Paragraphs with different frequencies are named as radio waves (3 kHz-3000 GHz), infrared rays, visible rays, ultraviolet rays, X rays, gamma rays and cosmic rays. Different colors of light travel at the same speed in vacuum, but their wavelengths are different, so their frequencies are different. The longer the wavelength, the smaller the frequency, the shorter the wavelength and the greater the frequency. The band frequency range of ultraviolet light is about 8× 10 14 to 3×10/7 Hz, and that of visible light is 3.9×10/4 to 7.7× 10.
X-rays are characterized by short wavelength and high frequency.
Radio waves can be divided into long wave, medium wave, short wave, microwave and mixed wave according to wavelength; According to frequency, it can be divided into low frequency, high frequency, ultrahigh frequency and ultrahigh frequency.
1? High frequency. Namely, medium wave and short wave. The wavelength is 10 ~ 3000m, and the frequency is 10 5 ~ 3× l0 7Hz, such as induction heating equipment for high-frequency quenching, melting, welding and cutting, high-frequency medium heating equipment, plastic processing and food drying equipment, radio broadcasting and communication.
2? Uhf. That is, the short wave is1~10m, and the frequency is 3× 10 7 ~ 3× l0 8Hz, such as radio communication, TV signal transmission, medical electrical equipment, electrified railways, etc.
3? Uhf. Namely microwave. Wavelength 1 ~ < 0.07m, frequency 3× l0 8 ~ 3× l0 10hz, radio positioning, navigation, radar, etc. Is the source of artificial electromagnetic waves.