NEC Wiring and Protection 3 — Questions and Answers
Question 1: Per NEC 210.11(C)(1), what is the minimum number of 20-ampere small-appliance branch circuits required for receptacle outlets in a dwelling kitchen?
- One
- Two (Correct answer)
- Three
- Four
Correct answer: Two
NEC 210.11(C)(1) requires two or more 20-ampere small-appliance branch circuits for kitchen, pantry, breakfast room, and dining room receptacles.
Question 2: What minimum branch circuit is required by NEC 210.11(C)(2) to supply dwelling unit laundry receptacle outlets?
- One 15-ampere circuit
- One 20-ampere circuit (Correct answer)
- Two 20-ampere circuits
- One 30-ampere circuit
Correct answer: One 20-ampere circuit
At least one 20-ampere branch circuit must supply the laundry receptacle outlets, and it must have no other outlets.
Question 3: Under NEC 210.52(A)(1), receptacles in dwelling habitable rooms must be installed so that no point along the floor line of any wall space is more than how far from a receptacle?
- 4 ft
- 6 ft (Correct answer)
- 8 ft
- 12 ft
Correct answer: 6 ft
No point along the floor line may be more than 6 ft from a receptacle, which effectively gives a maximum spacing of 12 ft.
Question 4: Dwelling kitchen countertop receptacles must be placed so that no point along the wall line is more than how far, measured horizontally, from a receptacle outlet?
- 12 in.
- 18 in.
- 24 in. (Correct answer)
- 36 in.
Correct answer: 24 in.
NEC 210.52(C)(1) limits the distance to 24 in., so receptacles end up no more than 48 in. apart.
Question 5: Which of the following is NOT a standard ampere rating for fuses and inverse time circuit breakers per NEC 240.6(A)?
- 70 A
- 75 A (Correct answer)
- 80 A
- 90 A
Correct answer: 75 A
Table 240.6(A) lists 70, 80, and 90 A as standard ratings, but 75 A is not listed.
Question 6: Per NEC 210.11(C)(3), at least one 20-ampere branch circuit must supply bathroom receptacle outlets. Which statement about that circuit is correct?
- It may also supply kitchen countertop receptacles
- It may supply other bathroom equipment if it serves only a single bathroom (Correct answer)
- It must be rated 30 A when serving more than one bathroom
- It must be a multiwire branch circuit
Correct answer: It may supply other bathroom equipment if it serves only a single bathroom
A bathroom receptacle circuit may serve only bathroom receptacles, unless it supplies a single bathroom, in which case it may also feed other equipment in that bathroom per 210.23(A) limits.
Question 7: Per NEC 210.8(A), which 125-volt through 250-volt receptacles in a dwelling unit require GFCI protection?
- Only those in bedrooms
- Those in garages and accessory buildings with floors at or below grade (Correct answer)
- Only those serving dedicated refrigerators in kitchens
- Only receptacles above 6 ft
Correct answer: Those in garages and accessory buildings with floors at or below grade
Garages and accessory buildings are among the dwelling locations listed in 210.8(A) that require GFCI protection.
