Electrician Wiring Methods and Materials 1 — Questions and Answers
Question 1: What type of wiring method is commonly referred to as 'Romex'?
- Armored cable (AC)
- Metal-clad cable (MC)
- Nonmetallic-sheathed cable (NM) (Correct answer)
- Underground feeder cable (UF)
Correct answer: Nonmetallic-sheathed cable (NM)
Romex is the brand name commonly used for nonmetallic-sheathed cable (NM cable) per NEC Article 334.
Question 2: What is the maximum conduit fill percentage allowed for one conductor in a conduit per NEC Chapter 9?
- 31%
- 40%
- 53% (Correct answer)
- 60%
Correct answer: 53%
NEC Chapter 9, Table 1 allows 53% conduit fill when only one conductor is installed.
Question 3: Which wiring method is required in Class I, Division 1 hazardous locations?
- NM cable
- Rigid metal conduit (RMC) or equivalent (Correct answer)
- PVC conduit
- MC cable
Correct answer: Rigid metal conduit (RMC) or equivalent
Class I, Division 1 hazardous locations require rigid metal conduit or other approved methods to contain potential ignition sources.
Question 4: What color is the outer jacket of 12 AWG NM cable (Romex)?
- White
- Yellow (Correct answer)
- Orange
- Gray
Correct answer: Yellow
12 AWG NM cable has a yellow outer jacket, while 14 AWG is white and 10 AWG is orange.
Question 5: What is the maximum support spacing for rigid metal conduit (RMC) per the NEC?
- 5 feet
- 8 feet
- 10 feet (Correct answer)
- 12 feet
Correct answer: 10 feet
The NEC requires RMC to be supported at least every 10 feet and within a certain distance of boxes and fittings.
Question 6: Which type of conduit is approved for direct burial without concrete encasement?
- EMT
- IMC
- Rigid PVC (Schedule 40) (Correct answer)
- Flexible metal conduit
Correct answer: Rigid PVC (Schedule 40)
Rigid PVC Schedule 40 and Schedule 80 conduit are approved for direct burial applications.
Electrician Wiring Methods and Materials 1
What type of wiring method is commonly referred to as 'Romex'?