Final answer:
Refraction is useful in fiber optic cables for transmitting signals.
Step-by-step explanation:
True. Refraction is useful in fiber optic cables for transmitting signals.
Refraction is the bending of light as it passes from one medium to another with a different refractive index. In fiber optic cables, the light signals are transmitted through thin fibers of plastic or glass. When the light enters the fiber at an angle greater than the critical angle, it is totally reflected due to total internal reflection and guided along the fiber by repeatedly reflecting off the inner surface. This allows the signals to be transmitted long distances without significant loss of strength or quality.