What OSI physical layer term describes the physical medium which uses electrical pulses?

• A. fiber-optic cable
• B. air
• C. copper cable
• D. goodput

Answer: (C)

In the OSI physical layer, the medium and how signals are carried are the focus. Electrical pulses are voltages or current changes that travel along a conductor, which is exactly what copper cables do. Copper (like twisted-pair or coaxial) carries data by changing electrical signals as bits.

Fiber-optic cables, by contrast, carry light through glass, not electricity. Air is used for wireless transmission, which sends electromagnetic waves through the air rather than electrical pulses in a conductor. Goodput is a performance measure, not a transmission medium.

So the medium described as using electrical pulses is copper cable.