Electromagnetic Spectrum

Electromagnetic Spectrum

Electromagnetic waves are energy waves that have both electric and magnetic fields. When these electromagnetic waves are classified according to their increasing order of wavelength (or decreasing order of frequency), they form the electromagnetic spectrum. Since these waves have energy they are also called electromagnetic radiation. The other types of electromagnetic radiation that make up the electromagnetic spectrum are infrared light, microwaves, X-rays, gamma-rays and ultraviolet light.

Ultraviolet: It is a type of radiation that comes from the sun. This radiation causes skin problem. “Hot” objects in space emit UV radiation as well.

Visible: Our eyes detect visible light. Fireflies, light bulbs, and stars all emit visible light.

Infrared: Night vision goggles pick up the infrared light emitted by our skin and objects with heat. In space, infrared light helps us map the dust between stars.

Gamma ray: Doctors use gamma-ray imaging to see inside your body. The biggest gamma-ray generator of all is the Universe.

X-ray: X-rays are used by the dentists to image the teeth, and airport security uses them to see through your bag. Hot gases in the Universe also emit X-rays.

Microwave: Microwave radiation will cook your popcorn in just a few minutes, but is also used by astronomers to learn about the structure of nearby galaxies.

Radio: Your radio captures radio waves emitted by radio stations, bringing your favorite tunes. Radio waves are also emitted by stars and gases in space.

It is not possible to pinpoint exact wavelengths of these radiations but they span over a range. The table below summarizes ranges of these radiations.

Electromagnetic Spectrum Wavelength Range (m) Radiation Range(nm)
Gamma Rays below \(10^{-12}\) below 1nm
X – Rays \(10^{-12 }\: to\: 10^{-9}\) 1nm to 10nm
Ultraviolet Rays \(10^{-9}\: to\: 4 \times 10^{-7}\) 10nm to 400nm
Visible Light \(4 \times 10^{-7 }\: to\: 7 \times 10^{-7}\) 400nm to 700nm
Infrared Radiation \(7.1 \times 10^{-7} \: to\: 0.001\) 700nm to 1mm
Microwaves 0.001 to 0.1 1mm to 1m
Radio Waves above 0.1 above 1m

Stay tuned with byju’s to learn more about electromagnetic spectrum, x-ray and much more.

Practise This Question

Alternating current has a constant direction.