Final answer:
To trace a signal in a 100BaseT UTP cable, a tone generator in combination with a tone locator is used to send and detect a signal along the cable for troubleshooting or mapping purposes.
Step-by-step explanation:
To trace a signal from one end of a 100BaseT UTP cable to the other, a tone generator is the tool that can input a test signal on one end that can be detected on the other end.
The tone generator emits a signal that, when coupled with a tone locator (also known as a tone probe or tracer), helps determine the location of a cable, or test the continuity of the cable without having to access the ends of the cable that may be difficult to reach. This is a very useful tool for technicians to troubleshoot or map a network.