Electromagnetic Spectrum

Question 1

Describe ELF.

Answer 1

Extremely low frequency
ELF
ITU Band: 1
Freq / Wavelength: 3–30 Hz / 100,000 km – 10,000 km
Ex: Communication with submarines

Question 2

Describe SLF.

Answer 2

Super low frequency
SLF
ITU Band: 2
Freq / Wavelength: 30–300 Hz / 10,000 km – 1000 km
Ex: Communication with submarines, AC power grids

Question 3

Describe ULF.

Answer 3

Ultra low frequency
ULF
ITU Band: 3
Freq / Wavelength: 300–3000 Hz / 1000 km – 100 km
Ex: Communication within mines

Question 4

Describe VLF.

Answer 4

Very low frequency
VLF
ITU Band: 4
Freq / Wavelength: 3–30 kHz / 100 km – 10 km
Ex: Submarine communication, avalanche
beacons, wireless heart rate monitors,
geophysics

Question 5

Describe LF.

Answer 5

Low frequency
LF
ITU Band: 5
Ex: Freq / Wavelength: 30–300 kHz / 10 km – 1 km
Navigation, time signals, AM long-wave broadcasting

Question 6

Describe MF.

Answer 6

Medium frequency
MF
ITU Band: 6
Ex: Freq / Wavelength: 300–3000 kHz / 1 km – 100 m
AM (Medium-wave) broadcasts

Question 7

Describe HF.

Answer 7

High frequency
HF
ITU Band: 7-8
Freq / Wavelength: 3–30 MHz / 100 m – 10 m
Ex: Shortwave broadcasts, amateur radio
and over-the-horizon aviation
communications

Question 8

Describe VHF.

Answer 8

Very high frequency
VHF
ITU Band: 9
Freq / Wavelength: 30–300 MHz / 10 m – 1 m
Ex: FM, television broadcasts and line-of sight ground-to-aircraft and aircraft-to aircraft communications

Question 9

Describe UHF.

Answer 9

Ultra high frequency
UHF
ITU Band: 10
Freq / Wavelength: 300–3000 MHz / 1 m – 100 mm
Ex: television broadcasts, microwave ovens, mobile phones, wireless LAN, Bluetooth, and Two-Way Radios such as FRS and GMRS Radios

Question 10

Describe SHF.

Answer 10

Super high frequency
SHF
ITU Band: 11
Freq / Wavelength: 3–30 GHz / 100 mm – 10 mm
Ex: microwave devices, wireless LAN, most modern Radars

Question 11

Describe EHF.

Answer 11

Extremely high frequency
EHF
ITU Band: 12
Freq / Wavelength: 30–300 GHz / 10 mm – 1 mm
Ex: Radio astronomy, high-speed microwave radio relay