Cambridge IGCSE Physics · Syllabus 0625 · Waves
Electromagnetic Spectrum
What is Electromagnetic Spectrum?
The electromagnetic spectrum is the continuous family of transverse waves that all travel at the same high speed in a vacuum and need no material medium, arranged in order of increasing frequency as radio, microwave, infrared, visible, ultraviolet, X-ray and gamma.
This definition is part of the Waves chapter in Cambridge IGCSE Physics.
Electromagnetic Spectrum in context
The electromagnetic spectrum is one continuous family of transverse waves. They all transfer energy, they all travel at the same high speed in a vacuum — far faster than sound — and they all need no material medium. In order of increasing frequency and therefore decreasing wavelength the main regions are: radio, microwave, infrared, visible, ultraviolet, X-ray, gamma. Each region is used for the jobs its particular frequency and wavelength suit, and the hazards change as you move along the spectrum: heating at the low-frequency end, and ionising damage to cells at the high-frequency end.