Features of Electromagnetic Waves




To find out more about the diagram above . . . . read on!

Features of Electromagnetic Waves

Look carefully at the diagram at the top of the page. Now check out the following questions (and answers)!

  1. Do all light waves propagate through a vacuum in a straight line?
  2. What is the term for the lowest point in the oscillation of a wave?
  3. Is wavelength measured between the crests of successive waves?
  4. What does the frequency of a wave measure?
  5. What speed does light travel at in a vacuum??

About the Diagram

Introducing the diagram! Read back and forward between the image at the top of the page and the explanation below!

This diagram shows the key features of electromagnetic (light) waves and introduces some of the terms used to describe them.

  • Across the centre is an electromagnetic wave, shown in red.
  • The wave is travelling from left to right.
  • The different features of the wave are shown by labels.
  • At the bottom of the diagram are short definitions of key terms.

Remember that:

  • Electromagnetic radiation (light) is often described in terms of waves.
  • Electromagnetic waves, which are a form of electromagnetic radiation, propagate from a light source, travel through space, and encounter different materials.
  • Visible light corresponds with the range of wavelengths of electromagnetic radiation that are responsible for the sense of sight.
  • Visible light is a form of electromagnetic radiation, as are radio waves, infrared radiation, ultraviolet radiation, X-rays and microwaves.
  • The range of wavelengths that produce visible light forms a very small part of the electromagnetic spectrum.
  • Visible light is perceived as colour. The colour red has been chosen to correspond with the wavelength of this wave.

Follow the blue links for definitions . . . . or check the summaries of key terms below!

Some Key Terms

Move to the next level! Check out the following terms.

Electromagnetic wave

An electromagnetic wave carries electromagnetic radiation. An electromagnetic wave is formed as electromagnetic radiation propagates from a light source, travels ...
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The frequency of electromagnetic radiation (light) refers to the number of wave-cycles of an electromagnetic wave that pass a given ...
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Any material through which an electromagnetic wave propagates (travels) is called a medium (plural media). In optics, a medium is ...
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Speed of light

The speed (or velocity) of a light wave is a measurement of how far it travels in a certain time ...
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A wave-cycle refers to the path of a wave measured from any point through the course of a single oscillation ...
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Wavelength is a measurement from any point on the path of a wave to the same point on its next ...
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