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Depending on their wavelength range, electromagnetic waves are given different names. The figure shows the electromagnetic spectrum. What is known as visible light is the narrow band of wavelength from 400 nm (blue) to 700 nm (red). To its either side are the infrared from 700 nm to 0.3 mm and the ultraviolet from 30 nm to 400 nm. Microwaves have longer wavelength than the infrared (0.3 mm to 300 mm) and the radio waves have wavelengths longer than 300 mm. The television broadcast takes place in a small range at the end of the microwave spectrum. Those with wavelengths shorter than ultraviolet are generally called rays . Prominent among them are x-rays with wavelengths 0.03 nm t0 30 nm and  -rays with wavelengths shorter than 0.03 nm. |
