
Question 6
A multi-wire branch circuit requires:
A. Separate neutrals
B. Common disconnecting means
C. No grounding
D. Only AFCI protection
, B. Common disconnecting means
RATIONALE: Multi-wire branch circuits require simultaneous
disconnection of ungrounded conductors. This ensures that all ungrounded
conductors are de-energized when the circuit is turned off for safety.
Question 7
The equipment grounding conductor is intended to:
A. Carry normal load current
B. Provide return path for load
C. Carry fault current
D. Increase voltage stability
C. Carry fault current
RATIONALE: The equipment grounding conductor provides a safe path for
fault current to trip overcurrent devices. It does not carry current under normal
operating conditions.
Question 8
A GFCI trips when it detects:
A. Overcurrent
B. Ground fault current imbalance
C. High voltage
D. Low resistance only
B. Ground fault current imbalance
RATIONALE: GFCI devices sense imbalance between hot and neutral
conductors. When the current difference exceeds approximately 5 milliamps, the
device trips to prevent electric shock.
Question 9
Minimum burial depth for PVC conduit under a residential driveway is
typically:
WITH CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF
Core Domains
General Requirements and Electrical Theory
Services and Service Equipment
Branch Circuit and Feeder Requirements
Wiring Methods and Power Distribution
Devices, Lighting Fixtures, and Appliances
Grounding and Bonding
Special Occupancies and Equipment
Introduction
This examination assesses the candidate's competency in inspecting electrical
installations in one- and two-family dwellings. The test evaluates knowledge of
the International Residential Code (IRC) and National Electrical Code (NEC)
requirements for services, branch circuits, feeders, wiring methods, grounding,
and electrical equipment. Questions emphasize practical application, code
interpretation, and inspection procedures. Candidates must demonstrate critical
thinking and decision-making skills essential for ensuring safe electrical
installations. The multiple-choice format covers foundational concepts through
advanced code applications required for Residential Electrical Inspector
certification.
Section One: Questions 1–60
Question 1
What is the minimum branch circuit rating required for general lighting in
dwelling units per NEC?
A. 10 amperes
B. 15 amperes
C. 20 amperes
,D. 30 amperes
C. 20 amperes
RATIONALE: General lighting circuits in dwelling units are typically
required to be at least 20 amps to handle standard residential loads safely. This
requirement ensures adequate capacity for lighting and general-use receptacles.
Question 2
Which device is required in bathrooms of dwelling units?
A. AFCI
B. GFCI
C. Surge protector
D. Disconnect switch
B. GFCI
RATIONALE: GFCI protection is required in bathrooms to protect against
shock hazards in wet locations. All 125-volt through 250-volt receptacles
installed in bathrooms must have ground-fault circuit-interrupter protection.
Question 3
What is the maximum fill percentage for more than two conductors in a
conduit?
A. 31%
B. 40%
C. 53%
D. 60%
B. 40%
RATIONALE: Conduit fill is limited to 40% when more than two conductors
are installed in a raceway. This allows for proper heat dissipation and prevents
damage during wire pulling.
Question 4
,Which wiring method is commonly used in residential wood frame
construction?
A. EMT
B. PVC only
C. NM cable
D. Rigid steel conduit
C. NM cable
RATIONALE: Non-metallic sheathed cable (NM cable) is the most common
wiring method used in residential wood frame construction. It is cost-effective,
easy to install, and suitable for dry interior locations.
Question 5
Most residential electrical systems use what type of service voltage?
A. 120/240V
B. 208V only
C. 277/480V
D. 24V
A. 120/240V
RATIONALE: Most residential systems use split-phase 120/240V service.
This provides 120 volts for general lighting and receptacles and 240 volts for
larger appliances such as ranges and dryers.
Question 6
A multi-wire branch circuit requires:
A. Separate neutrals
B. Common disconnecting means
C. No grounding
D. Only AFCI protection
, B. Common disconnecting means
RATIONALE: Multi-wire branch circuits require simultaneous
disconnection of ungrounded conductors. This ensures that all ungrounded
conductors are de-energized when the circuit is turned off for safety.
Question 7
The equipment grounding conductor is intended to:
A. Carry normal load current
B. Provide return path for load
C. Carry fault current
D. Increase voltage stability
C. Carry fault current
RATIONALE: The equipment grounding conductor provides a safe path for
fault current to trip overcurrent devices. It does not carry current under normal
operating conditions.
Question 8
A GFCI trips when it detects:
A. Overcurrent
B. Ground fault current imbalance
C. High voltage
D. Low resistance only
B. Ground fault current imbalance
RATIONALE: GFCI devices sense imbalance between hot and neutral
conductors. When the current difference exceeds approximately 5 milliamps, the
device trips to prevent electric shock.
Question 9
Minimum burial depth for PVC conduit under a residential driveway is
typically:
