Intro to Millwright Practice Exam

Which beam is characterized by its U-shaped cross section?

1. Angle Iron

2. Channel Iron

3. I-Beam

4. Box Beam

The correct answer is: Channel Iron

Channel iron is characterized by its U-shaped cross section, which resembles a "C" or a channel. This design allows channel iron to bear significant loads, making it suitable for various structural applications, such as supports and frames in construction and manufacturing. The open top and bottom flange design contributes to its lightweight yet robust characteristics, enabling it to resist bending moments effectively while maintaining flexibility. This unique shape also facilitates the easy attachment of other materials or components, as the open ends can accommodate welding or bolting with ease. In contrast, options such as angle iron feature a distinct L-shape, while I-beams have a more pronounced vertical web connecting two horizontal flanges. Box beams, on the other hand, are closed sections that resemble a hollow rectangle. Each of these has its specific structural advantages but do not share the U-shaped cross-section attribute that distinguishes channel iron.