Radiation and Characteristics

• Electromagnetic Energy


  Radiant energy that travels in waves at the speed of light (3 x 10^8 m/s)

  
• Electromagnetic Energy


  • In classical physics, it is the transfer of radiant energy at the speed of light through free space, matter, or medium in the form of electromagnetic waves
  • Travels in the form of waves
  • Can also be described as radiant energy, electromagnetic radiation, electromagnetic waves, light, or the movement of radiation
• Types of Electromagnetic Energy

  • Radiowaves
  • Microwaves
  • Infrared
  • Visible Light
  • Ultraviolet Rays
  • X-rays
  • Gamma Rays

  
• Wave


  • A disturbance that travels through space and time, usually accompanied by the transfer of energy
  • Waves travel and the wave motion transfers energy from one point to another
• Electromagnetic Waves


  Formed when there is a continuing process of an electric field developing a magnetic field and vice versa
• Wave Train


  • When several waves are travelling along a medium, the continuous group of waves is called a wave train
  • 1 wave = 1 cycle of crest and trough

  
• Sine Wave


  • A mathematical function that describes a smooth repetitive oscillation
  • Most frequently used diagram or wave form in demonstrating electromagnetic radiation

  
• Parts of a Wave

  • Wave Crest (Highest point of the wave)
  • Wave Trough (Lowest point of the wave)
  • Wavelength (Distance between waves)
  • Wave Height (Vertical distance between the crest and the trough)
  • Amplitude (Difference from the straight line that traverses the waves)

  
• Wavelength


  The distance from one crest to another, from one valley to another, from any point on the sine wave to the next corresponding point

  
• Amplitude


  • One half of the height from the peak of a crest to the lowest point of wave
  • One half of the range from crest to valley over which the sine wave varies

  
• Frequency and wavelength


  Inversely proportional

  
• Photon energy and frequency

  Directly proportional

  
• Photon energy and wavelength

  Inversely proportional

  
• Frequency increases


  Wavelength gets shorter
• Frequency of photon increases (wavelength gets shorter)


  Amount of energy in each photon increases

  
• Increasing the energy of photon

  Increases the frequency and decreases the wavelength

  
• Velocity (c)


  • The product of frequency and wavelength always equals the velocity of light for electromagnetic energy
  • Unit is in meter per second (m/s) or miles per second (Mi/s, M/s)
  • Electromagnetic waves travel with speed of light (3 x 10^8 m/s)

  
• Frequency (v)


  • Refers to the number of oscillations per unit time
  • Usually identified as cycles per second (cps)
  • The rate of rise and fall
  • The number of crest or the number of valleys that pass the point of an observer per unit of time
  • Represented by Greek letter nu (v)
  • Unit of measurement is Hertz (Hz)
• Wavelength (λ)


  • The distance from one crest to another, from one valley to another, or from any point on the sine wave to the next corresponding point
  • Represented by Greek letter lambda (λ)
  • Unit of measurement is Angstrom (Å) and nanometer (nm)

  
• Electromagnetic Wave Equation