Protection From Physical Damage Practice Questions

B. 300.6

The rule sits two section numbers below where the previous edition printed it, because listing and reconditioned equipment were pulled to the front of the article and everything behind them slid down. All three wrong choices are real sections in the 2026 book, which is what makes them expensive. Read a section title before you read its text.

NEC 2026 300.6

A. Limitations by voltage and temperature, with a subsection on damaged conductors and wiring methods

The number many candidates still associate with physical damage is neither vacant nor off topic. It caps a wiring method by voltage and by temperature, and this cycle it picked up a subsection whose heading carries the word damaged. Nothing printed on the page warns you that you are one section short of what you wanted.

NEC 2026 300.4, 300.4(C)

C. 300.4(C), which calls for the conductors and wiring method to be replaced

Two rules in the same article sound alike and answer opposite questions. One keeps damage away from a wiring method that is still sound, and the other says what to do with one already ruined by overheating, fire, corrosive influences or water. A stem describing a cable that has already been cooked or soaked is answered from the second.

NEC 2026 300.4(C), 300.6

D. 1/16 inch

The figure is 1.6 mm, printed as 1/16 inch, and the plate has to be of a length and width that covers the area of the wiring. The section also accepts a listed and marked steel plate thinner than that where it gives equal or better protection against nail or screw penetration, so a thinner plate is not automatically wrong if it carries that marking.

NEC 2026 300.6(A)(1)

A. Rigid metal conduit, intermediate metal conduit, rigid PVC conduit, RTRC and electrical metallic tubing

The exception is built around methods a nail or a screw is not going to get through. It reaches the four rigid raceway types and the tubing, and it reads the same way in the notch paragraph directly below it. A cable is never on that list, which is why the plate question is nearly always a cable question.

NEC 2026 300.6(A)(1)

D. Before the building finish is applied

The section states the sequencing directly, and that is the only ordering instruction in the whole subsection, which is what makes it worth carrying. A plate added after the finish cannot be verified and cannot be seated against the notch. The plate thickness is the same 1/16 inch used at bored holes.

NEC 2026 300.6(A)(2)

C. Listed bushings or listed grommets covering all metal edges, fastened in the opening before the cable goes in

At a metal framing member the hazard is the cut edge of the opening rather than a screw driven through the finish later, so the fix is a bushing rather than a plate. The section calls for it to be securely fastened in the opening prior to installation of the cable, which is a sequencing point an item can test on its own. The cable article repeats the requirement and adds that the grommets stay in place.

NEC 2026 300.6(B)(1), 334.17

B. A steel sleeve, steel plate or steel clip not less than 1/16 inch thick

The first paragraph handles the cut edge of the punched hole and this one handles the fastener that arrives later. Two hazards, two consecutive paragraphs, and an item will hand you one condition and see whether you answer with the other. The thickness figure matches the one used at bored holes and notches.

NEC 2026 300.6(B)(2)

D. Fishing the cables between access points

The parallel-run subsection carries three exceptions, and this one is the allowance for retrofits in finished buildings and in finished panels for prefabricated buildings. It does not lift the clearance from the face of the member as a general matter, so open framing on new work gets no relief from it. Decide which of the three exceptions the stem is actually describing.

NEC 2026 300.6(D)

C. 1-1/2 inches

The figure is 38 mm, printed as 1-1/2 inches, and the reasoning sits in the informational note: roof work done after the electrical goes in drives screws down through the deck. The same subsection bars wiring methods from concealed locations in metal-corrugated sheet decking roofs. If your notes on this rule say corrugated, they describe the narrower version the 2026 edition replaced.

NEC 2026 300.6(E)

A. Rigid metal conduit and intermediate metal conduit with listed steel or malleable iron fittings and boxes

The first exception names the two heavy threaded raceways and puts a condition on the fittings and boxes as well. Tubing is not on this list even though tubing is excused from the plate requirement at bored holes, which is a useful reminder that each exception has its own membership. Two further exceptions cover concrete over corrugated decking and wiring encased in concrete.

NEC 2026 300.6(E)

B. 2 inches, measured from the top of the corrugated roofing

The second exception is a dimension and a datum, and an item will change the datum while leaving the number alone. Fifty millimeters prints as 2 inches, and the measurement runs from the top of the corrugated roofing rather than from any part of the wiring. A third exception separately permits wiring in concealed locations where it is encased in concrete of the same thickness.

NEC 2026 300.6(E)

C. A 1/16 inch steel plate, sleeve or equivalent, or 1-1/4 inches of free space for the full length of the groove

The groove rule covers wallboard, siding, paneling, carpeting and similar finishes, and it takes either armor over the wiring or depth away from the fastener. Free space works because a screw long enough to reach the wallboard is not long enough to reach the cable. The same exceptions for rigid raceways and for listed thin plates apply here as at the bored hole.

NEC 2026 300.6(F)

A. An identified fitting with a smoothly rounded insulating surface, a listed metal fitting with smoothly rounded edges, identified insulating material, or an integral threaded hub with a rounded entry

The subsection turns on conductor size rather than raceway size, and the threshold is 4 AWG and larger insulated circuit conductors. It gives four ways to satisfy the rule and only one of them is the plastic bushing most people picture. It reaches raceways entering a cabinet, a box, an enclosure or another raceway.

NEC 2026 300.6(G)

D. No, and any insulating fitting or material used has to carry a temperature rating not less than the insulation rating of the installed conductors

A plastic bushing keeps conductors off an edge, but it is not a mechanical connection and the section says so directly. The same paragraph attaches a temperature condition to the insulating fitting, which is the half of the rule candidates skip. Both statements sit in one short block of text under the fittings subsection.

NEC 2026 300.6(G)

B. A listed expansion or deflection fitting, or other approved means

This subsection is short and easy to miss, since it sits at the end of the physical damage section rather than in the article for the raceway type. It names buildings, bridges, parking garages and other structures and it takes a listed fitting or another approved means. Thermal movement along a straight run is a different problem handled in the individual raceway articles.

NEC 2026 300.6(H)

C. The tubing list says severe physical damage while the nonmetallic tubing list says physical damage

One word separates the two lists and it changes which installations are barred outright. The metal tubing is kept out only where damage would be severe, while the nonmetallic tubing is kept out of locations subject to physical damage generally. An item that describes a moderate exposure and offers both raceways is testing exactly this.

NEC 2026 358.12, 362.12

D. Schedule 80 PVC conduit, Schedule 80 elbows and listed fittings for PVC conduit

The uses-not-permitted list bars the conduit where subject to physical damage but points back at a permitted use that carves out the heavy-wall version. So the answer is not that the method is barred, it is that only one schedule of it qualifies. An informational note adds that listed PVC fittings suit both schedules.

NEC 2026 352.12(C), 352.10(K)

A. Where subject to physical damage

The list runs to seven entries and physical damage is the last of them, sitting with wet locations, storage battery rooms, hazardous locations and burial. This is the trap on top of the trap: where the method article keeps a method out of the location, adding a plate does not rescue it. Read the uses-not-permitted list before you decide what protection would fix the run.

NEC 2026 348.12

B. Rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC, RTRC marked XW or other approved means, extending at least 6 inches above the floor

The general damage rule sends framing questions to Article 300, but the floor penetration is written into the cable article itself, so a candidate who tabbed only the Article 300 section has to go looking. The extension is 150 mm, printed as 6 inches. The same paragraph separately calls for a bushing or adapter where the cable enters and exits the raceway.

NEC 2026 334.15(B)(1)

D. Guard strips at least as high as the cable

The attic rule turns on how people get into the space, and permanent stairs or a permanent ladder mean the run across the framing gets guard strips. The same subsection reaches cable run across the face of rafters or studding within 7 feet of the floor or horizontal surface. Cable run parallel to the sides of the members needs neither guard strips nor a running board.

NEC 2026 320.23(A)(1), 320.23(B)

C. Within 6 feet of the nearest edge of the scuttle hole or attic entrance

Where nobody can walk into the space, the code protects only the part of the run a person could reach from the opening, and 1.8 m prints as 6 feet. The distance is measured from the nearest edge of the opening rather than from its center. Two consecutive paragraphs, one condition, two very different amounts of guard strip.

NEC 2026 320.23(A)(2)

B. Rigid metal conduit, intermediate metal conduit, Schedule 80 PVC, RTRC-XW, electrical metallic tubing or cable armor

The grounding electrode conductor carries its own damage rule inside Article 250 and does not borrow the Chapter 3 one, so the protective methods named are raceways and armor rather than plates. The rule turns on two facts at once, the size of the conductor and whether it is exposed. A scenario about a grounding electrode conductor is never answered from the Article 300 damage section.

NEC 2026 250.64(B)(2)

A. No, but it is buried or otherwise protected where it is subject to physical damage

Grounding electrode conductors and grounding electrode bonding jumpers in contact with the earth are released from the cover requirements that govern ordinary underground work, in both the general article and the one for higher voltages. What is not released is the damage question, which follows the conductor underground. So a stem that puts a bonding jumper across a driveway is asking about the second half of that sentence.

NEC 2026 250.64(B), 300.7(A)

A. Electrical metallic tubing, rigid metal conduit, intermediate metal conduit, RTRC-XW, Schedule 80 PVC conduit or equivalent

Underground installations carry their own damage subdivision, which is why a stem about a riser out of a trench is not answered from the framing section. A neighboring paragraph sets how far the protection runs, from the required cover depth below grade to at least 8 feet above finished grade. Notice that Schedule 40 PVC is off this list while Schedule 80 is on it.

NEC 2026 300.7(D)(4), 300.7(D)(1)