Final answer:
The claim that mechanical splicing is the most accurate and durable for optical fibers is false; fusion splicing is superior. Refraction is necessary for signal transmission in fiber optic cables, making it true. High-voltage wires are held by insulating connectors but are usually bare, not insulated.
Step-by-step explanation:
The statement that mechanical splicing is the most accurate and durable method for joining two optical fibers is false. While mechanical splicing is a common method for connecting fibers, it is generally considered to be less reliable and accurate compared to fusion splicing, which uses heat to merge the fibers together in a seamless joint. Mechanical splicing uses a mechanical fixture to align and hold the fibers in place, which can be less precise and can create higher loss at the splice joint over time.
Regarding the second question: Refraction is indeed useful in fiber optic cables for transmitting signals, making option b. True the correct answer. Refraction is a phenomenon where light changes direction as it passes from one medium to another with a different density, which is essential for keeping the light signals within the core of the optical fiber, allowing for long-distance communication with minimal loss.
The high-voltage wires attached to tall metal-frame towers are indeed held aloft by insulating connectors, but these wires are not commonly wrapped in insulating material; they are typically bare due to the high costs and impracticality of insulating such long spans of wire. Therefore, statement 16 is false.