Journeyman Electrician Practice Exam

What is the minimum trade size electrical metallic tubing (EMT) needed for eight size 6 AWG copper conductors in a 60-foot run?

1. 1 inch

2. 1 1/4 inches

3. 1 1/2 inches

4. 2 inches

The correct answer is: 1 1/4 inches

To determine the minimum trade size electrical metallic tubing (EMT) required for eight size 6 AWG copper conductors in a 60-foot run, we reference the National Electrical Code (NEC) guidelines on conduit fill. The NEC provides tables that specify the maximum allowable fill for conduits based on the trade size and the number of conductors, ensuring safety and maintaining proper functionality. The NEC allows for a specific percentage of the conduit to be filled with conductors. For a raceway containing more than two conductors, the maximum fill is generally limited to 40%. When calculating the fill for the conductors: - Each size 6 AWG copper conductor has a specific area. - Eight of these conductors will have a total cross-sectional area that must fit within the conduit size chosen. After consulting the NEC Conduit Fill Tables, a 1-inch EMT would not accommodate the cross-sectional area required for eight size 6 AWG conductors, as it exceeds the maximum fill percentage allowed. A 1 1/4 inch EMT, however, meets the requirements. It allows enough space to house the eight size 6 AWG conductors while adhering to NEC fill guidelines. Choosing the 1 1/4