Master Electrician Practice Exam

What is the minimum depth required for a rigid metal conduit crossing under a public driveway at a retail shopping center?

1. 18 inches

2. 24 inches

3. 30 inches

4. 36 inches

The correct answer is: 24 inches

The minimum depth required for rigid metal conduit crossing under a public driveway is indeed 24 inches. This requirement is often specified in the National Electrical Code (NEC) to ensure adequate protection for the conduit as it passes beneath driveways where vehicles may exert significant weight. The 24-inch depth helps to mitigate the risk of damage from surface loads, and it provides a sufficient buffer to avoid accidental contact with the conduit during landscaping or construction activities. This depth is especially important in areas with high traffic, such as a retail shopping center, where heavy vehicles are prevalent. By ensuring that the conduit is buried to this depth, you can maintain both safety and compliance with electrical regulations. The other options, while they may seem reasonable, do not align with the NEC requirements for the protection of rigid metal conduit in this particular scenario. While deeper installations can provide more protection, they exceed the minimum requirements set forth and may not be necessary depending on the circumstances of the installation.