Final answer:
Navigation frequencies such as those for GPS, cellular signals, and Wi-Fi may be preset into devices and operate in the radio-wave portion of the electromagnetic spectrum, with VHF TV utilizing frequencies from 54 to 88 MHz.
Step-by-step explanation:
Navigation frequencies, such as those used for Global Positioning System (GPS) signals, cellular signals, and Wi-Fi networks, operate in the radio-wave portion of the electromagnetic spectrum and may be preset into devices. For example, GPS signals operate at 1.228 and 1.575 GHz, which are not significantly absorbed by common building materials, making them very useful for navigation and tracking purposes. These technologies are essential for a wide range of applications, including communication, transportation, and personal navigation devices.
VHF TV channels utilize frequencies in the ranges of 54 to 88 MHz. The ability to preset these frequencies into various devices is important for the operation of those devices without the need for manual tuning. Engineers and technicians working with radio frequencies must understand these concepts to properly configure and manage communication systems.