Under typical loading, which statement is true about a truss?

• A. Every member carries the same magnitude of force
• B. Only the top chord carries load
• C. The bottom chord is typically in tension and the top chord in compression
• D. Diagonal members carry no force

Answer: (C)

When a truss is loaded, its members carry forces mainly along their lengths (axial forces). The load on the joints tends to push the top chord together and pull the bottom chord apart. Because the members resist these tendencies along their axes, the top chord ends up in compression while the bottom chord is in tension. The diagonals help transfer shear between the chords, but their exact force direction depends on the specific truss configuration. Under typical roof-truss loading, the bottom chord is in tension and the top chord in compression, making that statement the true one.