Which media is immune to electromagnetic interference (EMI)?

Fiber optic cable, represented by 100Base-FX in this context, is immune to electromagnetic interference (EMI) because it transmits data using light instead of electrical signals. Unlike copper cables, which can be affected by various forms of electromagnetic interference due to the flow of electrical current, fiber optics are protected from such disturbances. Their reliance on light, contained within a glass or plastic core, means that they are unaffected by electromagnetic fields, ensuring consistent and high-quality signal transmission over long distances.

This immunity to EMI is particularly advantageous in environments with high levels of electromagnetic noise, like industrial settings or near radio transmitters, where traditional copper cables could suffer from data loss or degradation of signal quality. This characteristic is one of the key reasons why fiber optic technology has become increasingly popular for networking, especially in high-performance and mission-critical applications.

Other options include various types of copper cabling, such as coaxial cable and twisted pair cable. These types can experience interference, which can impact their performance and reliability in certain environments. 100Base-TX, which refers to Fast Ethernet over twisted pair cabling, is similarly susceptible to EMI.