THE ELECTROMAGNETIC SPECTRUM
The electromagnetic waves can be classified, according to their wavelength λ in vacuum, in the following way:
|
TYPE OF ELECTROMAGNETIC WAVE |
WAVELENGTH λ |
WAVELENGTH λ(m) |
FREQUENCY |
FREQUENCY (HZ) |
|
RADIO WAVES: |
|
|
|
|
|
LF (Low Frequency) |
10 km – 1 km |
(10 – 1) x 103 |
30 kHz – 300 kHz |
(30 – 300) x 103 |
|
MF (Medium Frequency) |
1 km – 100 m |
(1 x 103) – 100 |
300 kHz – 3 MHz |
(300 x 103) – (3 x 106) |
|
HF (High Frequency) |
100 m – 10 m |
100 – 10 |
3 MHz – 30 MHz |
(3 – 30) x 106 |
|
VHF (Very High Frequency) |
10 m – 1 m |
10 – 1 |
30 MHz – 300 MHz |
(30 – 300) x 106 |
|
UHF (Ultra High Frequency) |
1 m – 10 cm |
1 – (10 x 10-2) |
300 MHz – 3 GHz |
(300 x 106) – (3 x 109) |
|
MICROWAVES |
10 cm – 1 mm |
(10 x 10-2) – (1 x 10-3) |
3 GHz – 300 GHz |
(3 – 300) x 109 |
|
INFRARED RADIATION |
1 mm – 700 nm |
(1 x 10-3) – (700 x 10-9) |
300 GHz – 428 THz |
(300 x 109) – (428 x 1012) |
|
VISIBLE LIGHT |
700 nm – 400 nm |
(700 – 400) x 10-9 |
428 THZ – 749 THz |
(428 – 749) x 1012 |
|
ULTRAVIOLET |
400 nm – 10 nm |
(400 – 10) x 10-9 |
749 THz – 30 PHz |
(749 x 1012) – (30 x 1015) |
|
X - RAY |
10 nm – 1 pm |
(10 x 10-9) – (1 x 10-12) |
30 PHz – 300 EHz |
(30 x 1015) – (300 x 1018) |
|
γ - RAY |
≤ 1 pm |
≤ (1 x 10-12) |
≥ 300 EHz |
≥ (300 x 1018) |
