IEC Basic Electrical Standards 2

Question 1

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

Accepted Answer

12 inches

Answer

NEC Table 300.5 requires RMC to be buried at least 12 inches under residential driveways.

Question 2

According to the NEC, what color must the grounding conductor be identified by?

Accepted Answer

Green or bare

Answer

NEC 250.119 requires equipment grounding conductors to be green, green with yellow stripe, or bare.

Question 3

A 20-ampere, 125-volt receptacle outlet is required in which of the following bathroom locations per NEC?

Accepted Answer

Within 3 feet of the sink basin

Answer

NEC 210.52(D) requires at least one receptacle within 3 feet of each sink basin in bathrooms.

Question 4

What is the maximum voltage drop recommended by the NEC for branch circuits serving general loads?

Accepted Answer

3%

Answer

NEC 210.19(A) informational note recommends keeping branch circuit voltage drop to 3% or less.

Question 5

Under the NEC, which conductor insulation type is rated for use in wet locations?

Accepted Answer

THW

Answer

THW insulation is rated for use in both dry and wet locations, unlike THHN which is dry-location only.

IEC - Independent Electrical Contractors Practice Test