Test Your Code IQ — November 2025

Courtesy of www.MikeHolt.com.

All questions and answers are based on the 2023 NEC.

Q1: Where _____ may be present in an agricultural building, enclosures and fittings shall have corrosion resistance properties suitable for the conditions.

a) wet dust or excessive moisture

b) corrosive gases or vapors

c) other corrosive conditions

d) any of these

Q2: Conductors in Art. 300 shall be of copper, aluminum, or copper-clad aluminum, unless otherwise specified. Copper-clad aluminum conductor material shall be _____.

a) identified for the use

b) listed

c) indicated as suitable

d) approved

Q3: Panelboards shall be mounted in cabinets, cutout boxes, or identified enclosures and where the available fault current is greater than _____, the panelboard and enclosure combination shall be evaluated for the application.

a) 5,000A

b) 10,000A

c) 12,500A

d) 22,500A

Q4: In ungrounded systems, electrical equipment, wiring, and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit from any point on the wiring system to the electrical supply source to facilitate the operation of overcurrent devices should a(an) _____ fault from a different phase occur on the wiring system.

a) isolated ground

b) second ground

c) arc

d) high impedance

Q5: Where insulated conductors are deflected within a metal wireway, the wireway shall be sized to meet the bending requirements corresponding to _____ per terminal in Table 312.6(A).

a) one wire

b) two wires

c) three wires

d) four wires

Q6: A box or conduit body shall not be required for splices and taps in _____ conductors and cables as long as the splice is made with a splicing device that is identified for the purpose. 

a) direct-buried

b) exposed

c) concealed

d) none of these

Answers:

Q1: d) any of these

Section 547.24 states, "Where wet dust, excessive moisture, corrosive gases or vapors, or other corrosive conditions could be present, equipment enclosures, boxes, conduit bodies, and fittings shall have corrosion resistance properties suitable for the conditions."

Q2: b) listed

Per Sec. 310.3(B)(4): "Copper-clad aluminum conductor material shall be listed."

Q3: b) 10,000A

As stated in Sec. 408.38, "Panelboards shall be mounted in cabinets, cutout boxes, or identified enclosures and shall be dead-front. Where the available fault current is greater than 10,000A, the panelboard and enclosure combination shall be evaluated for the application."

Q4: b) second ground

Per Sec. 250.4(B)(4): "Electrical equipment, wiring, and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit from any point on the wiring system to the electrical supply source to facilitate the operation of overcurrent devices should a second ground fault from a different phase occur on the wiring system."

Q5: a) one wire

Section 376.23(A) confirms, Where insulated conductors are deflected within a metal wireway, "dimensions corresponding to one wire per terminal in Table 312.6(A) shall apply."

Q6: a) direct-buried

As stated in Sec. 300.15(G), "A box or conduit body shall not be required for splices and taps in direct-buried conductors and cables."

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.