Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

6.8 below the visible

267 views

Published on

Published in: Technology, Business
  • Download The Complete Lean Belly Breakthrough Program with Special Discount. ▲▲▲ http://scamcb.com/bkfitness3/pdf
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Download The Complete Lean Belly Breakthrough Program with Special Discount. ●●● http://ishbv.com/bkfitness3/pdf
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

6.8 below the visible

  1. 1. 6.8 Below the visible 28 January 2015 Name the types of electromagnetic radiation with wavelengths greater than visible light
  2. 2. Aims • Describe the electromagnetic radiation with wavelengths longer than visible light • Use the wave model to explain the behaviour of waves
  3. 3. Radio waves
  4. 4. Radiowaves • Communications: TV, mobile phones, local radio, police
  5. 5. Microwaves
  6. 6. Microwaves • Microwaves ovens, communicating with satellites, RADAR
  7. 7. How do microwave ovens work? • Microwaves are produced by a magnetron • Reflected by metal on the inside of the oven • Absorbed by the food • Not very good absorption so they go through the food rather than be absorbed by the surface
  8. 8. Microwave communication
  9. 9. Infra-red
  10. 10. Infra-red • Search and rescue teams, detect circulation problems, (cancer, arthritis), astronomy, burglar alarms
  11. 11. Questions • Light, long-wavelength infrared, short- wavelength infrared • Which of the above: – Can be detected by the human eye? – Can pass through glass? – Is emitted by red hot objects?
  12. 12. Questions • Explain why a metal bar starts to glow red when it is heated up • Infra-red has a heating effect on most solids. What does this tell you about whether this radiation is reflected, transmitted or absorbed • A TV remote control emits an infrared beam that carries coded information to the TV set. Explain how you might use this to find out which everyday material absorb infrared and which transmit it. • List three uses of microwaves.

×