What kind of transmission medium is most appropriate to carry data in a…

Concept

A transmission medium carries information either as an electrical signal in a conductor or as light in a dielectric waveguide. Electromagnetic interference can induce unwanted voltage or current only when the data path couples to an external electromagnetic field.

Therefore, immunity to electrical interference depends on the signal mechanism and material of the medium, not merely on its nominal data rate.

Application

1. Unshielded twisted pair and coaxial cable use copper conductors and electrical signalling. Twisting or shielding reduces coupled noise, but it does not make a conductive data path intrinsically immune to electromagnetic interference.

2. Optical fiber guides pulses of light through a glass or plastic core. Because the data path is nonconductive and does not carry an electrical signal, external electromagnetic fields do not corrupt that signal.

Cross-check

Compare the offered values by their transmission mechanism:

• Unshielded twisted pair: electrical signalling over unshielded copper pairs; twisting provides some noise rejection.

• Coaxial cable: electrical signalling over a copper core with a surrounding shield; the shield improves resistance to interference.

• Optical fiber: optical signalling through a dielectric core; it is immune to electromagnetic interference.

• More than one of the above and None of the above: these set-level choices conflict with the comparison because exactly one listed medium is intrinsically immune.

Result

Hence, the most appropriate offered medium for a network exposed to electrical interference is optical fiber.