Final answer:
The true statement regarding electric wiring is that the strength of the cable-to-terminal joint should at least equal the cable's tensile strength. Copper is prominent in electrical applications due to its low resistivity, high tensile strength, and ductility. Tension in connectors like ropes or cables is uniform along the length and exemplifies Newton's third law.
Step-by-step explanation:
The correct statement relating to electric wiring among the given options is B. When attaching a terminal to the end of an electric cable, it should be determined that the strength of the cable-to-terminal joint is at least equal to the tensile strength of the cable itself. This is to ensure that the connection does not become the weakest point of the electrical system and maintains the integrity under load. It is crucial not to underestimate the importance of a proper joint between the cable and terminal, as it needs to withstand the same tensile stress as the cable itself without failing.
Copper wires are routinely used for extension cords and house wiring because they exhibit a low resistivity, high tensile strength, and high ductility, making them ideal for electrical conductivity and cable formation. Copper, with a tensile strength of 2 × 108 N/m², endows the material with the ability to resist breaking under tension. These properties are essential for a conductor to be suitable for making wire. Other materials used for wiring include aluminum, which, while having a lower electrical conductivity than copper, is lighter and less expensive. However, it has a lower tensile strength and is less ductile, which can lead to increased risk of breakage and electrical resistance over time.
Regarding tension in a flexible connector such as a rope or cable, it is true that tension is a result of opposite forces that pull each point of the connector apart in the direction parallel to the length of the connector. The tension applies equal forces in opposite directions at the two ends of the connector, conforming to Newton's third law. These forces are transmitted through the medium, like a rope or wire, and the tension is consistent throughout the length of the connector.