The Electromagnetic Spectrum

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The Electromagnetic Spectrum

  1. 1. The Electromagnetic Spectrum
  2. 2. <ul><li>The electromagnetic spectrum is the complete spectrum (or continuum) of all forms of “light” </li></ul><ul><li>An electromagnetic wave consists of electric and magnetic fields which vibrate - thus making waves. </li></ul><ul><li>Vibrations </li></ul>
  3. 3. <ul><li>The electromagnetic spectrum consists of: </li></ul><ul><li>radio waves </li></ul><ul><li>cell phone waves </li></ul><ul><li>microwaves </li></ul><ul><li>radar waves </li></ul><ul><li>infrared waves </li></ul><ul><li>visible light waves </li></ul><ul><li>ultraviolet waves </li></ul><ul><li>x-ray waves </li></ul><ul><li>gamma waves </li></ul>The Electromagnetic Spectrum
  4. 4. The Electromagnetic Spectrum
  5. 5. <ul><li>Properties of electromagnetic waves include speed , frequency and wavelength </li></ul><ul><li>Speed (s), frequency (f) and wavelength (  ) are related in the formula: </li></ul><ul><li>s = f x  </li></ul><ul><li>All light waves travel at a speed of 3 x 10 8 m/s in a vacuum </li></ul>The Electromagnetic Spectrum
  6. 6. <ul><li>All parts of the electromagnetic spectrum travel at the same speed </li></ul><ul><li>Therefore, wavelength and frequency have an indirect relationship. </li></ul><ul><li>This means that as one characteristic increases, the other decreases </li></ul><ul><li>In other words, as wavelength increases, frequency decreases </li></ul>The Electromagnetic Spectrum
  7. 7. <ul><li>As wavelength decreases, frequency will? </li></ul><ul><li>increase </li></ul><ul><li>See the relationship </li></ul>The Electromagnetic Spectrum
  8. 8. <ul><li>Electromagnetic wave characteristics: </li></ul><ul><ul><li>short wavelengths have a high frequency </li></ul></ul><ul><ul><li>long wavelengths have a low frequency </li></ul></ul><ul><li>Electromagnetic waves & Energy: </li></ul><ul><ul><li>high frequency waves have high energy </li></ul></ul><ul><ul><li>low frequency waves have low energy </li></ul></ul>The Electromagnetic Spectrum
  9. 9. <ul><li>Fill in the table below: </li></ul>The Electromagnetic Spectrum wavelength frequency energy long high
  10. 10. The Electromagnetic Spectrum increasing frequency increasing energy If you haven’t already, sketch this drawing into your notes. Don’t worry so much about the actual wavelengths, just get the general shape and where the various forms of light (radio, infrared, x-ray, etc) exist. smaller wavelengths
  11. 11. The Electromagnetic Spectrum
  12. 12. <ul><li>Longer than radio, shorter than infrared or visible light </li></ul><ul><li>Wavelength 1 x 10 - 4 m to 1 x 10 -1 m </li></ul><ul><li>used for communication, medicine and consumer use (microwave ovens) </li></ul>The Electromagnetic Spectrum
  13. 13. <ul><li>Low energy waves with long wavelengths </li></ul><ul><li>Includes FM, AM, radar and TV waves </li></ul><ul><li>Wavelengths of 10 -1 m and longer </li></ul><ul><li>Low frequency </li></ul><ul><li>Used in many devices such as remote control items, cell phones, wireless devices, etc. </li></ul>The Electromagnetic Spectrum
  14. 14. <ul><li>Invisible electromagnetic waves that are detected as heat </li></ul><ul><li>Can be detected with special devices such as night goggles </li></ul><ul><li>Used in heat lamps </li></ul><ul><li>Higher energy than microwaves but lower than visible light </li></ul>The Electromagnetic Spectrum
  15. 15. <ul><li>The portion of the electromagnetic spectrum that human eyes can detect </li></ul><ul><li>ROY G BIV (red, orange, yellow, green, blue, indigo, violet) </li></ul><ul><li>Which color has the lowest frequency? </li></ul><ul><li>red has the lowest frequency – violet the highest </li></ul>The Electromagnetic Spectrum
  16. 16. The Electromagnetic Spectrum
  17. 17. <ul><li>Higher energy than light waves </li></ul><ul><li>Can cause skin cancer and blindness in humans </li></ul><ul><li>Used in tanning beds and sterilizing equipment </li></ul>The Electromagnetic Spectrum
  18. 18. <ul><li>High energy waves </li></ul><ul><li>Used in medicine, industry and astronomy </li></ul><ul><li>Can cause cancer </li></ul>The Electromagnetic Spectrum
  19. 19. <ul><li>Highest energy </li></ul><ul><li>Blocked from Earth’s surface by atmosphere </li></ul>The Electromagnetic Spectrum
  20. 20. The Electromagnetic Spectrum
  21. 21. <ul><li>What is the relationship between frequency and wavelength? </li></ul><ul><li>What characteristic of gamma waves gives them their high energy? </li></ul><ul><li>What does ROY G BIV mean? What part of the electromagnetic spectrum does it refer to? </li></ul>The Electromagnetic Spectrum
  22. 22. <ul><li>Which color is more energetic, red or yellow? </li></ul><ul><li>Which type of wave travels faster, gamma or radio? </li></ul><ul><li>Why are microwaves more dangerous than radio waves? </li></ul>The Electromagnetic Spectrum
  23. 23. <ul><li>You have just been involved in a traffic incident that leaves you stranded on the side of the road. Which part of the electromagnetic spectrum would be of the most use to you and why? </li></ul>The Electromagnetic Spectrum
  24. 24. <ul><li>Frequency and wavelength are properties of waves and since speed is constant for em waves, as frequency increases, wavelength decreases. In other words, they have an indirect relationship. </li></ul><ul><li>Gamma waves get their high energy from their extremely short wavelengths (or extremely fast frequency) </li></ul><ul><li>ROY G BIV stands for “red, orange, yellow, green, blue, indigo, and violet. They are the colors of the visible light in order of longest wavelength to shortest wavelength. </li></ul><ul><li>Yellow is more energetic than red because it has a shorter wavelength (or larger frequency) </li></ul><ul><li>Gamma waves and radio waves travel at the same speed </li></ul><ul><li>Microwaves are more dangerous than radio waves because they have a higher frequency and carry more energy. </li></ul>The Electromagnetic Spectrum

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