What OSI physical layer term describes the capacity at which a medium can carry data?

• A. Bandwidth
• B. IEEE
• C. EIA/TIA
• D. Air

Answer: (A)

Bandwidth is the capacity of a transmission medium to carry data, and in the OSI physical layer it denotes the maximum data rate the medium can support under ideal conditions. This capacity is determined by the channel’s usable frequency range and the signaling method used, and it’s typically expressed in bits per second. In practice, the actual throughput can be lower due to overhead, protocol efficiency, and network load. Standards bodies like IEEE and EIA/TIA set specifications and interfaces, but they describe how things connect and operate, not the medium’s maximum carrying capacity. The term “air” doesn’t describe a measurable data-carrying capacity. So bandwidth is the term that captures the medium’s ability to carry data.