Bandas de frequência:
Gabarito letra D seria no modo Convencional ( Obs: esse sistema está migrando para o digital)
3–30 Hz105–104 km Extremely low frequency ELF
30–300 Hz104–103 km Super low frequency SLF
300–3000 Hz103–100 km Ultra low frequency ULF
3–30 kHz100–10 km Very low frequency VLF
30–300 kHz10–1 km Low frequency LF
300 kHz – 3 MHz 1km – 100 m Medium frequency MF
3–30 MHz100–10m High frequency HF
30–300 MHz10–1m Very high frequency VHF
300 MHz – 3 GHz1m – 10 cm Ultra high frequency UHF
3–30 GHz10–1 cm Super high frequency SHF
30–300 GHz1 cm – 1 mm Extremely high frequency EHF
300 GHz – 3000 GHz1 mm – 0.1 mm Tremendously high frequency THF