Final answer:
The coating of wire conductors with solder is called tinning, not welding, insulating, or braiding. High-voltage wires are not insulated except at connection points. Grounding is connecting a conductor to the earth to fix it at zero volts. Therefore, the correct option is C.
Step-by-step explanation:
When wire conductors are coated with solder, the process is known as tinning. Tinning is used to help with soldering, prevent oxidation, and ensure a better electrical connection. In contrast, welding is a fabrication process that joins materials, typically metals, by causing coalescence, which is often done by melting the workpieces and adding a filler material to form a strong joint.
The statement that the high-voltage wires connected to metal-frame towers are held aloft by insulating connectors and wrapped in insulating material is false. High-voltage wires are generally bare and not insulated, except for their connection points where insulating materials are commonly used.
The connection of a conductor to the earth to fix it at zero volts is called grounding. Grounding is an important safety measure to prevent electrical shocks and damage to electrical systems.