Final answer:
Wire size refers only to the diameter of the conducting material, excluding insulation, which makes the statement true. High-voltage transmission lines are typically bare and not insulated since air serves as insulation and the high towers prevent short circuits. Copper is commonly used for wiring because of its low resistivity, high tensile strength, and ductility.
Step-by-step explanation:
True or false: Wire size is determined by conductor diameter and does not include the insulation. The statement is true. Wire size, often measured in gauge, strictly refers to the diameter of the conducting material itself and not the insulation around it. In high-voltage applications, those tall metal-frame towers are indeed connected by wires held up by insulating connectors. However, these high-voltage wires are typically not wrapped in insulating material due to the air around them acting as an insulator and because the towers are tall enough to keep the wires away from any objects that could cause a short circuit. So, the correct answer to the given true or false question is false.
Understanding wire gauge is important as it directly influences the current-carrying capacity of the wire. For example, 10-gauge wire is thicker and has a larger diameter than 14-gauge, granting it a higher current-carrying capacity. The diameter of the wire has a role in determining the resistance and the drift velocity of electrons. Thicker wires have a lower resistance and higher current capacity.
Copper is a popular choice for wiring is due to its low resistivity, high tensile strength, and its ductility, which makes it ideal for drawing into wires. However, other materials like aluminum or precious metals like silver and gold may also be used for specialized applications. Extra care must be taken with certain materials like aluminum due to issues such as a higher thermal expansion rate and non-conductive oxidation, which could pose fire hazards or connectivity issues.
False - wood, being an insulator, can still conduct electricity if the potential difference is high enough, as is the case with lightning.
Regarding circuit diagrams and voltage, it is false that the voltage is the same at every point in a wire. Voltage can vary across different components and lengths of wire if there are differences in resistance and current flow within the circuit.