Which frequency range is known as the LF frequency range?

The LF (Low Frequency) frequency range is defined as 30-300 KHz. This range is used for various forms of communication, including longwave broadcasting, navigation systems, and some data transmission applications. LF waves can travel long distances, especially over water, which is beneficial for maritime communication and navigation. Their longer wavelengths make them suitable for ground wave propagation, allowing signals to follow the curvature of the Earth.

Other frequency ranges mentioned in the choices are categorized differently, which helps to establish the unique identification of LF. The range from 3-30 KHz is classified as Very Low Frequency (VLF), while the range of 300-3000 KHz falls into the Medium Frequency (MF) category. Additionally, the 30-300 GHz range is categorized as Extremely High Frequency (EHF) and is primarily used for satellite communications and some radar systems, which further differentiates it from the LF range. Thus, option B correctly defines the LF frequency range as 30-300 KHz.