NCTI Introduction to Networking – Wireless Practice Test

A passive injector’s job is to place DC voltage onto a CAT-5e cable to power remote Ethernet devices. It sits in the path between the power source and the Ethernet link and adds power to the wires without altering the data signal. This is common in PoE deployments where a device like an IP camera or wireless access point can be powered over the same cable that carries data. It’s described as passive because it doesn’t negotiate or regulate power; it simply injects DC onto the cable. It does not convert DC to AC, it does not amplify the RF data signal, and it does not act as a wireless repeater.