Test Your Code IQ — December 2025

Courtesy of www.MikeHolt.com.

All questions and answers are based on the 2023 NEC.

Q1: Where lighting outlets are installed for an interior stairway with _____ risers between floor levels, there shall be a listed wall-mounted control device at each floor level and at each landing level that includes a stairway entry to control the lighting outlets.

a) three or more

b) four or more

c) six or more

d) any number of

Q2: The installation and use of all boxes and conduit bodies used as outlet, device, junction, or pull boxes, depending on their use, and handhole enclosures, are covered within _____.

a) Art. 110

b) Art. 200

c) Art. 300

d) Art. 314

Q3: Motor branch-circuit short-circuit and ground-fault protection and motor overload protection _____ be combined in a single protective device where the rating of the device provides the required overload protection.

a) shall be permitted to

b) shall not be permitted to

c) shall

d) shall not

Q4: Ground-fault protection of equipment shall be provided for solidly grounded wye electrical services of more than 150V to ground but not exceeding 1,000V phase-to-phase for each service disconnecting means rated _____ or more.

a) 1,000A

b) 1,500A

c) 2,000A

d) 2,500A

Q5: PV system DC circuit conductors that rely on other than color coding for polarity identification shall be identified by an approved permanent marking means such as _____.

a) labeling

b) sleeving

c) shrink-tubing

d) any of these

Q6: PV system DC circuit conductor marking means for nonsolidly grounded positive conductors shall include imprinted plus signs (+) or the word POSITIVE or POS durably marked on insulation of a color other than _____.

a) green

b) white

c) gray

d) all of these

Answers:

Q1: c) six or more

Section 210.70(A)(2)(3) requires, "Where lighting outlets are installed for an interior stairway with six or more risers between floor levels, there shall be a wall switch or listed wall-mounted control device at each floor level and at each landing level that includes a stairway entry to control the lighting outlets."

Q2: d) Article 314

Per Sec. 314.1: "This article covers the installation and use of all boxes and conduit bodies used as outlet, device, junction, or pull boxes, depending on their use, and handhole enclosures."

Q3: a) shall be permitted to

As stated in Sec. 430.55, "Motor branch-circuit short-circuit and ground-fault protection and motor overload protection shall be permitted to be combined in a single protective device where the rating of the device provides the overload protection specified in Sec. 430.32."

Q4: a) 1,000A

Per Sec. 230.95(A): "GFPE shall be provided for solidly grounded wye electrical services of more than 150V to ground but not exceeding 1,000V phase-to-phase for each service disconnect rated 1,000A or more."

Q5: d) any of these

Section 690.31(B)(2)(a) states, "Conductors that rely on other than color coding for polarity identification shall be identified by an approved permanent marking means such as labeling, sleeving, or shrink-tubing that is suitable for the conductor size."

Q6: d) all of these

According to Sec. 690.31(B)(2)(b), "The permanent marking means for nonsolidly grounded positive conductors shall include imprinted plus signs (+) or the word POSITIVE or POS durably marked on insulation of a color other than green, white, or gray."

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