Which term refers to the large iron or steel beam used for building bridges?

• A. Nose Cone
• B. Mast
• C. Girder
• D. Pier

Answer: (C)

The concept here is recognizing the specific term for the main load-bearing beam in bridge construction. In many bridges, the long, strong iron or steel member that carries most of the load from the deck and transfers it to the supports is called a girder. Girders are designed to resist bending and shear as vehicles push down on the roadway, so they often come in strong cross-sections like I-beams or box girders. They run along the length of the bridge between piers or abutments, forming the primary structural backbone.

A pier is a vertical support that holds up the bridge, not the long beam that spans between supports. A mast refers to a vertical or inclined spar on ships or certain towers, and a nose cone is part of a rocket or missile. So the large beam used in bridge construction is the girder.