Which type of media uses electromagnetic waves that are generated by lasers, is often used in campus backbones, and is capable of transmitting to a distance of 60 kilometers?

Shielded twisted-pair cable is a copper medium that transmits electrical signals rather than laser-generated electromagnetic waves, and its maximum usable distance is approximately 100 meters.

Coaxial cable is also a copper-based medium using electrical signals, not laser light, and cannot support 60 km transmission distances without significant signal amplification infrastructure.

Multimode fiber uses a wider 50 or 62.5-micron core that allows multiple light paths, causing modal dispersion that limits practical transmission distances to roughly 550 meters to 2 km - far short of 60 km.

Single-mode fiber uses a narrow 9-micron core that confines laser light to a single propagation path, eliminating modal dispersion. This design enables transmission distances of 60 km or more without signal regeneration, which is why it is the preferred medium for campus backbone and wide-area connections.