GFCI and AFCI rules have changed a lot over the last few code cycles, which is exactly why they show up on the exam. A rule you learned a few years ago might not be the current one.
Every question here is based on the 2023 NEC. Some states are on a different edition, so check which one your exam uses.
-
Question 1 of 15
Which subsection covers GFCI protection for receptacles in the listed locations of other-than-dwelling occupancies?
Show answerHide answer
Answer: A. 210.8(B)
NEC 210.8(B) covers GFCI protection for receptacles in listed locations in other-than-dwelling occupancies. Dwelling unit receptacles are in 210.8(A), and specific appliances in either occupancy are in 210.8(D).
-
Question 2 of 15
Which protection is primarily intended for personnel shock hazards?
Show answerHide answer
Answer: A. GFCI
GFCI protection is intended to reduce the risk of electric shock, while AFCI protection is intended to reduce the risk of fire from arcing faults.
-
Question 3 of 15
Which device protects against ground-fault shock hazards but does NOT itself provide the circuit's overcurrent protection?
Show answerHide answer
Answer: A. A GFCI receptacle
A GFCI receptacle provides personnel protection from ground-fault shock hazards but has no overcurrent protection, so the circuit still needs its breaker or fuse. A GFCI circuit breaker is different: it combines the GFCI function with overcurrent protection.
-
Question 4 of 15
A receptacle installed in a dwelling unit bathroom is generally required to have:
Show answerHide answer
Answer: A. GFCI protection
Bathrooms are a required GFCI location under NEC 210.8(A) because the primary hazard is shock near water. This is a common trap in an AFCI-focused set.
-
Question 5 of 15
In a dwelling unit, a bedroom has a shower stall. A 120-volt, 15-amp receptacle in the bedroom is 4 ft from the outside edge of the shower stall. What protection is required?
Show answerHide answer
Answer: A. GFCI protection because of the shower stall, plus AFCI protection for the bedroom circuit
210.8(A)(10) requires GFCI protection for dwelling receptacles within 6 ft of the outside edge of a bathtub or shower stall, regardless of the room. The bedroom circuit also needs AFCI protection under 210.12(B).
-
Question 6 of 15
Which NEC section MOST directly addresses AFCI requirements for dwelling units?
Show answerHide answer
Answer: A. 210.12(B)
NEC 2023 210.12(B) covers AFCI protection for dwelling unit branch circuits supplying outlets or devices in the listed areas. In the 2020 NEC this was 210.12(A); in 2023, 210.12(A) covers the means of protection.
-
Question 7 of 15
Which dwelling-unit receptacle requires GFCI protection under 210.8(A)?
Show answerHide answer
Answer: A. A 125-volt, 15-amp receptacle in a detached accessory building
210.8(A)(2) covers garages and accessory buildings of dwelling units. Bedrooms, living rooms, and hallways aren't in the 210.8(A) list, so their receptacles need GFCI protection only if another item applies, such as being within 6 ft of a sink. (Those circuits generally need AFCI protection under 210.12(B) instead.)
-
Question 8 of 15
Which is the BEST one-line exam takeaway for AFCI requirements?
Show answerHide answer
Answer: A. In dwelling units, 120V, 10-, 15- and 20-A branch circuits supplying outlets or devices in many listed areas require AFCI protection
NEC 2023 210.12(B) requires AFCI protection for 120-volt, single-phase, 10-, 15-, and 20-ampere branch circuits supplying outlets or devices in many listed dwelling unit areas.
-
Question 9 of 15
Which device opens the circuit when ground-fault current reaches roughly 4 to 6 mA, to protect people from shock?
Show answerHide answer
Answer: A. GFCI device
A Class A GFCI must trip when ground-fault current reaches 6 mA and must not trip below 4 mA. About 5 mA is the nominal figure often quoted, not an exact universal trip point. Tripping at milliamp levels is what makes a GFCI personnel protection rather than equipment protection.
-
Question 10 of 15
Which circuit below is outside the scope of NEC 210.12(B)?
Show answerHide answer
Answer: D. A 240V, 30A circuit supplying an electric dryer receptacle
NEC 2023 210.12(B) applies to 120-volt, single-phase, 10-, 15-, and 20-ampere branch circuits supplying outlets or devices in listed dwelling unit areas. A 240-volt, 30-ampere dryer circuit is outside that scope.
-
Question 11 of 15
In a dwelling unit kitchen, which receptacles require GFCI protection under NEC 2023?
Show answerHide answer
Answer: A. All kitchen receptacles
NEC 2023 210.8(A)(6) requires GFCI protection for all 125-volt through 250-volt receptacles in dwelling unit kitchens supplied by single-phase branch circuits rated 150 volts or less to ground, not only those serving the countertop. The 2020 NEC limited kitchen GFCI protection to receptacles serving countertop surfaces.
-
Question 12 of 15
A receptacle circuit in a dwelling laundry area needs both AFCI and GFCI protection. Which single device at the panel can provide both?
Show answerHide answer
Answer: A. A dual-function AFCI/GFCI circuit breaker
A dual-function AFCI/GFCI breaker provides both protections. A combination-type AFCI provides arc-fault protection only: "combination" means it detects both series and parallel arcing, not that it includes GFCI. Laundry areas are in both 210.8(A)(11) and 210.12(B).
-
Question 13 of 15
A pool pump motor at a dwelling is supplied by a 120-volt, 20-amp branch circuit. What protection does its outlet generally require?
Show answerHide answer
Answer: A. GFCI protection
NEC 2023 680.21(C) requires GFCI protection for outlets supplying pool pump motors, whether by receptacle or direct (hardwired) connection. 680.5 sets the type: Class A GFCI for circuits rated 150 volts or less to ground, and special-purpose GFCI (SPGFCI) for higher-voltage circuits. A typical 120-volt residential pump circuit needs Class A GFCI protection.
-
Question 14 of 15
A dwelling unit branch circuit supplies outlets in a bedroom. Which is a permitted method of providing AFCI protection?
Show answerHide answer
Answer: A. A listed combination-type AFCI at the origin of the branch circuit, protecting the entire branch circuit
NEC 2023 210.12(A)(1) permits a listed combination-type AFCI installed to provide protection of the entire branch circuit, typically an AFCI breaker at the panel. 210.12(A) lists other permitted means as well. An upsized standard breaker or a fuse provides no arc-fault protection.
-
Question 15 of 15
What condition does a GFCI detect in order to trip?
Show answerHide answer
Answer: A. A difference between the current on the ungrounded and grounded conductors
A GFCI compares the current on the ungrounded (hot) and grounded (neutral) conductors. When they differ by more than its trip threshold (about 4-6 mA for a Class A GFCI), current is leaving the intended path, and the device trips. The imbalance alone doesn't tell you what caused the fault.
Want more? Electrician Practice has 1,100+ practice questions with explanations.
If you missed kitchen GFCI questions, review the 2023 changes. The rules got broader than they used to be.
Know the difference: GFCI protects people from shock, AFCI protects against fires from arcing.
Want more questions like these?
Electrician Practice has 1,100+ practice questions with explanations, timed practice exams, and weak-area drills.