Test Your Code IQ — January 2026

Courtesy of www.MikeHolt.com.

All questions and answers are based on the 2023 NEC.

Q1: Receptacles shall not be installed inside the tub or shower or within a zone measured 3 ft horizontally from any outside edge of the bathtub or shower stall. Receptacles installed where a hydromassage bathtub is _____ with the supply receptacle accessible only through a service access opening shall be permitted.

a) rated 20A or less

b) rated 30A or less

c) six or more

d) less than 125V

Q2: The minimum ampacity of conductors feeding a group of welders shall be based on the individual currents determined in Sec. 630.11(A) as the sum of _____ of the two largest welders, plus 85% of the third largest welder, plus 70% of the fourth largest welder, plus 60% of all remaining welders.

a) 100%

b) 125%

c) 150%

d) 175%

Q3: A circuit breaker with a _____ rating, such as 120V/240V or 480Y/277V can be used on a solidly grounded circuit where the nominal voltage of any conductor to ground does not exceed the lower of the two values, and the nominal voltage between any two conductors does not exceed the higher value.

a) straight

b) slash

c) high

d) low

Q4: Where the opening to an outlet, junction, or switch point is less than 8 in. in any dimension, the length of free conductor of each conductor, spliced or unspliced, shall extend at least _____ outside the opening of the enclosure.

a) 1 in.

b) 3 in.

c) 6 in.

d) 12 in.

Q5: Metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal _____ are permitted as grounding electrodes. 

a) gas pipe

b) fire-sprinkler pipe

c) water pipe

d) none of these

Q6: Type NM cable on a wall of an unfinished basement installed in a listed raceway shall have a _____ installed at the point where the cable enters the raceway.

a) suitable insulating bushing or adapter

b) sealing fitting

c) bonding bushing

d) junction box

Answers:

Q1: c) cord-and plug-connected

Section 406.9(C) Exception No. 1 asserts, "Receptacles installed in accordance with Sec. 680.73 shall be permitted."

Q2: a) 100%

Per Sec. 630.11(B): "Minimum conductor ampacity shall be based on the individual currents determined in Sec. 630.11(A) as the sum of 100% of the two largest welders, plus 85% of the third largest welder, plus 70% of the fourth largest welder, plus 60% of all remaining welders."

Q3: b) slash

According to Sec. 240.85, "A circuit breaker with a slash rating, such as 120/240V or 277/480V, shall be permitted to be applied in a solidly grounded circuit where the nominal voltage of any conductor to ground does not exceed the lower of the two values," and the nominal voltage between any two conductors does not exceed the higher value.

Q4: b) 3 in.

Per Sec. 300.14: "Where the opening to an outlet, junction, or switch point is less than 8 in. in any dimension, each conductor shall be long enough to extend at least 3 in. outside the opening."

Q5:  c) water pipe

Section 250.52(A)(8) confirms, "Other local metal underground systems or structures such as piping systems, underground tanks, and underground metal well casings that are not bonded to a metal water pipe." 

Q6: a) suitable insulating bushing or adapter

According to Sec. 334.15(C), Type NM cable on a wall of an unfinished basement installed in a listed raceway shall have a suitable insulating bushing or adapter installed at the point where the cable enters the raceway.

These materials are provided by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.