Electrical Contractor Exam (Residential)
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which type of wiring method is commonly required for residential
branch circuits?
A. Metal-clad (MC) cable
B. Nonmetallic-sheathed (NM) cable
C. Armored cable (AC)
D. Rigid metal conduit (RMC)
B. Nonmetallic-sheathed (NM) cable
Rationale: NM cable, often referred to as Romex, is widely used in
residential applications due to its ease of installation and suitability for
dry, indoor environments.
2. What is the maximum number of outlets allowed on a 15-amp,
120-volt general lighting branch circuit in a typical residence?
, A. 8
B. 10
C. 12
D. 15
C. 12
Rationale: NEC guidelines generally limit a 15-amp lighting circuit to 12
outlets to prevent overload, based on standard 180 VA per outlet.
3. Which type of grounding is typically required for a residential
electrical service?
A. Ground rod and water pipe
B. Ground rod only
C. Water pipe only
D. None
A. Ground rod and water pipe
Rationale: Residential services usually require a grounding electrode
system that includes a ground rod and, if available, a metal water pipe
to ensure effective dissipation of electrical faults.
4. A kitchen countertop receptacle must be installed so that no point
along the wall is more than how many feet from an outlet?
A. 2 feet
B. 4 feet
, C. 6 feet
D. 12 feet
C. 6 feet
Rationale: NEC requires countertop receptacles to be spaced so that no
point along the wall line is more than 24 inches (2 feet) from an outlet.
This ensures convenient access to electricity for appliances.
5. What is the minimum amperage for a dedicated dishwasher circuit
in a residential kitchen?
A. 10 amps
B. 15 amps
C. 20 amps
D. 30 amps
B. 15 amps
Rationale: Dishwashers typically require a 120-volt, 15-amp dedicated
branch circuit to handle normal operating loads safely.
6. How far above the floor must a receptacle outlet be installed in a
typical residential hallway?
A. 12 inches
B. 15 inches
C. 18 inches
D. 24 inches
, B. 15 inches
Rationale: NEC recommends mounting wall receptacles at 12–18 inches
above the floor for accessibility. Fifteen inches is commonly accepted as
standard.
7. Which type of circuit is required for bathroom receptacles?
A. 15-amp general lighting
B. 20-amp dedicated circuit
C. Shared with kitchen circuits
D. None
B. 20-amp dedicated circuit
Rationale: Bathrooms require a 20-amp branch circuit dedicated to
receptacles to handle high-power appliances like hair dryers and
prevent overload.
8. In residential wiring, what color is typically used for a grounded
(neutral) conductor?
A. Black
B. White
C. Red
D. Green
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Which type of wiring method is commonly required for residential
branch circuits?
A. Metal-clad (MC) cable
B. Nonmetallic-sheathed (NM) cable
C. Armored cable (AC)
D. Rigid metal conduit (RMC)
B. Nonmetallic-sheathed (NM) cable
Rationale: NM cable, often referred to as Romex, is widely used in
residential applications due to its ease of installation and suitability for
dry, indoor environments.
2. What is the maximum number of outlets allowed on a 15-amp,
120-volt general lighting branch circuit in a typical residence?
, A. 8
B. 10
C. 12
D. 15
C. 12
Rationale: NEC guidelines generally limit a 15-amp lighting circuit to 12
outlets to prevent overload, based on standard 180 VA per outlet.
3. Which type of grounding is typically required for a residential
electrical service?
A. Ground rod and water pipe
B. Ground rod only
C. Water pipe only
D. None
A. Ground rod and water pipe
Rationale: Residential services usually require a grounding electrode
system that includes a ground rod and, if available, a metal water pipe
to ensure effective dissipation of electrical faults.
4. A kitchen countertop receptacle must be installed so that no point
along the wall is more than how many feet from an outlet?
A. 2 feet
B. 4 feet
, C. 6 feet
D. 12 feet
C. 6 feet
Rationale: NEC requires countertop receptacles to be spaced so that no
point along the wall line is more than 24 inches (2 feet) from an outlet.
This ensures convenient access to electricity for appliances.
5. What is the minimum amperage for a dedicated dishwasher circuit
in a residential kitchen?
A. 10 amps
B. 15 amps
C. 20 amps
D. 30 amps
B. 15 amps
Rationale: Dishwashers typically require a 120-volt, 15-amp dedicated
branch circuit to handle normal operating loads safely.
6. How far above the floor must a receptacle outlet be installed in a
typical residential hallway?
A. 12 inches
B. 15 inches
C. 18 inches
D. 24 inches
, B. 15 inches
Rationale: NEC recommends mounting wall receptacles at 12–18 inches
above the floor for accessibility. Fifteen inches is commonly accepted as
standard.
7. Which type of circuit is required for bathroom receptacles?
A. 15-amp general lighting
B. 20-amp dedicated circuit
C. Shared with kitchen circuits
D. None
B. 20-amp dedicated circuit
Rationale: Bathrooms require a 20-amp branch circuit dedicated to
receptacles to handle high-power appliances like hair dryers and
prevent overload.
8. In residential wiring, what color is typically used for a grounded
(neutral) conductor?
A. Black
B. White
C. Red
D. Green
