Final answer:
The statement about high-voltage wires being wrapped in insulating material is false; air serves as the insulator. It's also false that voltage is the same at every point in a given wire in a circuit diagram. Lastly, refraction is indeed useful in fiber optic cables and is a key principle in their operation.The statement is true.
Step-by-step explanation:
The statement regarding high-voltage wires is false. While the high-voltage wires are indeed held aloft by insulating connectors, typically these wires are not wrapped in an insulating material. This is because the air acts as a natural insulator, and the height of the towers prevents people from coming into contact with the live wires.
For the GRASP CHECK on circuit diagrams, the statement is false. Within a given wire in a circuit diagram that includes components such as resistors or other electrical devices, the voltage is not the same at every point due to the potential difference that will occur across these devices.
In regards to refraction being useful in fiber optic cables, the statement is true. Refraction is a phenomenon where the direction of light changes as it passes from one medium to another. In fiber optic cables, refraction is leveraged to guide light through the cable, which allows for efficient signal transmission.