Which trade size 11/4 raceways has the smallest cross-sectional area?

The correct answer is Schedule 80 PVC because it is designed to be lighter and have a thinner wall compared to other metal conduit options like RMC (Rigid Metal Conduit) and IMC (Intermediate Metal Conduit). Schedule 80 PVC is constructed from plastic, which allows for a smaller wall thickness while still providing adequate strength and protection for electrical cabling.

In addition, the cross-sectional area of a conduit is influenced by both the internal diameter and wall thickness. Schedule 80 PVC has a smaller diameter and less wall thickness than the rigid and intermediate metal conduits, which directly contributes to its smaller overall cross-sectional area. This makes it particularly useful in applications where weight and ease of installation are important.

Other options like RMC, IMC, and Rigid Metal Conduit have a more substantial wall thickness to offer additional strength and protection but consequently result in a larger cross-sectional area compared to Schedule 80 PVC. Thus, for trade size 11/4 raceways, Schedule 80 PVC provides the smallest cross-sectional area.