What type of cable must be twisted pair, low capacitance, and have 120-ohm characteristic impedance?

Twisted pair cables are essential for certain digital communication applications, and in this case, DMX cable is specifically designed to meet those requirements. DMX, which stands for Digital Multiplex, is predominantly used in stage lighting control systems.

The characteristic impedance of 120 ohms is a defining trait of DMX cables, making them suitable for long runs with minimal signal degradation. The low capacitance feature allows multiple DMX devices to be connected over long distances without losing signal integrity, which is crucial in live performance and theatrical settings.

In contrast, the other types of cables mentioned serve different purposes. Power cables are designed to carry electrical power and don’t have the specific characteristics required for data transmission. Speaker cables are focused on delivering audio signals and typically have lower impedance values, while coaxial cables are generally used for high-frequency signals and have a different impedance profile, commonly at 75 ohms. Therefore, DMX cable aligns perfectly with the specifications of twisted pair, low capacitance, and 120-ohm impedance.