Final answer:
Refraction is true in fiber optic cables for transmitting signals.
Step-by-step explanation:
The statement is true. Refraction is indeed useful in fiber optic cables for transmitting signals. Refraction is the bending of light as it passes from one medium to another, and it plays a crucial role in the operation of fiber optic cables. The cables are made of a core material that has a higher index of refraction than the surrounding cladding material. When light enters the core, it undergoes repeated total internal reflections, allowing the signal to travel long distances without significant loss.