A radio system uses frequencies that penetrate buildings and structures but are not effective for long-range use. Which band best describes these frequencies?

• A. VHF
• B. UHF
• C. Trunked system
• D. Duplex

Answer: (B)

Frequencies determine how a radio wave travels: higher frequencies lose signal strength more quickly with distance, so long-range use is harder, while their shorter wavelengths can interact with structures in a way that allows penetration into buildings. The frequencies described as penetrating buildings and structures but not being effective for long-range fit the UHF band (roughly 300 MHz to 3 GHz). In urban or indoor environments, UHF signals can enter through openings and transmit through walls better than lower bands, but their higher path loss at distance means you don’t get strong long-range reach without repeaters or higher power. This combination makes UHF the best match for the scenario.