FREE NEC Wiring Methods and Materials Questions and Answers

Question 1

An electrician is installing Type NM cable in the attic of a single-family dwelling.
The cable is run across the top of 4-inch ceiling joists.
According to NEC 2023, which of the following installations is compliant?

Accepted Answer

The cable is protected by guard strips that are at least as high as the cable.

Answer

The cable is run through bored holes in the joists that are at least 1 1/4 inches from the nearest edge.

Answer

The cable is secured directly to the top of the ceiling joists without any additional protection.

Answer

The cable is installed within 6 feet of the scuttle hole without guard strips.

Question 2

When identifying a 4 AWG or larger grounded conductor at its terminations, which of the following methods is NOT permitted by NEC 2023?

Accepted Answer

Coloring the exposed insulation green at the termination.

Answer

A continuous white outer finish along its entire length.

Answer

Three continuous white stripes along the conductor's entire length on other-than-green insulation.

Answer

Marking the insulation with white tape that encircles the conductor.

Question 3

An installer is running multiple wiring methods in a space used for environmental air-handling, otherwise known as a plenum. Which of the following wiring methods is generally permitted in this space without being enclosed in a raceway?

Accepted Answer

Type CMP (Communications Plenum) Cable

Answer

Type NM (Nonmetallic-Sheathed) Cable

Answer

Type AC (Armored) Cable

Answer

Type MC (Metal-Clad) Cable with an overall nonmetallic jacket

Question 4

What is the maximum allowable percentage of cross-sectional area that can be filled in a conduit when installing three or more conductors?

Accepted Answer

40%

Answer

31%

Answer

53%

Answer

60%

Question 5

An electrician needs to support a run of 1-inch Electrical Metallic Tubing (EMT) in a commercial building. According to NEC Article 358, the EMT must be securely fastened within what distance of each outlet box, junction box, or cabinet?

Accepted Answer

3 feet

Answer

12 inches

Answer

5 feet

Answer

10 feet

Question 6

Under which of the following conditions is Type MC (Metal-Clad) cable, with four or fewer conductors sized no larger than 10 AWG, required to be secured at intervals NOT exceeding 6 feet?

Accepted Answer

In all standard exposed installations

Answer

When fished through concealed spaces in finished buildings

Answer

When installed horizontally through wooden framing members

Answer

Only when installed in a vertical orientation

An electrician is installing Type NM cable in the attic of a single-family dwelling.The cable is run across the top of 4-inch ceiling joists.According to NEC 2023, which of the following installations is compliant?

An electrician is installing Type NM cable in the attic of a single-family dwelling.
The cable is run across the top of 4-inch ceiling joists.
According to NEC 2023, which of the following installations is compliant?