Final answer:
Reading a wire identification code reveals information such as the circuit function, wire size, and wire segment, which are all critical for electrical work. The correct option is D.
Step-by-step explanation:
Based on Figure 20.41, if the four wires are made from the same material, the following statements are true:
Resistance of Wire 1 > Resistance of Wire 2
Resistance of Wire 4 < Resistance of Wire 3
Resistance is a measure of how difficult it is for current to flow through a wire. Therefore, when wires are made from the same material, the factors that determine resistance are the length and cross-sectional area of the wire. In this case, Wire 1 has a higher resistance than Wire 2 because it is longer or has a smaller cross-sectional area. When reading a wire identification code, you can gain various types of information about the wire in question.
This can include the circuit function, indicating what the wire is used for within the electrical system; the wire size, which refers to the gauge or diameter of the wire and can be indicative of the wire's capacity to carry current; and the wire segment, which can give you an idea of the length or specific section of the wire in a larger network. Knowing these details is crucial for proper electrical installation, maintenance, and repair. For example, a device for measuring gauge can be used to determine higher gauge numbers for thinner wires, which influences the wire's resistance to electrical current.