In the context of copper cable, what does the term "impedance" refer to?

Impedance in the context of copper cable refers to the resistance the cable presents to the flow of electrical signals. This concept encompasses not just the pure resistance (ohmic resistance) but also includes the effects of inductance and capacitance that can influence how signals propagate through the cable over different frequencies.

When considering transmission lines like copper cables, impedance is critical because it determines how well the cable can transmit signals without reflections or loss. If the impedance of the cable does not match the impedance of the connected devices, it can lead to signal integrity issues, such as reflections, which could distort the transmitted signal or decrease overall performance.

In contrast, the other aspects mentioned in the remaining options do not accurately define impedance. The speed of the electrical signal is more related to the propagation velocity determined by the medium's physical characteristics. The capacity to transmit power is influenced by the cable's gauge and length but does not directly define impedance. Lastly, the frequency range pertains to the operational bandwidth of the cable, rather than the impedance itself. Thus, the definition of impedance accurately captures the relationship between the cable and the flow of electrical signals.