What is the VLF frequency range?

What is the VLF frequency range?

• A. 3-30 KHz
• B. 30-300 KHz
• C. 300 kHz - 3 MHz
• D. 3-30 MHz

Answer: (A)

VLF stands for Very Low Frequency, and it covers roughly 3 kHz to 30 kHz. This band sits below the LF range and above ELF, giving it very long wavelengths (about 100 km down to 10 km). Those long wavelengths interact with the earth–ionosphere waveguide, allowing signals to travel great distances and even penetrate seawater to some depth, which is why VLF is used for specialized long-range communications such as submarine links. The other options correspond to higher frequency bands: 30–300 kHz is the LF band, 300 kHz–3 MHz is MF, and 3–30 MHz is HF. Therefore, the range 3 kHz to 30 kHz is the VLF band.

VLF stands for Very Low Frequency, and it covers roughly 3 kHz to 30 kHz. This band sits below the LF range and above ELF, giving it very long wavelengths (about 100 km down to 10 km). Those long wavelengths interact with the earth–ionosphere waveguide, allowing signals to travel great distances and even penetrate seawater to some depth, which is why VLF is used for specialized long-range communications such as submarine links. The other options correspond to higher frequency bands: 30–300 kHz is the LF band, 300 kHz–3 MHz is MF, and 3–30 MHz is HF. Therefore, the range 3 kHz to 30 kHz is the VLF band.