Certified Fiber Optics Practice Exam

The tensile strength of a fiber is affected when it is what?

1. Bent

2. Stretched

3. Twisted

4. Cut

The correct answer is: Bent

The tensile strength of a fiber refers to its ability to withstand tension without breaking. When a fiber is bent, the internal structure is subjected to different stress levels that can weaken the material over time. Bending creates a point of compression on one side of the fiber and tension on the opposite side. This alteration in the stress distribution can lead to micro-cracks or other forms of structural failure, ultimately reducing the fiber's overall tensile strength. While stretching can also affect tensile strength, it generally involves applying force along the length of the fiber without changing its geometry significantly. Twisting affects the fiber's configuration but does not mainly impact tensile strength in the same way bending does. Cutting the fiber would fully sever it, leading to a total loss of tensile strength at that point, rather than a degradation of its strength characteristics due to stress. Thus, bending poses a more direct and significant risk to the tensile integrity of fiber.