electro magnetic spectrum

• What is the objective of studying the Electromagnetic Spectrum?


  To understand the parts of the EM spectrum, what all EM waves have in common, and their uses and dangers
• How were electricity and magnetism viewed until the 19th century?


  They were seen as different branches of science
• What does the Law of Electromagnetic Induction describe?


  How a changing magnetic field creates a force on electrical charges
• What did Maxwell's equations demonstrate about electric and magnetic forces?


  They are two complementary aspects of electromagnetism
• Whats the velocity of electromagnetic waves?

  310,740,000 m/s
• What is the speed of light?


  Approximately $3 \times 10^8 \text{ m/s}$
• What are electromagnetic waves?


  Vibrations of electric and magnetic fields that transfer energy
• What type of waves are electromagnetic waves?


  Transverse waves
• Can electromagnetic waves travel through a vacuum?


  Yes, they can travel through a vacuum
• What does the energy transferred by electromagnetic waves depend on?


  The wavelength of the waves
• What common behaviors do all electromagnetic waves exhibit?


  They can be reflected, refracted, diffracted, and absorbed/transmitted
• What is the wave equation that all electromagnetic waves obey?


  Higher frequency EM waves carry more energy
• What are the types of electromagnetic waves in order of frequency or wavelength?


  • Radio Waves
  • Microwaves
  • Infrared
  • Visible Light
  • Ultraviolet
  • X-Rays
  • Gamma Rays
• What are the uses of different types of electromagnetic waves?


  • Radio: Communication (TV, mobile)
  • Microwaves: Cooking, optical fiber
  • Infrared: Heaters, night vision
  • Visible: Vision, photography
  • Ultraviolet: Tanning, medical imaging
  • X-Rays: Security screening, medical imaging
  • Gamma Rays: Sterilizing, food preserving
• What are the dangers associated with different types of electromagnetic waves?


  • Radio Waves: Usually harmless
  • Microwaves: Can heat tissue
  • Infrared: Can burn skin
  • Ultraviolet: Can cause sunburn and skin cancer
  • X-Rays: May damage cells and cause cancer
  • Gamma Rays: Damages cells and may cause cancer
• What are the sources of different types of electromagnetic waves?


  • Radio Waves: Transmitters
  • Microwaves: Magnetron, hot objects
  • Infrared: Sun, LEDs, lasers
  • Visible: Glow worms, very hot objects
  • X-Rays: X-ray tubes, radioactive nuclei
  • Gamma Rays: Detectors, Geiger-Muller tubes
• How does the information capacity of radio waves compare to that of other electromagnetic waves?

  Radio waves have lower information capacity than higher frequency EM waves
• What is the relationship between frequency and energy in electromagnetic waves?

  Higher frequency EM waves carry more energy
• The electromagnetic spectrum is the range of all possible wavelengths or frequencies of electromagnetic radiation.
• Electromagnetic waves are transverse waves that do not require a medium to travel through, unlike sound waves which need air molecules to vibrate.
• Radio waves have the longest wavelengths and lowest frequency, while gamma rays have the shortest wavelengths and highest frequency.