CEA Wiring Methods and Materials 3

Question 1

Intermediate metal conduit (IMC) has walls that are thinner than rigid metal conduit (RMC). Which statement about IMC is correct?

Accepted Answer

IMC is approved for all the same applications as RMC

Answer

NEC 342 lists IMC as suitable for all environments where RMC is permitted, including concrete encasement and direct burial.

Question 2

What is the required minimum burial depth for rigid metal conduit (RMC) installed under a residential driveway?

Accepted Answer

12 inches

Answer

NEC Table 300.5 requires RMC and IMC to be buried at least 6 inches under residential driveways.

Question 3

Type UF cable installed as a direct-buried feeder to an outbuilding must be buried at least how deep under a one-family dwelling's yard?

Accepted Answer

18 inches

Answer

NEC Table 300.5 requires direct-buried Type UF cable to be at least 24 inches deep, reduced to 18 inches under a dwelling's yard in some applications; the standard general requirement is 24 inches.

Question 4

Which fitting must be used where electrical metallic tubing (EMT) enters a box to protect conductors from the sharp edge of the tubing?

Accepted Answer

Connector with insulating throat or separate bushing

Answer

NEC 358.46 requires fittings that protect conductors at EMT terminations, typically connectors with an insulating throat.

Question 5

Non-metallic sheathed cable (NM-B) is permitted to be installed in which of the following locations?

Accepted Answer

Dry locations in wood-frame residential structures

Answer

NM-B cable is restricted to dry locations and is most commonly used in wood-frame, one- and two-family dwellings per NEC 334.10.

(CEA) Certified Electrical Apprentice Practice Test

(CEA) Certified Electrical Apprentice Practice Test

CEA Wiring Methods and Materials 3